FRIDAY MORNING, 2 DECEMBER 2016 CORAL 2, 8:00 AM TO 11:45 AM Session 5aAB Animal ...

94 Pages·2016·0.8 MB·English

FRIDAYMORNING,2DECEMBER2016 CORAL2,8:00A.M.TO11:45A.M.
Session5aAB
AnimalBioacoustics:MarineAcousticEcology
JenniferL.Miksis-Olds,Chair
CenterforCoastalandOceanMapping,Univ.ofNewHampshire,24ColovosRd.,Durham,NC03824
ContributedPapers
8:00 8:30
5aAB1.Amulti-yeartimeseriesofmarinemammaldistributioninthe 5aAB3.DidhumpbackwhalesgomissingoffMaui,Hawaii?Acompari-
Alaskan Arctic. Jessica Crance and Catherine Berchok (AFSC/NMFS/ sonofsongactivitybetweenthe2014/15and2015/16breedingseasons.
NOAA,NationalMarineMammalLab.,7600SandPointWayNE,Seattle, Anke K€ugler (Marine Biology Graduate Program, Univ. of Hawaii at
WA98115,[email protected]) Manoa,2525CorreaRd.HIG132,Honolulu,HI96822,akuegler@hawaii.
edu),MarcO.Lammers(HawaiiInst.ofMarineBiology,Univ.ofHawaii
TheMarineMammalLaboratoryhasdeployedlong-term,moored,pas-
at Manoa, Kaneohe, HI), Eden J. Zang (Oceanwide Sci. Inst., Honolulu,
sive acoustic recorders at numerous locations in the Alaskan Arctic since
HI), Maxwell B. Kaplan, and T A. Mooney (Woods Hole Oceanographic
the BOEM-funded Chukchi Acoustics, Oceanography, and Zooplankton
Inst.,WoodsHole,MA)
(CHAOZ) study began in 2010. These instruments, often collocated with
oceanographic instruments, collect year-round passive acoustic data (16 Each winter,thousands ofhumpbackwhales (Megapteranovaeangliae)
kHzsamplingrate,~30%dutycycle).Allacousticrecordings(100%)were migratefromtheirhighlatitudefeedinggroundsinAlaskatomateandcalve
analyzedusinganin-houseMatlab-basedmanualanalysisprogramfor12 intheshallowtropicalwatersaroundtheMainHawaiianIslands.Population
differentArcticandsub-Arcticcetaceanandpinnipedspecies,aswellasfor estimates suggest that up to 10,000 animals winter in Hawaiian waters,
vessel, seismic airgun, and ice noise. Bowhead and beluga distributions makingupmorethanhalfofthetotalNorthPacificstock.However,inthe
showed similar patterns, with bimodal temporal distributions representing 2015/16season,anecdotalreportsfromcommercialoperatorsandresearchers
thefallandspringmigrations.Infrequentgraywhaledetections(isolatedon tellofanunusuallylownumberofwhalescomparedtopreviousyearsoffthe
nearshorerecorders)followedasimilar,albeitlessdefined,bimodaldistri- islandofMaui.Toexaminethisissue,datafromlong-termpassiveacoustic
bution.Walrusandbeardedsealcallsweredetectedalmostyear-round,with monitoringwithautonomousEcologicalAcousticRecorders(EARs)during
peakbeardedsealcallingfromAprilthroughJune.Detectionsofsub-Arctic the2014/15and2015/16seasonsoffthewestcoastofMauiwereanalyzed
species(e.g.,humpback, fin,killer,andminkewhales) wererarenorthof usingmalechorusinglevelsasaproxyforrelativewhaleabundance.Root-
70(cid:2)N.Correlationofmarinemammaldistributionwithconcurrentoceano- mean-square sound pressure levels (SPLs) were calculated to compare low
graphic parameters revealed strong associations with oceanographic and frequency acoustic energy (0-1.56 kHz) between both seasons. The data
prey variables, more specifically, ice concentration and thickness, chloro- showedthatchorusinglevelsdroppedinearlyJanuary2016.Althoughlevels
phyll,windspeed,andcurrents.Thisstudyillustratestheimportanceofcol- subsequentlyincreasedagainuntiltheypeakedinFebruaryasexpected,SPLs
lectingconcurrentlong-termpassiveacousticandoceanographicdataina remained lower than in 2014/15 throughout the remaining season. These
rapidlychangingenvironment. resultssuggestthatthenumberofsingingmaleswasindeedlowerduringthe
2015/16seasonoffwestMauiandthatfuturemonitoringiswarranted.
8:15
8:45
5aAB2.Apreliminaryacousticsurveyofecholocatingmarinemammals
in the Bering Sea. Kerri Seger (CCOM, Univ. of New Hampshire, 9331 5aAB4.Howreliableissongasacueforacousticsurveysofhumpback
Discovery Way, Apt. C, La Jolla, CA 92037, [email protected]), Jennifer whales (Megaptera novaeangliae) with changing population size and
Miksis-Olds(CCOM,Univ.ofNewHampshire,Durham,NH),andBruce density?MichaelJ.Noad,RebeccaA.Dunlop,andAmeliaMack(School
Martin(JASCORes.,Ltd.,Victoria,BC,Canada) ofVeterinarySci.,TheUniv.ofQueensland,Gatton,QLD4343,Australia,
[email protected])
As the Arctic seas rapidly change with increased ocean temperatures
anddecreasedseaiceextent,traditionalArcticmarinemammaldistributions Acousticsurveysofmarinemammalshaveseveraladvantagesovertra-
will be altered, and non-traditionally Arctic species may shift poleward. ditional visual surveys. For an acoustic survey to be accurate, however,
Arcticspeciestypicallyincludesperm,bowhead,humpback,right,gray,fin, thereneedstobeapredictablerelationshipbetweenvocalbehaviorandden-
andbluewhales;odontocetes,specificallykillerandbelugawhales;andsev- sity. Humpback whale’s song, produced by males primarily during the
eral pinnipeds species. Their acoustic presence has been documented breedingseason,ispotentiallyagoodcandidateforsuchsurveys.Thefunc-
becausetheyproducerelativelylow-frequencysoundsthataredetectableby tionofsong,however,remainsenigmaticandsoitsusefulnessasapredictor
many common, remotely-deployed recording platforms. Until recently, ofpopulationdensityisstillnotknown,particularlywhenpopulationden-
however, recording constraints of power and storage limited higher sam- sitychanges.Weexaminedaspectsofsingingbehaviorduringmigrationoff M
plingratesandpreventedthedetectionofmanyhigh-frequency-producing easternAustraliabetween1997and2015includingtheproportionofwhales A
speciesintheArcticseas.SuchspecieslikelyincludeBaird’s,Cuvier’s,and thatsang,thespacingbetweensingers,andtheuseofsongbymaleswhen RI.
Stejneger’s beaked whales, as well as Northern right whale and Pacific joiningotherwhales.Overthisperiod,therewasasix-foldincreaseinthe
F
white-sideddolphins.Usingoneofthefirstlong-termdatasetstorecordrel- populationbutthishadlittleeffectontheproportionofwhalessinging,and a
ativelyhighfrequenciesintheBeringSea,signaltypessimilartothoseof singersspacedrandomly,implyingthatitcouldbeusefulasasurveytool. 5
Baird’sandCuvier’sbeakedwhales,andPacificwhite-sidedandNorthern However, the proportion of singers that continued to sing while joining
right whale dolphins have been detected. Their relative acoustic presence otherwhalesdecreased,showingsomedensityeffectsonsingingbehavior.
fromthelastseveralyearswillbepresented,aswellastheacousticpresence Altogether, while singing behavior can be used as a reasonable proxy of
ofotherspecies,likeRisso’sdolphin,thatmaybeshiftingnorthwardinto populationsizeatthedensitiesobserved,behavioralstrategiesmaystartto
theArcticseas.[WorksupportedbyONR.] confoundthisrelationshipathigherdensities.
3359 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3359
9:00 asourceatoneormoreunderwaterhydrophones.Thisestimationtaskcan
bedifficultfornon-impulsivesources(e.g.,humpbackwhales)duetoearly
5aAB5.Thecorrelationbetweenthelocalenvironmentandgraywhale
arrivalsmaskinglaterones.Inlinearsystemanalysis,theimpulseresponse
behaviorastrackedusingasparsehydrophonearrayinMontereyBay
(IR)ofasystemisthesystemoutputwhentheinputisanimpulse(i.e.,a
NationalMarineSanctuary.ReginaA.Guazzo,JohnA.Hildebrand,Sean
shortduration,largebandwidthsignal),andexpresseshowasourcesignal
M.Wiggins,GeraldL.D’Spain(ScrippsInst.ofOceanogr.,Univ.ofCali-
interacts with the environment to yield the output waveform (e.g., that
fornia,SanDiego,UCSD/SIO/0205,9500GilmanDr.,LaJolla,CA92093-
recordedbyahydrophone).Recordingsofarelativelyimpulsivevocaliza-
0205,[email protected]),andDavidW.Weller(SouthwestFisheriesSci.
