Table Of ContentProduction and Application of Room Impulse Responses for
Multichannel Setups using FLOSS Tools
Florian HOLLERWEGER Martin RUMORI
A–4020 Linz University of Music and Performing Arts Graz
Austria Institute of Electronic Music and Acoustics
fl[email protected] Inffeldgasse 10 · A–8010 Graz · Austria
[email protected]
Abstract time limited. Moreover, they provide an ef-
ficient method for documenting multichannel
Wepresenttheoutcomesofaseriesofroomimpulse
response(IR)measurements. Wehaverecordedbin- pieces in a format that can be played back on
aural,Ambisonics-encodedandregularstereo/mono a simple pair of headphones, but nevertheless
IRs of multichannel loudspeaker arrays in various conveys the acoustic spatiality intended by the
concerthallsinAustria,NorthernIreland,Germany composer. Realtime convolution engines such
and New Zealand. The resulting IRs and accompa- as BruteFIR or Jconvolver extend the useful-
nyingdocumentationhavebeenmadepubliclyavail-
ness of BRIRs towards real-time audio input.
ableonawebsiteforcomposerstouseintheproduc-
Since the publication of our last paper, we
tionanddocumentationoftheirmultichannelpieces.
have conducted additional room impulse re-
Thepaperalsodiscussesseveralcustom-writtenshell
sponse recordings, using both binaural and
scripts and extensions to the Aliki and Jconvolver
software packages, which we have developed for the other recording techniques, in a variety of con-
production of the presented IRs. cert halls. One purpose of this paper is to pro-
vide an overview of these recordings (cf., sec-
Keywords tion 2) and the resulting IR repositories, which
Impulse response, binaural auralisation, virtual we have made freely available (cf., section 5).
acoustics, convolution reverb We also present some examples of how differ-
ent artists have applied these impulse responses
1 Introduction
(cf., section 4).
In an earlier paper [Rumori et al., 2010], we Free/Libre Open Source Software (FLOSS)
have discussed binaural room impulse responses packages have played a central role in the pro-
(BRIRs), i.e., impulse responses (IRs) recorded duction of the IRs that we present, and are also
usingadummyheadina‘real’room,asopposed essential for their actual application. The cre-
to an anechoic chamber. We have described the ative use of IRs is an area of audio processing
usefulness of BRIRs for the pre-production and where the limited scope of commercial software
documentation of multichannel electroacoustic packages can easily become apparent. The abil-
compositions. By recording the BRIRs of all ity to customise many of the FLOSS tools that
loudspeakers in a multichannel electroacoustic we have used was both welcome and necessary
concert hall, one can generate binaural mix- to achieve our goals. Another purpose of our
downs of pieces composed for and/or performed paper is to provide an overview of our personal
on that loudspeaker array. When listened to on extensions to FLOSS tools such as Aliki and
stereo headphones, such a mixdown preserves Jconvolver (cf., section 3).
notonlythehall’sreverberationcharacteristics,
2 Recording Sessions and Venues
but also the perceived 3D direction of all loud-
speakers and phantom sources between them. 2.1 IEM CUBE and SARC Sonic Lab
BRIRs thus combine the advantages of single- TheCUBE concerthallattheInstituteofElec-
source stereo IRs used in standard convolution tronicMusicandAcoustics(IEM)inGraz,Aus-
reverbs with those of head-related IRs usually tria is a small concert space equipped with 24
recorded in anechoic chambers. Tannoy System 1200 loudspeakers, which are
Binaural mixdowns created from BRIRs as- arrangedinahemisphereabovethelistenerand
sist the composer with the pre-production of optimised for Ambisonics playback.
