Stage Acoustics for Symphony Orchestras in Concert Halls

211 Pages·2010·2.77 MB·English

by  Jens Jørgen Dammerud

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PRESENTS

The PhD thesis by Jens Jørgen Dammerud:
Stage Acoustics for Symphony Orchestras in Concert Halls
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Stage Acoustics
Concert Hall Acoustics
STAGE ACOUSTICS FOR SYMPHONY
ORCHESTRAS IN CONCERT HALLS
Submitted by Jens Jørgen Dammerud
for the degree of
Doctor of Philosophy
of the University of Bath
September 2009
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This thesis may be made available for consultation within the University library and may be
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Acknowledgments
Iwouldliketothankeveryonewhohasgenerouslycontributedtotheworkformingthisthesis:
First of all the musicians of professional symphony orchestras who have taken part in
discussions(inalphabeticalorder): DavidDaly,ChrisGale,GunnarIhlen,KevinMorgan,Finn
Orestad, Torbjørn Ottersen, Mike Smith, Geir Solum and Bengt A˚rstad. I would also like to
thank all the musicians who responded to questionnaires, the contact persons within all the
symphonyorchestraswhokindlycollaboratedinthisprojectandmywifeSilje MarieSkeiefor
allusefulinputasamusician.
Peoplefromwithinthedisciplinesofacoustics,audioandsciencewhohavesharedtheirown
resultsandgivenvaluableinputtothisresearch(inalphabeticalorder): NielsWernerAdelman-
Larsen,JohanAndersson,PeterD’Antonio,SteveBarbar,AlfBerntson,BertievandenBraak,
Anders Buen, Eddy Bøgh Brixen, Stephen Chiles, Bengt-Inge Dalenba¨ck, Anders Christian
Gade, Maria Giovannini, David Griesinger, Tor Halmrast, Masahiro Ikeda, Eckhard Kahle,
John O’Keefe, Asbjørn Krokstad, Russell Mason, Bob McCarthy, Ju¨rgen Meyer, Geoff Miles,
EckardMommertz,LarsHenrikMorset,FrancisRumsey,AnssiRuusuvuori,MagneSka˚levik,
Olav Skutlaberg, Audun Strype, Peter Svensson, Kanako Ueno, Ian Walker and members of
theSyn-Aud-ConforumandtheAUDITORYlist.
Allfellowplayerswhohavetoleratedthesqueaksfrommyclarinetsandsaxophones,allowing
metogetvaluableexperienceonhowitistoplaywithinacousticensemblesoverthelastfive
years: NordreAkerJanitsjar (Oslo),Wind Band andUniversityOrchestra(UniversityofBath)
and Bath All Comers Orchestra. Also a big thank you to all fellow postgraduates, academic
andsupportstaffattheUniversityofBathandthepeopleatBrekke&Strandakustikk.
I am also very thankful to Eckhard Kahle, Andy Shea, Bengt-Inge Dalenba¨ck, Gunnar Ihlen
andMagneSka˚levikforprovidingvaluablecommentsonpreliminaryversionsofthethesis.
Lastbutnotleast,IammostgratefultomysupervisorMikeBarronforinvitingmetotakepart
in this project and for generously sharing his knowledge and guiding me towards completion
ofthisthesis–andmywifeandsonforallsupportandinspiration.
TheresearchprojectonwhichthisthesisisbasedwasfundedbytheEngineeringandPhysical
SciencesResearchCouncil(EPSRC),UK.
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Abstract
The main goals for this study were to better understand what are the acoustic conditions
physicallywithin asymphonyorchestraonconcerthallstages,howthesephysicalconditions
affecttheplayersandultimatelyhowtodesignvenuessuitableforsymphonyorchestras. This
wasinvestigated byuseofseveraldifferent approaches,including questionnaire surveysand
dialoguewithmusicians,scaleandcomputermodellingandmeasurementsofexistingstages.
The results from the orchestra collaborations indicate that the following are of most concern
for players regarding acoustic conditions: hearing all other players in the orchestra clearly
and having sound from others well balanced with the sound of their own instrument and the
acoustic response from the main auditorium. These subjective aspects appear to relate to
complex perceptual effects like the precedence effect, masking effectsand the cocktail-party
effect. When relating these effectstophysicalconditions, a narrowandhigh stage enclosure
withthestagehighlyexposedtothemainauditoriumappearsmostbeneficial.
Regarding musicians’ impressions of actual stages and objective measurement results,
existing methods for assessing the stage acoustically by use of omnidirectional transducers