tion(e.g.,awalrusknock),giventhattheyapproximatetheIRbetweenthe
Ctr.,NOAA,LaJolla,CA)
walrusandhydrophone,mayfacilitatearrivaltimeestimation.IRestimation
Gray whales (Eschrichtius robustus) make one of the longest annual forunknown,non-impulsivecallsismorechallenging,particularlyfortime-
migrations of any marine mammal. While the seasonal periodicity of the varyingchannels.Blindchannelestimationistheprocessofestimatingthe
migrationandrelatedtravelcorridorshavebeenwell-studied,littleisknown setofIRsbetweenasingle(unknown)sourceandmultiplereceivers,and
abouthowthesewhalesuseacousticswhilemigrating.Acousticarrayproc- canpotentiallyhelpestimatedirectandinterface-reflectedarrivaltimesfor
essingisapowerfultooltolocalizeandtrackvocalizingwhaleswithoutdis- non-impulsivemarinemammalvocalizationssincetheIRscanbeanalyzed
rupting their behavior. Concurrent with the NOAA Southwest Fisheries ratherthanwaveforms/spectra.Inthispaper,weusesimulationstoexplore
ScienceCentervisualandinfraredgraywhalecensus,fourhydrophone-re- theimportanceofoceansurfacegravitywavesonblindestimationofacous-
corderpackageswithsitesseparatedbyapproximately2kmin58to110m ticIRs.
waterinMontereyBayNationalMarineSanctuaryoffshoreofGraniteCan-
9:45–10:00Break
yon,California,recordedfromNovember2014toJune2015.Anautomatic
call detector identified gray whale M3 calls in the dataset. Spectrogram
10:00
cross-correlationwasusedtomeasurethetime-difference-of-arrivalofthese
callsandestimatethelocationofthecallinganimal.Theselocalizationspro- 5aAB8. Low-frequency propagation and noise in the intertidal zone.
vide gray whale swimming and calling behavior and indicate changes on JamesS.Martin,PeterH.Rogers(SchoolofMech.Eng.,GeorgiaInst.of
dielandseasonaltimescales.Resultsfrom15high-qualitytracksshowcall- Technol., 771 Ferst Dr., Love Bldg., Rm. 115, Atlanta, GA 30332-0405,
inggraywhalesswimmingatameanspeedof1.97m/switharangeof1.18 [email protected]), Ashwin Bhandiwad, Orphal Colleye, and
to2.54m/s.Acousticdetectionsandtracksarecomparedwithenvironmen- JosephSisneros(Dept.ofPsych.,Univ.ofWashington,Seattle,WA)
talparameterstoinvestigatehowgraywhalebehaviorrelatestotheirphysi-
cal environment. These results are necessary for understanding the cues Measurements of ambient noise and short-range propagation (<2m)
graywhalesusetonavigatefromtheirfeedinggroundsoffshoreofAlaska weremadeintheintertidalzonewithwaterdepthsrangingfrom50to80
totheirbreedinggroundsinBajaCalifornia. cm using vector sensors. The sites selected for the measurements were
knownnestingareasforplainfinmidshipman(Porichthysnotatus).Malesof
9:15 this species produce continuous acoustic advertisement calls with funda-
mental frequencies in the 70 to 100 Hz range. The temporal and spectral
5aAB6. Vocalization source level distributions and pulse compression
structure of these calls must convey information regarding the source’s
gainsofdiversebaleenwhalespeciesintheGulfofMaine.DelinWang,
range, direction, and/or fitness over the maximum detectable range in a
WeiHuang,HeribertoGarcia(Elec.andComput.Eng.,NortheasternUniv.,
complexenvironment.Bothfundamentalandharmoniccomponentsappear
006 Hayden Hall, 370 Huntington Ave., Boston, MA 02115, wang.del@
tobeabovearapidlow-frequencyincreaseinthenoisefloorduetolocal
husky.neu.edu), Nicholas C. Makris (Mech. Eng., Massachusetts Inst. of
wavemotionandbelowthefrequencyrangeofseveralobservednoisetran-
Technol.,Cambridge,MA),andPurnimaRatilal(Elec.andComput.Eng.,
sientsattimeswithmodestwindspeeds(<5mph)andsmallwaveheights
NortheasternUniv.,Boston,MA)
(<20cm). There is little evidence of significant propagation differences
Thevocalizationsourceleveldistributionsandpulsecompressiongains betweenspecificfrequencieswithinthebandofinterest.
areestimatedforfourdistinctbaleenwhalespeciesintheGulfofMaine:
10:15
blue,fin,minke,andsei.Thevocalizationswerereceivedonalarge-aper-
turedenselysampledcoherenthydrophonearraysystemdeployedtomoni- 5aAB9.Passiveacousticmonitoringoffishesandacrustaceanusinga
tormarinemammalsoverinstantaneouswideareasusingthepassiveocean towed hydrophonein Tateyama bay.Ryuzo Takahashi (FisheriesTech-
acousticwaveguideremotesensingtechnique.Foreachbaleenwhalespe- nol. Dept., Japan Fisheries Res. and Education Agency, 7620-7, Hasaki,
cies, between 400 to over 1400 measured vocalizations with significantly Kamisu-shi, Ibaraki-ken 314-0408, Japan, [email protected]),
high signal-to-noiseratios (SNR>10dB) after coherentbeamforming and Tomonari Akamatsu (Japan Fisheries Res. and Education Agency, Yoko-
localizedwithhighaccuracies(<10%localizationerrors)overrangesspan- hama-shi, kanagawa-ken, Japan), Tomohito Imaizumi (Fisheries Technol.
ningroughly1kmto38kmareincludedintheanalysis.Thewhalevocal- Dept., Japan Fisheries Res. and Education Agency, Kamisu-shi, Ibaraki-
ization received pressure levels are corrected for broadband transmission ken,Japan),andIkuoMatsuo(TohokuGakuinUniv.,Sendai-shi,Miyagi-
lossesmodelledusingacalibratedparabolicequationbasedacousticpropa- ken,Japan)
gationmodelforarandomrange-dependentoceanwaveguide.Thebroad-
band vocalization equivalent pulse-compression gains are found to be Passive acoustic monitoring is useful to observe presence of marine
2.561.1forfin,24610forblue,and69623forsei.Thesourceleveldistri- organismssuchasmarinemammals,fishesandcrustaceans.Weaimedto
butionsandpulsecompressiongainsareessentialfordeterminingsignal-to- estimate the distribution of fishes and crustaceans using a towed hydro-
noise ratios and hence detection regions for baleen whale vocalizations phone. A range-wide passive acoustic monitoring was conducted in
received passivelyonunderwateracoustic sensingsystems, aswell as for TateyamabayinJapanusingR/VTakamaru(61t)onJuly,Septemberand
assessing communication ranges and potential for echolocation in baleen Novemberin2015ofdayandnight.Thetowedhydrophone(TowedAqua-
whales. feeler, AquaSound Inc., Japan) was used for the observation. The vessel
cruised 5 knot on 5 lines to cover the focal survey area (N 35(cid:2)020’—N
9:30 35(cid:2)02’ and E 139(cid:2)46—E 139(cid:2)51). Recorded data with frequency from
100 Hz to 20 kHz were analyzed. Recorded fish sounds have dominant
5aAB7.Blind channel estimationof time-varying underwater acoustic
frequencybetween200Hzand1500Hzanddurationbetween0.1sand2.1
waveguide impulse responses. Brendan P. Rideout, Eva-Marie Nosal
s.Crustaceansoundshowsdominantfrequencyas3kHz–20kHzwiththe
(Dept.ofOceanandResourcesEng.,Univ.ofHawaiiatManoa,2540Dole
durationof10ms—20ms.Usingthesefeatures,numberoffishsoundswas
St., Holmes Hall 402, Honolulu, HI 96822, [email protected]), and
counted automatically using custom-made MATLAB program. Large
Anders Host-Madsen (Elec. Eng., Univ. of Hawaii at Manoa, Honolulu,
numberofthesoundswererecordedinthenighttimethaninthedaytime.
HI)
MostfrequentlyreceivedmonthwasJuly.Bothofthefishandcrustacean
Sometechniquesforunderwaterpassiveacousticlocalizationmakeuse soundswereobservedinshallowwater(<30m)showingacousticpresence
ofestimatesforthedirectand/orinterface-reflectedacousticarrivaltimesof map.
3360 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3360
10:30 determinetheorganismcompositionrecordedacousticallyespeciallyinoli-
gotrophic waters where mixed organism assemblages are common. One
5aAB10.Seasonalacousticpresenceoffinandbowheadwhalesinrela-
such mixed stock in the Hawaii Islands is the Deep Scattering Layers
tiontopreyabundanceandoceanographicenvironmentsinthesouth-
(DSL). These layers are made up of micronekton (small squid, fish, and
ern Chukchi Sea. Koki Tsujii, Mayuko Otsuki (Graduate School of
crustaceans) which may be an important component linking primary pro-
Environ.Sci.,HokkaidoUniv.,20-5Benten-cho,Hakodate,Hokkaido040-
ducerswithhighertrophiclevels.Trawlingcanidentifythecompositionin
0051, Japan, [email protected]), Tomonari Akamatsu (National Res.
theselayersbutthistoolcanbecostlyandunabletosampleasmuchareaas
Inst.ofFisheriesSci.,FisheriesRes.Agency,Yokohama,Japan),IkuoMat-
activeacoustics.ManyorganismsintheDSLdiurnallymigratetothesur-
suo(TohokuGakuinUniv.,Sendai,Japan),KazuoAmakasu(TokyoUniv.
face between 0 and 200 m to feed. We surveyed these organisms using
of Marine Sci. and Technol., Konan, Japan), Minoru Kitamura, Takashi
activeacousticsandtrawlingcollectedinJune2013andMarch2014onthe
Kikuchi (Japan Agency for Marine-Earth Sci. and Technol., Yokosuka,
R/VOscarEltonSette.Wecomparedthecompositionoforganisms,volume
Japan),KazushiMiyashita, andYokoMitani(FieldSci.Ctr.forNorthern
byfunctionalgroup,andtotalvolumeinthetrawlwiththeacousticback-
Biosphere,HokkaidoUniv.,Hakodate,Japan)
scattertodeterminetherelationshipbetweentrawlandactiveacousticdata.