multichannel pieces written for concert halls The Sonic Lab at the Sonic Arts Research
where access is often restricted and rehearsal Centre, Queen’s University Belfast, is a large
Figure 3: The Adam Concert Room (ACR)
at Te K¯ok¯ı New Zealand School of Music in
Figure 1: The CUBE at the Institute of Elec-
Wellington (photograph by courtesy of Stephen
tronicMusicandAcousticsinGraz(photograph
Gibbs)
bycourtesyoftheGrazUniversityofMusicand
Performing Arts)
In October 2011, an IR recording session
was conducted in the ACR to conclude a one-
trimester seminar on Spatial Audio. The final
repository includes binaural IRs (recorded by
a Kemar 45BA) and experimental Ambisonics-
encoded IRs (CoreSound TetraMic) of a cir-
cular eight-channel speaker array (Genelec
1037B/C), plus standard stereo IRs (X/Y pair
ofNeumann KM184s)ofthesamearrayandfor
a single centred speaker. The repository is ac-
companied by extensive documentation of the
production process and includes several demo
scripts to illustrate the usage of the final IRs.
2.3 Academy of Media Arts Cologne
Figure 2: The Sonic Lab at the Sonic Arts Re-
search Centre in Belfast (photograph by cour- The auditorium of the Academy of Media
tesy of Gawain Morrison) Arts Cologne (KHM) is a medium-size, multi-
purpose hall used for lectures, presentations,
filmscreeningsandconcerts,thelattermostlyof
electroacoustic concert hall whose acoustics can
an experimental kind, featuring electroacoustic
beadaptedthroughmovablewallpanels. Atthe
and improvised music. The reverb time of the
timeofourrecording, theSonicLabfeatured40
hall is rather short as it is mainly conceived for
full-range speakers (Meyer Sound and Genelec)
good speech intelligibility.
and 6 subwoofers.
In November 2011, a hands-on workshop
Details on the IRs that we have recorded in
called Raumfaltung on measuring and using im-
the CUBE and the Sonic Lab can be found in
pulse responses has been carried out at KHM.
our previous paper [Rumori et al., 2010], so we
During the workshop, a “classic” speaker ring
will not reiterate them here.
of eight K+H O108 has been set up in the au-
ditorium and room impulse responses for each
2.2 New Zealand School of Music
of the speakers were measured using an array
The Adam Concert Room (ACR) is located at
of different microphones: two kinds of custom-
the Kelburn Campus of Te K¯ok¯ı New Zealand
built dummy heads,1 an ORTF configuration of
School of Music (NZSM), a joint venture of
two Schoeps MK4, a small AB configuration of
Massey University and Victoria University of
two Schoeps MK2s, a Soundfield ST250 first-
Wellington. The ACR is a medium-size concert
hall which is predominantly constructed from 1BinauralmicrophonesSellmeierGrey andSellmeier
wood and seats up to 200 people. Brown, both constructed by Wilfried Sellmeier
Figure 4: The microphone setup at Academy of Figure 5: Speaker rig and measurement setup
MediaArtsCologne(photographbycourtesyof at Ligeti Hall in MUMUTH Graz
Dirk Specht)
ent perspective on the instrument. As part
order Ambisonics microphone and a Behringer of the VirtualMUMUTH subproject (see sec-
ECM8000 measurement microphone as a refer- tion4.4),manyroomimpulseresponsemeasure-
ence channel above one of the dummy heads. ment sessions were undertaken between Febru-
The impulse responses are suitable for mono ary 2011 and August 2012, for several combina-
orstereoconvolutionreverbapplicationsaswell tions of loudspeaker configurations and micro-
as for auralisation of up to eight channels or phone (i.e. listening) positions.
binaurally rendered horizontal Ambisonics.
In order to achieve a high versatility, the
measurements were done using an arrange-
2.4 MUMUTH Graz
ment of multiple microphones: a Bru¨el&Kjær
MUMUTHGrazistheHouseofMusicandMu-
dummy head with additional DPA4060 cap-
sic Theatre at the University of Music and Per-
sules mounted on its temples, a Schoeps spher-
forming Arts Graz (KUG). Its main hall, the
ical stereo microphone, an Ambisonics Sound-
Ligeti Hall, is a multi-purpose space for theatre
field mic, a large AB configuration of two
andoperaproduction, concerts, danceandelec-
Schoeps MK2s and a mono reference. Due to
troacoustic music. It features a rig of 33 speak-
the high number of channels and the resulting
ers with a motorised position control, which al-
large amount of data, some of the measurement
lowsforadjustingtheheights,panandtiltofev-
tools needed to be extended as described in sec-
eryspeakerindividually. Thisway,speakercon-
tion 3.