without the orchestra present were found to have only limited relevance. The reliability and
validityofthemostcommonacousticmeasures(includingST)werestudiedindetail.
Fortheassessmentanddesignofstageenclosures,newmethodsandobjectivearchitectural
measures have been proposed. A combination of acoustic and architectural measures are
found to successfully discriminate the most preferred from the least preferred stages of
purpose-builtconcerthalls. Theresultsfromjudgementsofexistingstagessupportthefinding
ofanarrowandhighstageenclosurewithahighlyexposedstagebeingmostbeneficial. The
objectivemeasuresstudiedaresimplifiedrepresentationsofrealacousticconditions. Howto
improvetheassessmentofacousticconditionsonstageisalsodiscussed.
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Preface
Thisthesisissplitintoninemainchapters:
Chapter1: Introduction.
Chapter2: Backgroundofthestudy. Theliteraturereview.
Chapter3: Musicians’impressionsofacousticconditions. Studiesofimpressionsofacous-
ticconditionsonstageingeneralterms.
Chapter4: Soundpropagationwithinasymphonyorchestra. Studies of how the sym-
phonyorchestraitselfaffectsoundpropagationbetweenplayers.
Chapter5: Theeffectofreflectedsoundbacktowardsasymphonyorchestra. Studiesof
howreflectedsoundmayaffectperceivedconditionsamongtheplayers.
Chapter6: Computermodellingofstageenclosuresincludingafullsymphonyorchestra.
Studies ofhowtorepresentasymphonyorchestraincomputermodels. Thedeveloped
representation of an orchestra is used to study resulting acoustic responses under
differentstageenclosuredesigns,withasymphonyorchestrapresentonstage.
Chapter7: Acousticmeasuresforassessingacousticconditionsonstage. Studiesofthe
validity and reliability of acoustic responses and measures, assessed without a sym-
phonyorchestrapresentonstage. Values oftheacousticmeasuresarecomparedwith
subjectiveimpressionsforasetofexistingstages.
Chapter8: Impressionsofeightperformancespacesvisitedregularly. Studiesofoneor-
chestra’s impressions of acoustic conditions in eight performance spaces they visit
regularly.
Chapter9: Overalldiscussionandconclusions.
Preliminary results from the research project forming this thesis were presented at interna-
tional conferences on acoustics (Barron & Dammerud (2006), Dammerud & Barron (2007)
andDammerud&Barron(2008)). Copiesofthesepapersarenotincludedinthisthesis.
ThisthesiswaspreparedinLATEX(setfordouble-sidedprinting)usingMiKTeXandLEd.
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Contents
1 Introduction 15
2 Backgroundofthestudy 19
2.1 Physicalobjectivesoundbehaviourwithinsymphonyorchestras . . . . . . . . 19
2.2 Theimpressionsofacousticconditionsonstage . . . . . . . . . . . . . . . . . 22
2.2.1 Studiesofgeneralimpressions . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.2 Studiesofimpressionsofspecificstages . . . . . . . . . . . . . . . . . 24
2.2.3 Laboratoryexperiments . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.3 Proposedacousticmeasures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.4 Effectofstageenclosureforconductorandaudience . . . . . . . . . . . . . . . 31
2.5 Approachesusedforthisstudy . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3 Musicians’impressionsofacousticconditions 35
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2 Questionnairemethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3 Questionnaireresultsingeneral . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.4 Openquestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.4.1 Non-acousticissuesimportantonstage . . . . . . . . . . . . . . . . . . 37
3.4.2 Favouritehalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.4.3 Preferenceforrisers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.4.4 Hearingothersandoneself . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.4.5 Statementsongoodacousticsforperformers . . . . . . . . . . . . . . . 39
3.4.6 Informationcontainedin,anddirectionofreverberantsound. . . . . . . 40
3.4.7 Bloomandprojection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
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