Toassesshowseasonalandice-associatedwhalesdifferentlyrespondto Wedeterminedthattheacousticdensitieschangedasafunctionofthetrawl
the Arctic climate changes, understanding the relationships among their compositionandvolumepotentiallyallowingfortheabilitytoexclusively
presenceandenvironmentalconditionsisnecessary.Weexaminedthesea- useacousticsinthefuture.
sonalacousticpresenceoffinBalaenopteraphysalusandbowheadwhales
11:15
Balaenamysticetusinrelationtopreyabundanceandoceanographiccondi-
tionsinthesouthernChukchiSeafromJuly2012toJuly2014usingpassive 5aAB13.Studyingdeepdivingodontocetespotentialpreyfields’densities
andactiveacousticmethods.Oceanographicconditionsobtainedwerewater andsizestructure inHawaiiusingaDIDSONimagingsonar.Giacomo
temperature, salinity and sea ice concentrations. Fin whale calls were GiorliandWhitlowW.Au(HawaiiInst.ofMarineBiology,Univ.ofHawaii
detectedfromsummertofall,onlyinice-freeandhighpreyabundancepe- atManoa,POBOX1306,Kaneohe,HI96744,[email protected])
riod.Moreover,thecall-detectedperiodwaslongerin2013than2012.In
Deepdivingodontocetesodontocetesfeedinthedeepoceanonmesopela-
contrast,bowheadwhalecallsweremainlydetectedfromfalltowinterand
gicsquidandfish.Thedistributionofthesepreyarepoorlyknownbutdoes
inspring,duringice-freeandice-coveredperiods.Thecallpresenceofbow-
affectthedistributionofdeepdivingodontocetepredators.Hence,itisimpor-
headwhalesoverlappedlessfrequentlywiththatoffinwhalesinfall2013
tanttocollectdataonthedensityandcompositionofpotentialpreytoidentify
than2012.Thereasonforthedifferencesintheiracousticpresencebetween
deepseahabitatsthatattractdeepdivingodontocetes.WeusedaDIDSON
thesetwoyearsmaybecausedbyhigherwatertemperatureandlatesea-ice
imagingsonartoinvestigatethedensityandsizestructureofmesopelagicani-
formationin2013comparedtothosein2012.Theseresultssuggestthatan-
malsalongtheKonacoastofHawaii,wherebeaked,spermandpilotwhales
nualvariationsintheoceanographicconditionspossiblyaffectthedistribu-
are regularly seen. Data were collected at multiple stations during three
tionofbothspeciesinthesouthernChukchiSea.
researchcruisesbyloweringthesonarinthewatercolumntosampleatdiffer-
10:45 ent depthsand monitoring the mesopelagic biomasswithan EK6038kHz
echosounder.Foragingactivityofwhaleswasmonitoredatfewstationsusing
5aAB11. Presence of ribbon seal vocalizations are related to sea ice
passiveacousticrecordersandatowedarrayofhydrophones.Wewereable
extentintheNemuroStrait,theOkhotskSea.MayukoOtsuki(Graduate
tocountandsize7068pelagicanimals.Densityandsizevariedinspace,with
SchoolofEnviron.Sci.,HokkaidoUniv.,20-5Benten,Hakodate,Hokkaido
higher densities and bigger animals at the offshore stations. The DIDSON
040-0051, Japan, [email protected]), Tomonari Akamatsu
waseffectiveatdetectingtargetsbiggerthan10cm,asizerangethatincludes
(National Res. Inst. of Fisheries Sci., Japan Fisheries Res. and Education
potentialpreyofdeepdivingodontocetes.Preliminarydatasuggestdifferen-
Agency,Yokohama,Japan),TakahiroNobetsu(ShiretokoNatureFounda-
cesmayexistsinhabitatselectionbyeachdeepdivingodontocetes.
tion, Rausu, Japan), and Yoko Mitani (Field Sci. Ctr. for Northern Bio-
sphere,HokkaidoUniv.,Hakodate,Japan) 11:30
Vocalizations of ice-breeding ribbon seals Histriophoca fasciata were 5aAB14.Snappingshrimp:ChangesinenvironmentalnoiseinLaguna
recordedusingunderwaterpassiveacousticmethodsfromNovember2012 deT(cid:2)erminos,Campeche,M(cid:2)exico,afterhurricanes.CarmenBaz(cid:2)uaDur(cid:2)an
toMarch2014offtheNemuroStrait,Japan.Sealpresenceinthestraitwas (UNAM,FacultaddeCiencias,CircuitoExteriors/n,CiudadUniversitaria,
examinedinrelationtotheseaiceextentintheOkhotskSea.Ribbonseal M(cid:2)exico,D.F.04510,Mexico,[email protected]),PamelaA.AzamarReyes
downsweepswereonlydetectedwhenseaicewaspresentinthestrait(Feb- (FESIztacala,UNAM,Tlalnepantla,Edo.deM(cid:2)exico,Mexico),andWhit-
ruaryandMarch),withmoredetectionsinMarchleadinguptothespring lowW.Au(MMRP,HIMB,Univ.ofHawaii,Kaneohe,HI)
breeding season. Since ribbon seals require ice for breeding, underwater
LagunadeT(cid:2)erminos,Campeche,M(cid:2)exico,isoneofthelargestcoastal
communicationforbreedingcouldbeneededduringtheseaicepresencein
lagoonsinMexicowheresnappingshrimpisthemainsourceofbiological
thisstrait.Northeasterlywindswereanotherindirectdriverofribbonseal
sound.Wemeasuredtheenvironmentalnoisefrom2004to2008instations
occurrence,sincewindsfromthisdirectionlikelytransportseaicefromthe
distributedhomogeneouslyinthislagoonduring17samplingperiodsusing
central Okhotsk Sea into the Nemuro Strait. Downsweep detections
adigitalaudiotaperecordersamplingat48kHzwith16bitsfor1minuteat
decreased in the middle of the day, which is consistent withobservations
eachstation.Theenvironmentalnoiseintherecordingswasmeasuredwith
thatsealshauledoutontheiceduringthistime,andthuswereproducing
asemi-automaticMATLABroutinedesignedforthispurpose.Resultsindi-
fewer underwater vocalizations.Our resultssuggestthat a decreaseinthe
catethatenvironmentalnoiseinthelagoonchangesfromonesamplingto
seaiceextentintheOkhotskSeamaychangethedistributionofribbonseals
another,butitchangeddrasticallyafterthehurricanesof2005insomeof
andimpacttheirbreedingbehavioursincetheNemuroStraitregionofthe
the stations. This changes in submarine environmental noise helps us in
OkhotskSeaislikelythesouthernlimitoftheirbreedingrange.
understandingtheeffectsofnaturalphenomenainthedistributionandabun-
11:00 danceofmarinewildlife,suchassnappingshrimpsandbottlenosedolphins.
M
[WorksupportedbyCONACyT-CampecheandPAPIIT&PASPA-UNAM.]
5aAB12. Comparison between trawl volume and composition and A
acousticbackscatter.AdrienneM.Copeland(Univ.ofHawaiiatManoa, RI.
P.O.Box1346,Kailua,HI96734,[email protected]),WhitlowW.Au F
(HawaiiInst.ofMarineBiology,Kailua,HI),andJeffreyPolovina(PIFSC, a
5
NOAA,Honolulu,HI)
Active acoustics is an important tool to quantitatively assess the den-
sities of pelagic organisms. While it is an important tool, it is hard to
3361 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3361
FRIDAYMORNING,2DECEMBER2016 KAHILI,8:30A.M.TO12:00NOON
Session5aAO
AcousticalOceanography:TopicsinAcousticalOceanographyII
BorisKatsnelson,Cochair
MarineGeosciences,UniversityofHaifa,Mt.Carmel,Haifa31905,Israel
ContributedPapers
8:30 9:00
5aAO1.Effectofsandandsiltparticlesontheattenuationofcompres- 5aAO3. On usingmulti-looksynthetic aperture sonaranalysis for the
sionalwavesinmarinemudsediments.AllanD.Pierce(Retired,POBox investigation of scattering mechanisms. Anthony P. Lyons (Ctr. for
339, 399 Quaker Meeting House Rd., East Sandwich, MA 02537, allan- CoastalandOceanMapping,Univ.ofNewHampshire,UniversityofNew
[email protected]), William L. Siegmann, and Elisabeth Brown(Mathe- Hampshire,Durham,NH03824,[email protected])andDaniel
maticalSci.,RensselaerPolytechnicInst.,Troy,NY) C.Brown(Appl.Res.Lab.,PennStateUniv.,StateCollege,PA)
Mudinmarinesedimentsisamixtureofclay,sand,andsiltparticles. Multi-lookcoherenceexplorestheinformationcontentofsyntheticaper-
Present paper follows up on a suggestion by Holland and Dosso (JASA, turesonar(SAS)imagesbysplittingthetotalangleandfrequencyspectral
2013) that the variability of the measured frequency-dependent compres- bandwidthofacomplexSASimageintosub-bands.Inthepresenceofaran-
sionalwaveattenuationmaybecausedbythevariabilityoftheamountsof domdistributionofsurfaceorvolumescatterers,thespectralcoherenceis
sandandsiltparticles.Thepremiseisthattheporosityforthemudishigh proportionaltothedegreeofoverlapinsub-bandsoftheSASimage.Conse-
andthatthesandandsiltparticlesareinsuspension.Theydonotsettleout quently,foraperfectlyrandomdistributionofscatterers,thespectralcoher-
tothebottomofthelayerbecausethecard-housefabricoftheclayparticles ence should be zero when the sub-bands do not overlap. If the scatterer
tendsto holdthemin place.Thissuppositionleads toa theorywhere the distributiondeviatesfromthisbasicrandomdistribution,thespectralcoher-
clayconfigurationgivesabase-lineattenuation,andthecontributionfrom encemaybenon-zeroforspecialcasesthatwouldberelatedtoscattering
theindividualsandandsiltparticlesisadditive.Theestimationofthelatter fromspecificstructuressuchaspointsorfacets.Forthatreasonitappearsto
isdistinguishedfromtheexistingtheoriesofattenuationofsoundinsandy/ bepossibletoseparatecoherentfeaturesfromtherandomscatteredback-
siltysedimentsinthattheparticlesarepresumednottotoucheachother. groundsignalusingspectralcoherence,suggestingpossibilitiesfordetecting
Particlesareassumedtobesphericalandthereisnoslipbetweenparticle and/orcharacterizingobjects(especiallyinlowsignal-to-reverberationsit-
surfaces and the surrounding water. Earlier theories of attenuation in sus- uations).Inthistalk,wewilldiscusstheconceptandtheutilityofusingthe
pensions by Lamb (Hydrodynamics), Urick (JASA. 1948), and others are complexcoherencebetweenaseriesofsub-lookSASimagestoinvestigate
criticized because of their assumption that vorticity in fluid is zero. The differentscatteringmechanismsaswellasshowexamplesofthetechnique
presenttheorypredictsthattheattenuationcontributionfromagivencate- using real and modeled SAS data. [Work performed under ONR Grants
goryofparticleisproportionaltothesquareofthefrequencyandtosquare N00014-16-1-2469andN00014-16-1-2313.]