figurationscanbechangedandevaluatedrather
quickly. Additionally, Ligeti Hall is equipped
3 Tools and Customisations
with 64 fixed smaller speakers and eight sub-
woofers, which belong to a virtual room acous-
The abovementioned measurements and their
tics system, but which can be also directly fed
post-production have been carried out entirely
with arbitrary signals. Further speakers and
using FLOSS tools. The central tool being used
subwoofers may be hung or installed on stands
forallthevenuesdescribedhereisAliki byFons
if needed.
Adriaensen [Adriaensen, 2006a]. In larger mul-
Since fall 2010, the artistic research project
tichannel settings with many speakers, several
The Choreography of Sound2 is carried out at
microphone channels and lots of measurement
the Institute of Electronic Music and Acous-
iterations like at MUMUTH (cf. section 2.4), a
tics (IEM) at KUG. For the case studies of this
few additions and adaptations to Aliki became
project, the Ligeti Hall is considered the main
necessary.
instrument. Asaccesstimestothehallarequite
For post-processing and using the measured
limited, a binaural auralisation of its acoustic
impulseresponses, somefurthertoolshavebeen
properties became desirable, which turned out
developed,suchasscriptsbasedonsoxfortrim-
to be also quite useful for taking up a differ-
mingandfadingandascriptforgeneratingcon-
2http://cos.kug.ac.at,lastretrieved2013–02–17, figurations for Jconvolver, a high-performance
see also [Eckel et al., 2012] convolution engine [Adriaensen, 2006b].
3.1 Aliki and around
Aliki is a powerful and free impulse response
measurementframework, whichimplementsthe
swept-sine measurement method [Farina, 2000].
It provides means for generating the sweep sig-
nal, playing it back and recording the room’s
response, for deconvolving the recorded sweep
inorderto gettheimpulseresponse, somefunc-
tionality for editing the resulting responses and
for exporting them.
3.1.1 Automated speaker channel
switching
In a larger setup such as in MUMUTH (cf. sec-
tion 2.4), it is desirable to carry out multiple
iterations, e.g. for several speaker channels in
a row, in an automated way. Unfortunately,
standard Aliki only offers eight output channels
and no means of directly switching them au-
tomatically. There is a functionality though for
specifyingthenumberofiterationsandatrigger
command, which is executed once every cycle.
Figure 6: Capture dialog of the extended Aliki
For the automated measurements described
using 16 input channels, trigger and reset com-
here, this trigger has been used to send an OSC
mands and an initial delay
message to a small SuperCollider patch, which
receivesthesweepsignalonasingleinputchan-
The custom version of Aliki was modified
nel (fixed output on channel 1 of Aliki) via the
such that the number of audio input channels
Jack audio server. Upon an incoming OSC trig-
could be specified as a command line option at
ger message, the sweep signal is routed sequen-
startup. In the same manner, also the num-
tially to the corresponding loudspeaker output
ber of output channels has been parametrised,
channels. This way, also more complex channel
although this was not needed for the scope of
sequences or groups with non-contiguous chan-
these measurements.
nel numbers could be easily realised.
For convenience, the custom version of Aliki 3.1.3 Initial delay
(as used in MUMUTH) also contained a reset Whilecarryingoutalarge, automatedsequence
command field, which could be triggered by a ofiterations, itmightbeconvenienttoleavethe
button. It was used to send another OSC mes- space being measured in order to minimise the
sage to reset the channel routing to the starting extra noise induced (and to minimise the sweep
point. levelinthepooroperator’sears). Inthecustom
version of Aliki, an initial delay time may be
3.1.2 More input and output channels
specified which allows for leaving the space well
Standard Aliki provides eight recording chan-
before the first sweep starts.
