8/14/2019 Poster Tom Barcelone 03-10-07-2

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Study of a 3D audio-motor coupling with an electromagnetic motion capture deviceThomas Hoellinger1, Johanna Robertson1,2, Malika Auvray1, Agns Roby-Brami1,2, & Sylvain Hanneton1

1 Laboratoire de Neurophysique et Physiologie, CNRS UMR 8119, Universit Paris 5

2 Dpartement de Mdecine Physique et Rducation, Hpital Raymond Poincar, Garches, France

INTRODUCTION

Sensorysubstitutiondevicesconvertinformationnormallyprocessed

byonesensorymodality(e.g.,vision)intostimulationprovidedthroughano-

thersensorymodality(e.g.,audition)[1].Manystudieshaveshownthefeasibi-

lityofconvertingvisualinformationintosounds[2].However,thesensorimo-torparametersinvolvedinthelearningofsensorysubstitutiondevicesremain

unknown.

Theaimofthestudyreportedhereistwofold:

1)Toinvestigateparticipantsabilitytolocalizeasourcewithina3Dvisual-to-

auditoryenvironmentandtoinvestigatewhetherperformancedependsonthe

emplacementofthesensor(handversushead)

2)Toinvestigatethekinematicsoftheparticipantsheadandhandwhileadap-

tingtothisnewsystem.

MATERIAL & METHODS

Participants 10blindfoldedsightedparticipants(agerange:25-50years)tookpartinthisexperiment.Noneof

theparticipantssufferedfromhearingdeficits(asassessedbyauditorytests)ororthopaedicorneuro-

logicaldeficits.

Experimental Set-Up WeusedanElectromagneticdevice(Polhemus)connectedwitha3Daudiorenderingsystem(Ope-

nAl)thatprovidesauditoryfeedbackofmovements.

Themodelworkswithalistener(sensor)andanaudiosource.Thesoundreceivedbythelistenerde-

pendsonitspositionandorientationwithrespecttothesource.Inthiswaythesoundrecordedvaries

inintensity(Eq.1.)andinfrequency(computedbytheaudiodevice).Thesourcewasabuzzing

soundwithsignificantharmonicsbetween100and2000Hz.

Task Theaimoftheparticipantswastocatchafixedaudiosourcewiththeirhand.Thesoundwasper-

ceivedbytheparticipantsusingvirtualears(thelistener)locatedeitherontheirhand(handmode)

orontheirhead(headmode).Thesoundreceivedbytheparticipantswasmodulatedaccordingto

thepositionandorientationofthevirtualears.(Fig.1).Foreachmode,theexperimentconsistedof

3blocksof9trials,givingrisetoatotalof54trialsperparticipant.

Sound spatialisation modeling Accordingtothemodelused,theintensitydecreasesandthesoundisslightlymuffledastheliste-

nersensormovesawayfromthesource.

ThesoundattenuatesaccordingtotheEquation1(Eq.1)below:

RESULTS

Performances

Fig.2:Theparticipantslevelofperformancewassignificantlyhigherinthehandmode(thele

naturalmode)thanintheheadmode.

Inaddition,weobservedforbothmodesablockeffectwithasignificantincreaseinthesuccess

rate(F[2,18]=5.87,p