ofparticlediameter,andinverselyproportionaltotheviscosity,inthelimit
9:15
of low frequencies. It approaches a frequency-independent constant at
higherfrequencies.[WorksupportedbyONR.] 5aAO4.MultitargetpositioningsystemusingGoldcodepingersapplied
toJapanesesquidinJapanSea.KeiichiUchida(TokyoUniv.ofMarine
8:45
Sci. and Technol., 5-3-6, ko-nan, Minato-ku, Tokyo 108-8477, Japan,
5aAO2.Acousticwavepropagationanalysisfordetectingasensorrobot [email protected]), Toyoki Sasakura (AquaSound, Inc., Tokyo,
in heat transfer pipe. Yoshihiro Nishimura, Yoshinobu Kawagoe, and Japan), Takashi Kamoshida (AquaSound, Inc., Kobe, Japan), Aki Miyagi
YoshihisaHarada(AMRI,AIST,2-1-2,Namiki,Tsukuba,Ibaraki3053564, (AquaSound, Inc., Tokyo, Japan), Yasuo Fujikawa (NICHIA Corp.,
Japan,[email protected]) Yokohama, Japan), Keiichi Kamiya (HAMADE Co., Ltd., Hakodate,
Japan), Hiroshi Inada, and Yoshinori Miyamoto (Tokyo Univ. of Marine
Ultrasonic Testings of heat transfer pipes in electric power plant are
Sci.andTechnol.,Tokyo,Japan)
important.Thosepipes,whichareover60mandwhoseinnerdiametersare
25mm,50mm,and75mm,havemorethan20curvesandarelocatedat To study the effect of light on Japanese squid (Todarodes pacificus)
directlyunaccessibleplace.Wedevelopedacablelessrobotformeasuring behavior, we developed a new ultrasonic biotelemetry system that can
thicknessofpipeinapipefilledwithwaterbutitisdifficulttoknowwhere simultaneouslyobserveandmeasuremultipletargets.Wetestedthesystem
ourrobotisinthepipeatrealtime.Wedevelopedaprojectortopropagate on 40 squids in open water. Each squid was attached with a Gold code
an intensive single-mode wave into the pipes and examined the relations pinger(AquaSoundInc.)thattransmitssinglefrequencysignalsofmultiple
between frequencies-intenseness and wave propagation (3 kHz–50 kHz). codes(IDs).Byusingthecombinationof32kindsofGoldcodesequences,
Attenuationsofacousticwavesinthepipefilledwithwaterweremuchlager wesucceededtodevelopareceivingsystemthatcansimultaneouslytrack
thanthoseinthepiefilledwithairandexaminedformetalpipesandplastic 40pingers.Inthefieldtest,40squidsattachedwiththeGoldcodepingers
pipes.Acousticwavetunnelingthroughpipe-wallwascalculatedandcom- were released simultaneously into open water and signals were recorded
paredwithexperimentalresults.Acousticwavetunnelingthroughthepipe- fromthreefishingboatsforamaximumofsixhours.Theunderwaterposi-
wallwasfoundtobethemainreasonwhyacousticwavecouldnotpropa- tioning of the squids was calculated based on the “reverse cross-bearing”
gatelongerinthepipefiledwithwaterthanthatwithair.Wederiveduseful method by using the cross points from each direction against the target
datatodevelopasystemformeasurementofwhereourrobotis. obtainedbytwoboats.Withtheadditionofdepthdataobtainedbythepres-
suresensorinstalledineachGoldcodepinger,wesucceededtomeasurethe
3Dpositionsofall40targetsquids.Consideringthemovementofboatsby
windandtide,thepositionsofallthreeboatsweremeasuredeverysecond
usingtheGNSS(FURUNOElectronicsCo.,Ltd.).
3362 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3362
9:30 10:30
5aAO5.AcousticcharacterizationofthenewArcticduringIceExercise 5aAO8.Soundintensityfluctuationsasevidenceofmodecouplingdue
2016. John E. Joseph, D. B. Reeder, and Mitchell S. Nelson (Oceanogr., tomovingnonlinearinternalwavesinshallowwater.BorisKatsnelson
Naval Postgrad. School, 833 Dyer Rd., Monterey, CA 93943, jejoseph@ (MarineGeoSci.,Univ.ofHaifa,199AbbaKhouchyAve.,Haifa3498838,
nps.edu) Israel, [email protected]) and Yun Ren (State Key Lab, Inst. of
Acoust.,CAS,Beijing,China)
TheNavalPostgraduateSchool(NPS)participatedinIceExercise2016
(ICEX-16),a multi-national naval exercise conductedinthe BeaufortSea Oneofmanifestationofmodecouplingproducedbymovingnonlinear
duringMarch2016.Operatingataremoteicecamp,NPSdeployedseveral internal(NIW)wavesistemporalfluctuationsofintensityoramplitude.In
conductivity, temperature and depth (CTD) sensors to capture oceano- spectrumoffluctuationsmeasuredduringafewhourstherearemaximums
graphicvariabilityto500mdepthwhileperformingaseriesofpropagation atfrequencies,correspondingtoperiodical(intime)interactionofmoving
tests.Mobileanddippedmid-frequencysourcestransmittedsignalstoapair NIWwithperiodical(inrange)interferencestructureofthesoundfield.If
ofverticallinearrayreceiverspositionedinthefieldtoinvestigatedepth, velocityofNIWalongacoustictrackisv,thenpeaksareplacedatfrequen-
range,angularandspecularcharacteristicsofacousticpropagationandtheir ciesF ~v(k -k ),wherek ispropagationconstantofmodem.Duetoa
mn m n m
correlation to variability in oceanographic structure and under-ice condi- few remaining modes in a long range propagation, spectrum should have
tions.CTDdataindicatetherewassignificantvariabilityinsoundspeedat peaksatafewpredominatingfrequencies.Ingivenworkonthebaseofex-
50mdepthwherecold,freshmixed-layerwaterinterfaceswithcontrasting perimentaldataofASIAEX01andthecorrespondingtheoreticalanalysis,it
warm,salinePacificSummerWater(PSW)thatlaysimmediatelybelowit. isshownexistenceofpredominatingfrequenciesinspectrumofthesound
Thedataalsoshowapersistentandstablesubsurfacesoundchannelexisted intensityfluctuationsinthepresenceofNIWmovingalongacoustictrackof
asaresultofthePSWwithpeaktemperatureat80msituatedabovecolder thelength~35km.BothspeedofNIWandscalesofinterferencebeating
PacificWinterWater(PWW),resultinginasoundchannelaxisnear140m determinementionedfrequencies.Notethatacoustictrackconsistsoftwo
depth.Bothfeatureshaveimportantimplicationsonsonarperformancein partswithdifferentdepths:~250m(NIWaremovingduringtimeinterval
theArctic.Modeledandmeasuredtransmissionlossarecomparedtoquan- considered)and120m(positionofreceivingarray).So,spectrumoffluctua-
tifytheeffects. tions depends on modal structure both parts of this acoustic track. [Work
wassupportedbyISFandNSFC.]
9:45
10:45
5aAO6. Modeling reflection and scattering by deep-ocean turbidites.