nels for the microphone signals. In MUMUTH,
Before Aliki was customised for that, some-
due to the high number of speaker channels (up
times the first measurement (first sweep play-
to 128) and long sweep times (> 10 sec), the
back) was regarded a “Nop” and discarded
actual net measurement time was already so
later. This creates problems such as reduced
long that it seemed appropriate to add a few
flexibility (fixed sweep length depending on the
more microphones, as those additional impulse
measurement) and messed-up channel numbers
responsescome“forfree”(timewise)andmight
when exporting the impulse responses to single
be suitable for future applications, even if the
files automatically.
focus was on binaural room impulse responses.
Thus,aconfigurationof13microphonechannels 3.1.4 CLI deconvolution and export
arose, including a dummy head, several differ- Aliki includes the deconvolution stage of the
ent stereo pairs, a Soundfield mic (Ambisonics recorded sweeps in order to generate the actual
A-format) and a reference channel. impulse responses, and an export function for
convertingfromAliki’ssoundfile format (.ald) cilitates the handling of large sets of files with
to standard formats such as .wav or .aiff. a contiguous number part of a fixed width (e.g.
Aliki’s file format supports multiple sections in zero-padded)intheirfilenames. Acertainrange
a single file, which correspond to the iterations of numbered files may be processed or all con-
of a sequential measurement. Both the decon- tiguously numbered files found, starting from a
volution and the export may be performed for givenindex. Fortheoutputfiles,adifferentfile-
a single section of a file or for all sections of name pattern and a different starting index for
that file, using the same parameters. The lat- filename numbering may be specified, which en-
teroptioncomesinhandywhenpost-processing ables simple renaming operations for chunks of
measurementswithahighnumberofiterations. files at the same time as processing.
However, the measurements reported here, imptrim.sh allows for separately specifying
especially those in MUMUTH (cf. section 2.4), two portions of the audiofiles to be cut from
not only included many iterations per file but the beginning, e.g. a compensation portion in
alsoalargenumberofthosefiles,duetothehigh samples and another trim in seconds. Further
amount of combinations of loudspeaker config- options include the overall length of the result-
urations and microphone positions. Therefore, ing impulse response, the length and shape of
the tedious and error-prone task of manually the fade-in and fade-out and a gain factor. Op-
loading each file for deconvolution and export tionally, a stamp file may be generated in the
was replaced by two custom command-line ap- output directory as a log for the parameters be-
plications, aliki-convol and aliki-export, ing used for processing.
which are basically factored-out versions of the
3.2.2 remapch.sh
respective built-in functions.
This is a helper script used for the MUMUTH
Corresponding to the GUI options in Aliki,
measurements which actually does not process
aliki-convol allows for specifying the start
any audio but only facilitates renaming chunks
andendtimesofthedeconvolutionandwhether
of numbered impulse response files. It is in-
one or all sections of the file shall be processed.
cluded here because it might be of general in-
Likewise, aliki-export accepts options for the
terest for adapting it to other settings.
export file format and bit depth, whether a sin-
Measuringandexportingasequenceofspeak-
gle section, all sections in one file or all sections
erswhosechannelnumbersdonotstartat1will
in separate files shall be exported, the file name
result in filenames which do not match the orig-
base and an offset for file numbering.
inal channel numbers anymore. For example,
3.2 Post-processing impulse responses measuring the MUMUTH sky (channels 65–
128) will result in numbered filenames ranging
All impulse responses taken in the above-
from 1 to 64. This may be avoided by using
mentioned measurement series were not post-
aliki-export and specifying an offset for the
processed in Aliki, but through separate tools
output filename (see section 3.1.4).
or scripts. This is mostly due to the high num-
But when carrying out a large sequence
ber of responses and the different applications
of measurements over a non-contiguous, i.e.
they are targeted at.