DarrellJacksonandDajunTang(Appl.Phys.Lab.,Univ.ofWashington, 5aAO9. Mapping the acoustical properties of the upper sedimentary
1013NE40thSt.,Seattle,WA98105,[email protected]) layerinLakeKinneret.BorisKatsnelson(MarineGeoSci.,Univ.ofHaifa,
Mt.Carmel,Haifa31905,Israel,[email protected]),AndreyLun-
Turbiditesarecommonlyfoundindeepoceansedimentsandarecom-
kov(GeneralPhys.Inst.,RAS,Moscow,RussianFederation),ReginaKats-
posedofmultiplethinlayersoffineandcoarsersediments,thecoarsersedi-
man (Marine GeoSci., Univ. of Haifa, Haifa, Israel), and Ilia Ostrovsky
mentsbeingdepositedbyturbiditycurrents.Althoughacousticsisaunique
(IgalAlonKinneretLab,IOLR,Haifa,Israel)
meanstoquantitativelyprobethephysicalandgeophysicalpropertiesoftur-
bidites,researchonthissubjectisstilllimited.TheworkofGilbertandof Aseriesoffieldexperimentswereconductedtoestimatetheeffective
HollandandMuncillhasshownthatthislayeringcancauseacousticreflec- acousticalpropertiesofthebottominLakeKinneret(Israel).Awideband
tiontobeverystrong,withbottomlosslessthanthatexpectedforhardsea- soundsource(300Hzto2kHz)waspositionedatdifferentranges(1mto6
floors.Weexaminethisproblemfurther,lookingattheeffectoflayeringon km)fromasinglehydrophone.Bothlocalandlong-rangemeasurementsof
penetrationintotheseafloorandalsoconsideringscatteringbyroughnessof thesoundfieldwerecarriedout.Alltheacousticdatademonstratedahigh
theinter-layerinterfaces.Itisfoundthatpenetrationcanbeseverelylimited reflectivityofthelakebottomatallgrazinganglesthatisspecificfeatureof
insomecases,andthatthisbehaviorcanbeunderstoodasaformofAnder- gas-bearingsediments.Experimentalsoundpulseswerecomparedwiththe
son localization. Prospects for inversion of broadband, vertical-incidence simulatedonestoobtainthevaluesofeffectivesoundspeedinthesedimen-
dataareconsidered.[WorksupportedbyONR.] tarylayeratdifferentlocationsinthelake.Usingabasicthreecomponent
sediment’smodel(water,rigidparticles,andgasbubbles),thegasfraction
10:00–10:15Break
inthebottomwasestimated.Ahighcorrelationbetweenthecalculatedgas
fraction and previously measured organic matter concentration was
10:15 observed.[WorkwassupportedbyISF.]
5aAO7. Doppler sonar measurements of bedload sediment transport: 11:00
Yesthere’sasignal,butcanitbequantified?LenZedel(Phys.andPhysi-
cal Oceanogr., MemorialUniv. of NF, Chemistry-Phys. Bldg., St. John’s, 5aAO10. Model-based design of multibeam sonar system. Jun Kuroda
NF A1B 3X7, Canada, [email protected]), Jenna Hare, Alex Hay, and Greg (RadioApplication,GuidanceandElectro-OpticsDiv.,NECCorp.,10,Nis-
Wilson(Oceanogr.,DalhousieUniv.,Halifax,NS,Canada) shincho1-chome,FuchuCity,Tokyo211-8666,Japan,[email protected].
com) and Motohiro Kaname (Maritime Sensor Eng. Div., NEC Network
IthasbeendemonstratedthatDopplersonarmeasurementsofapparent andSensorSystems,Ltd.,FuchuCity,Tokyo,Japan)
bottomvelocityinriversiscorrelatedwithbedloadtransport.Weexplore
thedegreetowhichthismeasurementcanbequantifiedusingafielddeploy- Multibeamsonar is a technique usedto manyapplications in offshore
ablemulti-frequency(1.2-2.2MHz),bistaticDopplersonarsystemthatpro- activities, e.g. oceanographic survey, fish finder and sound navigation in
videsthree-componentvelocityprofilesovera~30cmintervalwith~5mm maritime. Sonar consists of integrated system of components, which are
resolutionatarateof50profiles/sec.Modelsimulationsofsystemperform- acoustictransducers,electricaltransmitterreceivers,andsignalprocessing
ance demonstrate that the estimates of bed movement are proportional to circuits. Numerical prototyping by model-based design (MBD) is widely
sedimentfluxbutscalingtoactualsedimentfluxwouldrequireanempirical employedtodevelopofvariousinstruments,whicharealsousefultodesign M
fit.Inordertoexplorethesystemcapabilityunderactualfieldconditions,a algorithm and configuration of sonar. A sonar system is divided roughly A
s(SerAieFsLo).fTehxepeSrAimFeLntfsacwilaistyupnrdoevritdaeksenaa1t.8thmedSet.epA,n2t.h7o5nmyFwaildlseLflaubmoerattaonryk ianntdoatwcooussytisctefimeldcas,teagnodriecsa,tethgaotryis2t:oeslaeyc,trcicaatelgtoraryns1m:iattceorus,strieccteriavnesrds,ucaenrds RI.
F
thatallowsflowratesoforder1m/soveramobilebedandwherethebed- signalprocessingcircuits.Designofthecategory1needsnumericalsimula- a
loadtransportcanbemeasuredbysedimenttrapsbuiltintotheflumesys- tionofsonicwavesreflectedbytargets.OneissueforMBDistostudya 5
tem.WereportonpreliminaryresultsfromtrialsmadeatSAFL. highspeedandlow-costcomputationmethodtosimulateechosignals.Nu-
mericalcomputationmethods,suchasfinite-elementmethod(FEM),bound-
ary-element method (BEM) and finite-difference-time-domain method
(FDTD),requirelotsofcomputationresourcestosolvelargeacousticfield.
Multibeamsonarisusuallyusedtotargetswhichareawayfromtransducers.
3363 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3363
Therefore,equationstosimulatetransmittedandreceivedsonicwavecanbe demonstrate the potential of sonars for detection and quantification of oil
simplifiedbythefarfieldapproximation.Thispaperproposesanumerical andgasreleasesofnaturaloranthropogenicorigin.Simulationsofacoustic
simulationmethodofacousticechosignalsbetweentransducersandtargets backscatteringfromplumesisanimportanttoolfordesignofleakagedetec-
forMBD. tionsystemsandinsituleakagequantification.Backscatteringfromsubsea
leakagesareoftensimulatedassumingsphericalshapesusing,e.g.,effective
11:15
mediumtheory,howeverinrealworldsituationsbubbleanddropletsarenot
5aAO11.Ultrasoniccharacterizationofseagrassleafblades(Posidonia spherical.Inthisstudythebackscatteringfromsinglebubbles(CO2,CH4,
oceanica).JayR.Johnson,GabrielR.Venegas,PrestonS.Wilson(Mech. and air) and droplets (light and heavy oil) are simulated under different
Eng., The Univ. of Texas at Austin, 1 University Station, C2200,Austin, shape regimes (i.e. as a function of Reynolds and E€otv€os number). The
TX 78712, [email protected]), Jean-Pierre Hermand (LISA shapes are extracted from time dependent Computational Fluid Dynamics
Environ.HydroAcoust.Lab,Universit(cid:2)elibredeBruxelles(ULB),Brussels, simulationsandthebackscatteringismodeledusingadaptivecrossapproxi-
BrusselsCapital,Belgium),andThibaultUrban(NDTDept.,Vinc¸otte,Vil- mationacceleratedBoundaryElementMethod(BEM).Thebackscattering
voorde,Belgium) from single bubbles and droplets are used as input to effective medium
theorysimulationsofplumes.SimulationsusingBEMandeffectivemedium
Ithasbeenshownthatsimplemixturetheorymodelsareinadequateto theorywithsphericalandnon-sphericalbubblesanddropletsarecompared
describe low-frequencysound propagation throughseagrassmeadowsand with controlled in situ measurements of backscattering with concurrent
furtherunderstandingoftheacousticpropertiesofseagrasstissueisneces- shapemeasurements.
sary.Tothatend,wepresenttwoultrasonicsoundspeedmeasurementson
the Mediterranean seagrass Posidonia oceanica. First, a transit time mea-
11:45
surementthroughastackof120leafbladesat2.25MHzarecomparedto
similarmeasurementsmadeonmacroalgaeEckloniaradiata.Soundspeed 5aAO13.Determinationofacousticwaveguideinvariantusingshipsas
differencesarerelatedtothegascontentwithintheaerenchymaofseagrass sourcesofopportunityinashallowwatermarineenvironment.Christo-
and other tissue characteristics. Second, ultrasonic sound speed measure- pher M. Verlinden, Jit Sarkar (Marine Physical Lab., Scripps Inst. of
mentsthroughasuspensionoffinelydividedP.oceanicaleafbladesatfre- Oceanogr.,Univ.ofCalifornia,SanDiego,9500GilmanDr.,LaJolla,CA
quenciesbetween1and4MHzarecomparedtolow-frequency(1-8kHz) 92093-0701,[email protected]),BruceCornuelle,andWilliamA.Kuper-
sound speed obtained on the same blade suspension by means of a reso- man(MarinePhysicalLab.,ScrippsInst.ofOceanogr.,Univ.ofCalifornia,
nancechamber. SanDiego,SanDiego,CA)
11:30 Thewaveguideinvariant(WGI)isapropertythatcanbeusedtolocalize
acousticradiatorsandextractinformationabouttheenvironment.Here,the
5aAO12.Simulationofacousticbackscatteringfrombubblesanddrop-
WGIisdeterminedusingshipsassourcesofopportunity,trackedusingthe
lets under different shape regimes with implications for underwater
Automatic Identification System (AIS). Using a single hydrophone the
detectionofleakagesusingactiveacousticsensors.GeirPedersen(Instru-
acoustic intensity as a function of range and angle is measured in the
mentation,ChristianMichelsenRes.AS,P.O.Box6031,Bergen5892,Nor-
presenceofshipsatavarietyofrangesandangles.Therelationshipbetween
way,[email protected])
range,intensity,andfrequencyisusedtodeterminetheWGIparameterb
Safesubseaproductionofoilandgas,aswellasstorageofCO ingeo- forshipsinavarietyofpositions.TheseBetavaluesareinterpolatedanda
2
logical formations subsea, require rapid detection of accidental releases, mapofbiscreatedfortheenvironmentinquestion.Themethodisdemon-
eliminating potential harm to the environment. Monitoring of natural gas strated using data collected on a single hydrophone in a shallow water
seepsareimportantinaclimateandenvironmentalaspect.Previousstudies environmentoffthecoastofSouthernCalifornia.