“sparse” array of channel numbers, the file-
Post-processing here basically means trim-
name number offset will be different for each
ming the impulse responses, compensating the
loudspeaker block. In MUMUTH for example,
measurement system latency at the beginning
whenmeasuringthehemisphere,cornerandsky
of the file, in some cases also the air travelling
speakersplustwosubwoofersinarow,thehemi-
time of the direct sound, adding a short fade-
sphere and corner speaker numbers will remain
in to the beginning, trimming the length of the
(channels1–33),thesubwooferchannels42and
impulseresponseandapplyingafade-outatthe
43 will be named 34 and 35, respectively, and
end. Othercommontasksaregainadjustments,
theskychannels65–128willresultinfilesnum-
either by a fixed factor or an individual normal-
bered from 36 to 99.
isation, and possibly resampling to a different
remapch.sh allows for entering such transla-
target sample rate.
tionsforcertainregionsofchannelnumbersinto
3.2.1 imptrim.sh asimpledatabasewithinthescript. Itmaythen
imptrim.sh is a shell script used for post- be used for renaming operations on chunks of
processing the MUMUTH measurements. It is response files in both directions, based on the
a simple wrapper script around sox, which fa- specified configuration (translation).
3.2.3 post export.sh for every recorded take, the IRs of all loud-
The post export.sh script was written specifi- speakers in the multichannel setup are nor-
cally for the production of the IRs of the Adam malised to the same target value. The nor-
Concert Room at the New Zealand School of malisation is deliberately performed prior
Music (cf., section 2.2). It provides an alter- to converting the IRs to different sample
native implementation of some of the functions rates, despite the theoretical possibility of
provided by the imptrim.sh and remap.sh clipping due to intersample peaks (which
scripts, as well as some additional features. can in practice be avoided by choosing the
target value low enough). If an IR was to
post export.sh aims at automating the
be normalised after resampling, intersam-
entire IR post-processing after the recorded
ple peaks might translate to slightly vary-
sweeps have been deconvolved and exported to
ing peak levels for different sample rates.
.wav. Similar to the tools presented so far, the
The same IR would then be normalised by
idea is to automate the process as much as pos-
a different amount for each sample rate.
sible. Thus, all edits are performed with com-
mand line tools such as sox rather than graph- Resampling from 96 to 44.1 and 48 kHz, us-
ically through the Aliki GUI. Being very much ing the sndfile-resample tool from the
tailored to the specific requirements of the pro- samplerate-programs Debian package.
ductionitwasusedfor, thescriptisnotentirely
generic, but hopefully still useful for other IR 3.3 Jconvolver helpers
measurementsafteraccordingadaptations. The The tools described in this section do not
script performs the following processing steps: actually belong to the measurement or post-
processing of impulse responses but to their
Renaming oftheIRsexportedfromAlikiwith application. In many use cases of the mea-
mv, such that they are named according to surements described here, the free command-
the respective loudspeaker’s direction. For line convolution engine Jconvolver [Adriaensen,
example, the suffix nnw denotes a loud- 2006b] has been used. Its highly efficient imple-
speaker in north-north-west direction, de- mentation of the so-called Gardner convolution
liberately (but falsely) assuming that the using increasing partition sizes makes it espe-
listener always faces north. cially suitable for long impulse responses and
many channels, while at the same time allowing
A-to-B format conversion of the experimen-
for low-latency operation.
tal Ambisonics-encoded IRs. This step is
performed using the tetrafile tool by 3.3.1 genjconv.sh and genjconvn.sh
Fons Adriaensen, who also kindly provided Jconvolver uses a configuration file in OSC-
the required calibration file for the specific message-style syntax for describing the convo-
TetraMic (serial (cid:155) 2099) that was used in lution matrix. The settings include the number
the recording. ofinputandoutputchannels,theminimumand
maximum partition size, the locations, names
Latency compensation countering the ef-
and channels of the soundfiles containing the
fectsoftherecordingsystem’slatency,sim-
impulse response and a couple of options for
ilar to the imptrim.sh script.
each impulse response, such as gain or delay.
For the variety of impulse response sets de-
Trimming theIRstoapre-definedlengthwith
scribed in this paper, especially those of dif-
sox, similar to imptrim.sh.
ferent combinable loudspeaker groups in MU-
Fade-in and fade-out with sox, similar to MUTH (cf. section 2.4), one should be able to
imptrim.sh. quickly and flexibly generate Jconvolver config-
urations. For this task, the genjconv.sh and
Normalisation oftheIRstoanarbitrarypeak
genjconvn.sh scripts have been conceived.
value in dB.3 With the help of some bash
Both scripts write a Jconvolver configuration
logic,thisisperformedingroups,suchthat
file to stdout based on a list of impulse response
files read from stdin. The general usage scheme
3This step is not strictly necessary, assuming that a
therefore is:
floating point number representation is used for the un-
derlying audio files, and considering that in a binaural
mixdownofamultichannelpiece,manysignalswilleven- ls ir_*.wav | sort -n | genjconv.sh \
tually be superimposed anyway. > irjconv.conf
The scripts try to be smart with respect to figuration, or the initial elements of the new
the input and output channels: By default, the path from which the complete path is guessed.
numberofinputchannelsoftheconvolutionma- This is done by concatenating the given initial
trix is assumed to equal the number of input path and the existing one, subsequently strip-
files, while the number of output channels is de- ping one hierarchy from the front of the exist-
termined from the number of channels of the ing path, until a directory with the resulting
first input file. Both parameters may also be name is found in the filesystem. Although this
specified manually, as well as the number of in- is a very simple mechanism, it turned out to be
put file channels used and a channel offset. quite effective in many practical use cases.
genjconv.sh maps the input channels of the
convolution matrix sequentially to the list of 4 Application examples
input impulse response files. It is possible to
4.1 Electroacoustic compositions
specify exclude regions for both input and out-
put channel numbers of the matrix in order to In our previous paper [Rumori et al., 2010],
leave “holes”, i.e. produce a “sparse” convolu- we have already discussed some artistic appli-
tion matrix. cations of our impulse responses by different
genjconvn.sh parses for numbers in the in- composers. Justin Yang, Gary Kendall, and
put impulse response filenames and creates John Moeller have used the IRs recorded in the
a matrix whose input channel numbers are SARC Sonic Lab for the production and docu-
mapped to the corresponding filenames. Cur- mentation of several multichannel electroacous-
rently, this works for zero-padded three-digit tic compositions. Dirk Specht and Gerriet K.
numbers directly in front of the last dot in Sharma have published binaural mixdowns of
the filename. This facilitates the generation of their multichannel pieces on two CDs, using the
“sparse” convolution matrices and ensures that IRs recorded in the IEM CUBE.
impulseresponsefilesforcertainspeakergroups
4.2 Pop Production
arealwaysassociatedwiththerightinputchan-
nels, independent of the total number of input Nic McBride has used the binaural room im-
files given (assuming that they are named ac- pulse responses from the Adam Concert Room
cordingly). at the New Zealand School of Music to create
For completeness, both scripts allow for spec- a headphone mix of eight distinct stems in a
ifying a fixed gain factor for all impulse re- pop production entitled L’addio Scontato. This
sponses, the base path to be used, the mini- example represents an original use of BRIRs in
mum partition size, and the maximum impulse the sense that the final production was never
response length. primarily targeted at multichannel playback –
one cannot really speak of a stereo ‘reduction’
3.3.2 jjconvolver.sh
in this context. According to Nic, the BRIRs
When using manually written or automatically
allowed her to achieve a natural-sounding spa-
generated Jconvolver configuration files across
tial separation in the final binaural mix, which
differentsystems,acommonproblemisthatthe
has been released online [McBride, 2012].
impulse responses reside in a different location
than specified in the configuration file as an ab- 4.3 Audio Augmented Environments
solute path. Often, the difference is negligible
Binaural impulse responses recorded in sev-
and is caused only by the different name of the
eralofthedescribedmeasurementsessionshave
home directory or a few initial path elements,
been used by Martin Rumori in sound instal-
as the deeper structure of a commonly used im-
lations which form different kinds of audio-
pulseresponsedatabaseislikelytobethesame.