3364 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3364
FRIDAYMORNING,2DECEMBER2016 CORAL1,8:00A.M.TO10:00A.M.
Session5aBAa
BiomedicalAcoustics:AcousticsforOlderPersonswithDisabilities
TakayukiArai,Cochair
InformationandCommunicationSciences,SophiaUniversity,7-1Kioi-cho,Chiyoda-ku,Tokyo102-8554,Japan
MariUeda,Cochair
DepartmentofDesignStrategy,KyushuUniversity,4-9-1Shiobaru,Fukuoka815-8540,Japan
InvitedPapers
8:00
5aBAa1.Theactivitiesoftheresearchcommitteeon“Otobarrier-free”oftheAcousticalSocietyofJapan.KimioShiraishi(Fac-
ultyofDesign,KyushuUniv.,4-9-1Shiobaru,Minami-ku,Fukuoka815-8540,Japan,[email protected]),KentaroNaka-
mura(Inst. ofInnovativeRes., TokyoInst.of Technol.,Tokyo,Japan),YasuhiroOikawa (Facultyof Sci. andEng.,Waseda Univ.,
Tokyo,Japan),andMariUeda(FacultyofDesign,KyushuUniv.,Fukuoka,Japan)
Thenumberofthepersonsabove65yearsoldhasreached26%ofthepopulationinJapan.Consequently,thenumberofpersons
withhearingand/orvisualimpairmentshasincreasedveryrapidly.Itisimportanttosupportcommunicationorsoundinformationcom-
pensationforthesepersons.Fromthisbackground,theresearchcommitteeon“Otobarrier-free”oftheAcousticalSocietyofJapanhas
startedin2006.The“Otobarrier-free”committeeintendstoresolveproblemsrelatedtoimprovingaccessibilityindailylifeforpersons
withdisabilitiesorelderlypeople.Theresearchfieldsareverydiverseandincludespeechcommunication,electro-acoustics,noiseand
vibration,architecturalacoustics,andlawsfordisabledpersons.Theresearchactivitiesforpersonswithhearingimpairmentsorelderly
peopleaimtoimprovetheirlisteningenvironmentinindoorspaces,suchashomesfortheagedorstationbuildings,bytestingtheuseof
soundabsorbingmaterialsandhearingassistivedevices.Theresearchassistsorcomplementstheuseofaidssuchasvoiceguidance
devicesforpersonswithavisualimpairment,andwillbeusefulforforeignersvisitingtheTokyoOlympicsandParalympicsGamesin
2020too.
8:20
5aBAa2.Relationshipbetweenauditorydegradationandfricatives/affricatesproductionandperceptioninelderlylisteners.Keii-
chiYasu(NationalRehabilitationCtr.forPersonswithDisabilities,1,Namiki4-chome,Tokorozawa359-8555,Japan,keiichi.yasu@
gmail.com),TakayukiArai(SophiaUniv.,Tokyo,Japan),KeiKobayashi(TheUniv.ofAuckland,Auckland,NewZealand),andMit-
sukoShindo(SophiaUniv.,Tokyo,Japan)
Elderlypeopleoftencomplainthattheystrugglewithconsonantidentificationwhenlisteningtospokenlanguage.Inpreviousstud-
ies,weconductedseveralexperiments,includingidentificationtestsforyoungandelderlylistenersusing/shi/-/chi/(CV)and/ishi/-/
ichi/ (VCV) continua. We also recorded production of such CV and VCV syllables. For the CV stimuli, confusion of /shi/ as /chi/
increasedwhenthefricationhadalongrisetime.Thedegreeofconfusionincreasedwhenauditorypropertydegradationwasobserved
suchasthresholdelevationinhighfrequency.IntheVCVstimuli,confusionof/ichi/as/ishi/occurredforalongsilentintervalbetween
thefirstVandCwithauditorypropertydegradation.Inthepresentstudy,weanalyzedtheutterancesofthoseCVandVCVsyllables
andmeasuredthedurationoffricationandsilentinterval.Thedirectionoftheboundaryshiftintheperceptionoffricativesandaffricates
byauditorydegradationwasconsistentwiththatofproduction.Wefoundthatdegradationofauditorypropertiesaffectsbothperception
andproductionoffricativesandaffricatesinelderlypeople.
8:40
5aBAa3.AspeechsynthesizerofJapanesesavespatients’voices.TakayukiArai(SophiaUniv.,7-1Kioi-cho,Chiyoda-ku,Tokyo
102-8554, Japan, [email protected]), Shigeto Kawahara (The Keio Inst. of Culture and Linguistic Studies, Tokyo, Japan), Musashi
Homma(TokyoMetropolitanNeurologicalHospital,Tokyo,Japan),andTakakiYoshimura(Pasobora,Sasebo,Japan)
M
“MyVoice,”freespeechsynthesissoftwareforJapanese,developedbyoneoftheauthors,iswidelyusedtosavemanypatients’voi-
A
cesinJapan.Weloseourvoiceforvariousreasons.AmyotrophicLateralSclerosis,orALS,isanexample.WhenanALSpatienthas
difficultybreathing,Tracheotomybecomesanoption,andthepatientlosestheabilitytospeak.Laryngectomyisanotherexample.By RI.
using“MyVoice,”patientscankeepcommunicatingusingtheirownvoiceevenafterlosingthatability.Tofacilitatethis,patientsrecord F
utteranceswiththeirvoicebeforesurgery.Therecordingisdesignedtominimizetimeandloadofpatientsasmuchaspossible,by a
5
includingJapanesebasicmorasetsothatpotentiallyanywordcanbeconcatenatedfromtherecordedsounds.Thegraphicaluserinter-
faceofthissoftwareiswell-designedsothattherapistsaswellasthepatients’familyandfriendscanalsouseitwithaminimumof
effort.Infact,weoftenhearheart-warmingstoriesofmaking“MyVoice.”“MyVoice”continuestorescuepatients’voicesandwewill
continuemakingimprovementstoitinthefuture.
3365 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3365
9:00
5aBAa4.Audioserviceforelderlypeopleinbroadcasting.TomoyasuKomori,TakehiroSugimoro,andAtsushiImai(Sci.&Technol.
Res.Labs.,NHK(Japanbroadcastingcorporation),1-10-11KinutaSetagaya-ku,Tokyo1578510,Japan,[email protected])
Elderlyviewerssometimesfeelthatthebackgroundsound(musicandsoundeffects)intelevisionprogramsistooloudorthatthe
narrationorspeechistoofasttounderstand.Weattemptedtosolvetheseproblemsbytwomethods:improvementofthereceiversystem
andthedevelopmentofanewbroadcastingsystem.Weprototypedareceiversysteminwhichloudnessbalancebetweenthedialog(nar-
rationorspeech)andbackgroundsoundcanbeadjusted,aswellasthespeechrate.Theresultsofsubjectiveevaluationexperiments
withelderlyviewersshowedthattheuseofthissystemcouldsignificantlyfacilitatelisteningtotelevisionsound.In2016,westarted
testbroadcastingof8KSuperHi-Vision(8KSHV)programsthathavehighlyimmersivesurroundsoundproducedthrough22.2multi-
channel(22.2ch).Withtheaimofimprovingthefunctionalityof8KSHVsoundasabroadcastingservice,adomesticstandardhasbeen
establishedforthedialoguecontrolfunctions,includingthedialogenhancementandadialogreplacementfunction.Inthispresentation,
weshowthesetwotypesofaudioserviceforelderlypeople.
9:20
5aBAa5.Useofdatahidinginaerialsoundsforaccessibility.AkiraNishimura(Dept.ofInformatics,TokyoUniv.ofInformation
Sci.,4-1,Onaridai,Wakaba-ku,Chiba2658501,Japan,[email protected])
Thisarticlereviewsprevioustechnologiesforaerialacousticdatatransmission,namely,audiodatahiding,acousticmodems,anda
hybridofthetwo.Thesetechnologiescanprovideaninformationchanneltoconveyindexdataforstatictextmessagesordatafortext
messagestoassistpeoplewhoaredeaforhardofhearing.Thepayloadbitrateofthesetechnologiesrangesfromseveralbitspersecond
forlongdistances(>100m)tohundredsofbitspersecondforshortdistances(<1m).Previousstudieshavemainlyfocusedondevelop-
ingmethodsforembeddingandencodinginformationintoaerialsounds.However,fewworkshaveevaluatedactualaerialtransmission
inthepresenceofvariousdisturbances,suchasreverberationandreflections,transferfunctionsofloudspeakersandmicrophones,non-
lineardistortionsinloudspeakers,backgroundnoise,andDopplereffects.Therefore,inthisstudy,evaluationmethodsfortheseacoustic
datatransmissiontechnologiesareproposedanddiscussed.Inaddition,practicalapplicationsarediscussedregardingtheuseofthetech-
nologiesasameansofaccessibilityforpeoplewithspeechandlanguagedisabilities.