augmented environments. They include naviga-
jjconvolver.sh tries to solve this prob-
ble virtual environments incorporating a head-
lem by simply replacing the /cd directive in phone tracking system, such as Parisflˆaneur,4
the Jconvolver configuration, generating a tem-
or mixed-reality installations, where the virtual
porary file and starting Jconvolver using the
layer blends with the real auditive surround-
adapted configuration. It acts as a frontend
ing of the listener, using open-loop headphones,
script to Jconvolver and passes through any of such as in ruhrprotokolle.5
its options. Additionally, it accepts a few ex-
tra options which either specify a full path to 4http://www.rumori.at/do/parisflaneur
completely replace the existing one in the con- 5http://www.ruhrprotokolle.de
4.4 VirtualMUMUTH the Austrian Science Fund (FWF) under the
Within the research project The Choreography project code PEEK AR41.
of Sound (see section 2.4), the impulse re- Fons Adriaensen has provided much-
sponses measured in MUMUTH’s Ligeti Hall appreciated support for his excellent Aliki,
areusedforanauralisationoftheacousticprop- Jconvolver and Tetrafile packages.
erties of the space. The Jconvolver helpers de- Wewould also liketo acknowledge the contri-
scribed in section 3.3 have been integrated with butions of Bridget Johnson, Jason Post, Stuart
the CoS software framework conceived in Su- Macann, Roy Carr, Dugal McKinnon and Mark
perCollider, which will be published along with McGann at the New Zealand School of Music,
the project’s documentation in the second half and of Mark Poletti at Industrial Research Ltd.
of 2013. The auralisation is completed by a vi- in Lower Hutt.
sualthree-dimensionalnavigablemodelofLigeti At the Sonic Arts Research Centre in Belfast,
Hall, realised in Blender and also integrated we would like to thank Andr´es Cabrera, Gary
with the software library. Kendall, John Moeller, Justin Yang and Chris
Participants of the CoS workshop at Impuls Corrigan.
Academy 20136 inFebruary2013andartistsin- Thanks to Anthony Moore and Dirk Specht
vited to the Mind the Gap! symposium in MU- fororganisingthemeasurementworkshopatthe
MUTH in March 20137 prepared their contri- Academy of Media Arts Cologne.
butionsusingtheVirtualMUMUTH standalone
References
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Fons Adriaensen. 2006a. Acoustical impulse
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patches, scripts and helpers introduced in sec-
FonsAdriaensen. 2006b. Designofaconvolu-
tion 3 as well as the VirtualMUMUTH aurali-
tion engine optimised for reverb. In Proceed-
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ings of the International Linux Audio Con-
made freely available at http://irdb.kug.ac.
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at.
Gerhard Eckel, Martin Rumori, David Pirr`o,
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FLOSS tools continue to play an essential role ment of impulse response and distortion with
in the recording and usage of such IRs, due to a swept-sine technique. In Audio Engineering
the customisability that these tools offer, and Society Preprint 5093.
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Nic McBride. 2012. L’addio scontato.
packages.
http://soundcloud.com/amynicmcbride/
We are looking forward to feedback from mu-
l-addio-scontato-elyssa-vulpes. Pro-
sic producers and composers who would like to
duced by Nic McBride, written and per-
use the presented impulse responses for their
formed by Elyssa Vulpes. Last retrieved on
own work, hopefully in unusual and original
12 February 2013.
ways that we have not envisioned here.
Martin Rumori, Florian Hollerweger, and
7 Acknowledgements
Andr´es Cabrera. 2010. Binaural room im-
The measurements at MUMUTH Graz were pulse responses for composition, documenta-
carried out within the Choreography of Sound tion, virtual acoustics and audio augmented
artistic research project initiated by Gerhard environments. In Proceedings of the 26th
Eckel and Ram´on Gonz´alez-Arroyo, funded by VDT International Convention, pages 670–
679, Leipzig.
6http://www.impuls.cc
7http://www.researchcatalogue.net/view/33841/
37723/1022/567