9:40
5aBAa6.AcousessMap:Smartphone-basedcollaborativetooltofacilitateassessingacousticalaccessibilityconditionsforvisually
impaired people. Mari Ueda (Dept. of Design Strategy, Kyushu Univ., 4-9-1 Shiobaru, Fukuoka, Minami-ku 815-8540, Japan, m-
[email protected]),TakahiroMiura,Ken-ichiroYabu(Univ.Tokyo,Tokyo,Japan),TakashiMorihara(INCT,Kanazawa,Ja-
pan),andYoshioTsuchida(KIT,Kanazawa,Japan)
Assistiveinstrumentssuchastexturedpavingblocksandacousticaltrafficsignalsareinstalledforhelpingvisuallyimpairedpeople
towalkcomfortablyandavoidtrafficaccidents,whohaveanyinconveniencetomoveoutside.Thoughtheseprecipitoussituationsof
accessibilityprogressaffecttheirmigrationpathwayfortheirdestination,up-to-dateaccessibilityinformationisdifficulttogainquickly
becauseoflocalinformationdisclosure.Thusitisnecessarytodevelopacomprehensivesystemthatappropriatelyacquiresandarranges
scatteredaccessibilityinformation,andthenpresentsthisinformationintuitively.However,thesesystemspresentvolunteerswithdiffi-
cultieswhentheyaregatheringaccessibilityconditionsandthenorganizingthem.Also,mostofthevolunteersdonotknowthecurrent
situationsofacousticalsupportsystemsforthevisuallyimpaired.Inthisstudy,ourfinalgoalistoestablishanefficientschemetoshare
theconditionsandplacesoftheacousticalsupportsystemsbymanyvolunteers.Particularly,inthisreport,weaimedtocheckthefeasi-
bilitytosharetheacousticalconditionstothewebbypersonswithoutanyknowledgeofthesupportsystems.Wefirstdevelopeda
smartphone-basedapplicationforsharingaccessibilityconditionsandcarriedouteventstoshareaccessibilityconditionsasapartofa
lecturecoursefortechnicalcollegestudents.
3366 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3366
FRIDAYMORNING,2DECEMBER2016 CORAL3,8:00A.M.TO12:00NOON
Session5aBAb
BiomedicalAcoustics:BiomedicalAcousticsPosterSession
KangKim,Chair
Medicine,UniversityofPittsburgh,950ScaifeHall,3550TerraceStreet,Pittsburgh,PA15261
Allposterswillbeondisplayfrom8:00a.m.to12:00noon.Toallowcontributorsinthissessiontoseetheotherposters,authorsofodd-
numberedpaperswillbeattheirpostersfrom8:00a.m.to10:00a.m.andauthorsofeven-numberedpaperswillbeattheirpostersfrom
10:00a.m.to12:00noon.
ContributedPapers
5aBAb1. Tissue boundary roughness index for evaluating malignancy 5aBAb3. Relative impedance variation based temperature monitoring
ofcancerinultrasound-computedtomographysystem.KazuhiroYama- anddosecontrolforhighintensityfocusedultrasoundtherapy.Qingyu
naka,TakahideTerada,YushiTsubota,WenjingWu,AtsuroSuzuki,Taka- Ma, Gepu Guo (School of Phys. andTechnol., Nanjing Normal Univ., 1
shiMaruoka,andKen-ichiKawabata(Res.&DevelopmentGroup,Hitachi, Wenyuan Rd., Nanjing, Jiangsu 210023, China, [email protected]),
Ltd.,1-280,Higashi-Koigakubo,Kokubinji,Tokyo185-8601,Japan,kazu- Juan Tu, Dong Zhang (Inst. of Acoust., Nanjing Univ., Nanjing, Jiangsu,
[email protected]) China),andShaotongFeng(SchoolofPhys.andTechnol.,NanjingNormal
Univ.,Nanjing,Jiangsu,China)
Ultrasound-computedtomography(USCT)isapromisingcandidatefor
aradiationfree,painless,andquantitativemodalityforbreastcancerexami- Highintensityfocusedultrasound(HIFU)canbeusedasanon-invasive
nation. We developed a USCT prototype with a ring-shaped transducer andefficienttherapyapproachtotreattumorsbyheatcoagulationwithless
array(frequency:1.5MHz)thatmovesalongtheringaxisforscanningthe metastasis,althoughitisstilllimitedbyinaccuratetemperaturemonitoring
entirebreast.Distributionsofspeedandattenuationofultrasoundarecom- andefficacyevaluation.Basedontherelationshipbetweentemperatureand
puted from ultrasoundtransmittedthroughtissue. Although prior research electrical impedance, a model of impedance measurement during HIFU
showsthatthereisacorrelationbetweenmalignancyandthespeedofsound therapywasestablished.Numericalstudiesonthedistributionsofacoustic
and attenuation values, in some cases both benign and malignant tumors pressure,temperatureandconductivityweresimulated,andtheimpedances
have similar values. In this study, we propose to quantify the boundary inthemodelwerecalculatedwiththeelectricalpotentialandcurrentden-
roughnessofatumorfromthespatialpowerdistributionsofreflectedultra- sity.Itisprovedthat,forafixedacousticpowerinthefocalregion,therela-
soundsthataretransmittedfromdifferentaperturesoftheringtransducer. tive impedance variation (RIV) linearly increases with the increasing
Inconventionalultrasoundechography,theboundaryroughnessofatumor treatmenttimeandisinverselyproportionaltoacousticpower,whiletherel-
isanimportantindicatorofmalignancy.However,roughnessisjudgedby ativeimpedancevariationrate(RIVR)showsalinearrelationshipwiththe
radiologistsbasedonB-modeimagesandisasubjectiveindex.Wesimu- acousticpower.Thetreatmenttimethatisrequiredforthetemperaturein
latedtheultrasoundreflectionsignalfromboundariesofdifferentroughness. thefocalregiontoreach70degreeisinverselyproportionaltothesquareof
Thesimulationresultindicatesthataspatialpowerconcentrationhasasig- acousticpower.TheexperimentalresultsofRIVandRIVRmeasuredatdif-
nificant correlation with boundary roughness. We confirmed through gel ferent powersandtreatment times arein goodagreementswiththe simu-
phantomexperimentsthattheindexdistinguishesroughandsmoothboun- lateddata.TheresultssuggestthattheRIVcanbeusedasausefulindicator
daries,whichisnotevidentinB-modeimages. for the non-invasive temperature monitoring and efficacy evaluation, and
mightprovidenewstrategyforaccuratedosecontrolofHIFUtherapy.
5aBAb2. Tissue lesion formation induced by high intensity focused
ultrasoundalongaspiralpathway.DongZhang,JuanTu,XiashengGuo 5aBAb4. A high-frequency ultrasound method for testing skin cancer
(Phys., Inst. of Acoust., Nanjing Univ, 22 Hankou Rd., Nanjing 210093, marginsexvivo.ZacharyA.Coffman(Biology,UtahValleyUniv.,2750
China, [email protected]), Qingyu Ma, and Gepu Guo (Phys., Nanjing W. Spaulding Ln., West Jordan, UT 84088, zachary.a.coffman@gmail.
NormalUniv,Nanjing,China) com),CaitlinCarter(BioTechnol.,UtahValleyUniv.,Orem,UT),DollyA.
Sanjinez(Biology,UtahValleyUniv.,Orem,UT),GarrettWagner(Com-
Boththeoreticalandexperimentalstudieswereperformedheretoinves- put. Eng.,UtahValleyUniv.,Orem, UT),RobynK.Omer(Botany,Utah
tigate the lesion formation induced by high-intensity focused ultrasound ValleyUniv.,Orem,UT),andTimothyE.Doyle(Phys.,UtahValleyUniv.,
(HIFU)operatingincontinuousscanningmodealongaspiralpathway.The Orem,UT)
Khokhlov-Zabolotskaya-Kuznetsov equation and bio-heat equation were
combinedinthecurrentmodeltopredictHIFU-inducedtemperaturedistri- Mohssurgeryisthestandardsurgicaltreatmentforbasalcellcarcinoma
bution andlesion formation. Theshape of lesion andtreatment efficiency andseveralmelanomas.Itinvolvesresectingsuccessivelayersoftheskin
wereassessedfora givenscanningspeedattwodifferentgridspacing(3 cancerandsurroundingtissue(margins),analyzingthetissueinapathology M
mm and 4 mm) in both the gel phantom and ex vivo studies. The results laboratory,andusingtheresultstodeterminewhetherallofthecancerhas A
showthatuniformlesionscanbegeneratedbythehomogenizationofther- been removed or whether another layer needs to be resected. Although RI.
maldiffusionalongthespiralscanningpathway.Thecompletecoverageof resectionofeachlayeronlytakes5-10minutes,proceduretimesforMohs F
theentiretreatedvolumecanbeachievedaslongasthespacinggridofthe surgeryareapproximately4hourssincethepathologyanalysisisverytime a
5
spiralpathwayissmallerthanacriticalvaluethatrightmatchesthemaxi- consuming.Arapidspecimenassessmenttechniquefordetectingskincan-
mumthermaldiffusiondimension,andthetreatmentefficiencycanbeopti- cerinsurgicalmarginswouldthereforebeofsignificantbenefittodermatol-
mizedbyselectinganappropriatescanningspeed.Thisstudycanprovide ogy surgeons and their patients. A high-frequency ultrasound method has
guidance for further optimization of the treatment efficiency of HIFU beendevelopedtotestMohssurgicalspecimenswithouttheneedfordirect
therapy. immersionortransducercontactonthespecimens.Theultrasoundsystem
3367 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3367
uses a 50-MHz, narrow-beam (1.5 mm) pachymeter probe; a 50-MHz, 5aBAb7. Modular arrays for transpinal ultrasound application. Shan
broad-beam (6.25 mm) transducer; a high-frequency pulser-receiver; a 1- Qiao,ConstantinCoussios,andRobinCleveland(Dept.ofEng.Sci.,Uni-
GHzdigitaloscilloscope;andanaluminumteststagetoholdandscanthe versity of Oxford, Inst. of Biomedical Eng., Old Rd. Campus Res. Bldg.,
specimen. Pitch-catch and pulse-echo measurements are collected from Headington, Oxford, Oxford OX3 7DQ, United Kingdom, shan.qiao03@
eachtestpositiononthespecimentodeterminetheposition’sthicknessand gmail.com)
ultrasonic wave speed. Other parameters calculated from the data include
Lowerbackpainisoneofthemostcommonhealthproblemsindevel-
attenuationandspectralpeakdensity.
opedcountries,andisnormallycausedbythedegenerationofintervertebral
discs.Highintensityfocusedultrasoundcanbeusedtomechanicallyfrac-
5aBAb5. Transducer influence on magnetoacoustic tomography with tionatedegeneratedisctissuebyinertialcavitation.Duetothecomplexity
magneticinductionbasedon3Dequivalentsourceanalysisfortissues. of thespine structure,delivering sufficientfocusedacoustic energy to the
QingyuMa,ShaotongFeng,GepuGuo(SchoolofPhys.andTechnol.,Nanj- targetzonewithoutdamagingsurroundingtissueischallengingandfurther
ingNormalUniv.,1WenyuanRd.,QixiaDistrict,Nanjing,Jiangsu210023, exacerbatedbypatient-to-patientvariability.Hereweproposethedesignof
China,[email protected]),JuanTu,andDongZhang(Inst.ofAcoust., modulararrays,eachconsistingof32elementsat0.5MHz,whichcanbe
NanjingUniv.,Nanjing,Jiangsu,China) configuredtooptimizedeliveryforaspecificpatientbythemeansoftime-
reversalusingthepatientgeometryderivedfromCTscans.Initialtestswere
Asanoninvasiveimagingmodalitybasedonthecouplingofmagnetic
carried out in water and compared with simulations. Using four different
and acoustic fields, magnetoacoustic tomographywith magnetic induction
configurationsoffourmodules,focusingwasaccomplishedusinganeedle
(MAT-MI)hasbeendemonstratedtohavethecapabilityofimagingthevar-
hydrophoneatthetargetlocationtodeterminethetransmitphaseforeach
iationofconductivitydistributioninsidetheobject.However,theimagere-
element.Ineachofthefourconfigurationsafocalgainofapproximately35
solution is still limited by the parameters of the receiver. Based on the
wasachievedandsteeringrangeofthefocuswas+/-30mminazimuth,+/-
theoryofacousticdipole,3Dequivalentsourceanalysiswasusedtosimu-
5mminelevation.Theseresultsconfirmthatthenumericalmodelaccurately
latetransducerdetectedpressuresandwaveformsforMAT-MI.Theinflu-
predictstheacousticfieldofthemodulararrayandcanbeusedfortreatment
enceoftransducerwasstudiedboththeoreticallyandexperimentallyfora
planninginadisc.[WorksupportedbyEPSRC,UK.]
cylindricalmodel.Itisdemonstratedthatlarge-radiustransducerwithstrong
receptionpatterncandetecttheacousticsignalstransmittedalongitsnormal
directionwithsharppressurepeaks,reflectingthedivergenceoftheinduced 5aBAb8.Dynamicsofanacousticallydrivenliquid-gasinterface.Bran-
Lorentzforce.Byconsideringtheeffectofacousticattenuationandtheac- donPattersonandEricJohnsen(Univ.ofMichigan,1231BealAve.,Rm.
curacyofimagereconstruction,theacousticpressurewithacceptablepeak 2016,AnnArbor,MI48109,[email protected])
pressureratio andimprovedSNRcan bedetectedwhenthe scanning dis-
Interactionsbetweenacousticwavesandliquid-gasinterfacesoccurina
tance is 5-10 times the radius of the object. Wide bandwidth transducer
variety of applications, including diagnostic ultrasound of the lung. We
shouldalsobeselectedtoreducetheboundarywidthofborderlinestripes
hypothesizethat,becauseofthesharpdensitygradientatthefluiddisconti-
andimprovethespatialresolutionofreconstructedimages.Thefavorable
nuity,acousticwavesmaygeneratesufficientbaroclinicvorticitytoappreci-
resultsconfirmtheinfluenceoftransduceronMAT-MIandalsoprovidethe
ablydeformliquid-gasinterfaces.Thisnonlineareffecthasbeenstudiedfor
fundamentalsfortransducerselectioninfurtherstudytoimprovetheaccu-
shock-accelerated interfaces, i.e., the Rictmyer-Meshkov instability; how-
racyofelectricalimpedancereconstruction.
ever,itisnotdescribablethroughtraditional,linearacousticmethodsandis
notwellstudiedforacousticwaves.Toinvestigateourhypothesis,wesimu-
5aBAb6. Optimization of sphingosylphosphorylcholine concentration lateaninviscid,compressiblefluidsystemwithacousticwavesimpinging
fordetectionofcytoskeletalchangesinmalignantpancreaticcellsusing fromwaterintoair.Wefindthatacousticwavescapableofdeformingthe
high-frequency ultrasound. Caitlin Carter (BioTechnol., Utah Valley interface during the wave-interface interaction period will deposit lasting
Univ.,886E.OldEnglishRd.,Draper,UT84020,caitlin.carter03@gmail. baroclinicvorticityalongtheinterface,capableofdrivingdeformationthat
com),DollySanjinez(Biology,UtahValleyUniv.,Orem,UT),MandyMar- continueslongafterthepassageofthewave.Weusedimensionalanalysis
vel (BioTechnol., Utah Valley Univ., Orem, UT), and Timothy E. Doyle todescribethedependenceofthelate-timeinterfacegrowthonthedepos-
(Phys.,UtahValleyUniv.,Orem,UT) itedvorticity.Lastly,weshowresultstodemonstratethatforacousticwaves
with properties relevant to diagnostic ultrasound encountering a water-air
Thebiomechanicalpropertiesofcellscanbegreatlyinfluencedbymod-
interface,nearlyallofthevorticityisgeneratedingas-dominatedfluid.We
ificationsofthecytoskeletonofthecell.Cytoskeletalmodificationscanof-
explainthisusinganorderofmagnitudeanalysis.
tenbelinkedtodiseaseanddiseasepathways.Cancermetastasishasbeen
previously associated with the cytoskeletal modifications that are induced
bytheadditionofsphingosylphosphorylcholine(SPC)topanc-1cells.SPC 5aBAb9. Parametric array for tissue harmonic imaging. Christina P.
isabioactivelipidthatreorganizeskeratinfilamentsinthecytoskeletoninto KeravnouandMichalakisA.Averkiou(BioEng.,Univ.ofWashington,Wil-
aperinuclearshapethatenablescellmobility.ThemaximumeffectofSPC liamH.FoegeBldg.,372015thAve.NE,Seattle,WA98195,maverk@uw.
onthekeratinreorganizationhasbeenpreviouslyobservedasbeingconcen- edu)
tration dependent, with 5-10lM concentration being optimal as observed
Morethan50%ofabdominalscansareperformedontechnicallydiffi-
through keratin immunostaining. In this work, high frequency ultrasound
cultpatientsduetoworldwideincreaseofobesity.Tissueharmonicimaging
was used to observe the SPC induced keratin reorganization through an
hasshownsomeimprovementsonobesepatientsbuttheproblemremains
ultrasoundsignature.Ultrasoundmeasurementswereobtainedusing10lM
unsolved. The use of dual frequency pulses allows the generation of sum
SPCand~17lMSPCconcentrations.Significanttime-dependentchangesin
anddifferencefrequenciesintissue.Wehypothesizethatthedifferencefre-
theultrasoundmeasurementswereobservedinthehigherconcentrationof
quency (Df, parametric array) can survive larger penetration depths and
SPCascomparedtocontrolcellculturesthatwerenottreatedwithSPC.In
increase SNR while maintaining the spatial characteristics of the primary
contrast,thelowerconcentrationofSPCdidnotshowvisiblechangesinthe
wave.Ourobjectivewastooptimizetheparametersforefficientgeneration
ultrasoundmeasurementstaken.Futureworkwillincludeoptimizingamore
oftheparametricarrayandstudyitsspatialcharacteristicsforimagingobese
specificconcentrationofSPCforobservingchangesintheultrasoundmeas-
patients.NumericalsimulationsusingKZKequationandmeasurementsin
urementstakenofpanc-1cells.
tissue-like media were performed to study parametric arrays. Pulses with
twofrequencies(f,f)wereconsideredwhere0.1f(cid:3)Df(cid:3)f.Pulseinversion
1 2 1 1
wasutilizedtoisolate evenharmonics,includingDf.TheamplitudeofDf
wasmaximizedatDf=f.Theaxialresolutionisnotseriouslycompromised
1
bythelowerfrequencyofDfwhenusingPI.For0.5dB/cmattenuationdif-
ferencebetweenDfand2f1,Dfechoesfrom20cmdeepweregreaterby10
dB. Application of the parametric array on larger technically difficult
patientswouldoffersimilarbenefitsasthoseinsonarapplications.
3368 J.Acoust.Soc.Am.,Vol.140,No.4,Pt.2,October2016 5thJointMeetingASA/ASJ 3368