SUNDAY MORNING, 25 JUNE 2017 BALLROOM B, 8:00 AM TO 10:15 AM Session 1aID ...

84 Pages·2017·0.59 MB·English

SUNDAYMORNING,25JUNE2017 BALLROOMB,8:00A.M.TO10:15A.M.
Session1aID M
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Interdisciplinary:OpeningCeremonies,KeynoteLectures S
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8:00
ThePresidentsoftheEuropeanAcousticsAssociationandtheAcousticalSocietyofAmericawillwelcomeattendeestoAcous-
tics’17Boston.
InvitedPapers
KeynoteIntroduction—8:15
8:20
1aID1. Computational analysis of acoustic events in everyday environments. Tuomas Virtanen (Tampere Univ. of Technol.,
Korkeakoulunkatu1,TampereFI-33720,Finland,tuomas.virtanen@tut.fi)
Soundscarryalargeamountofinformationaboutoureverydayenvironmentandphysicaleventsthattakeplaceinit.Recentadvan-
cesinmachinelearningallowsautomaticmethodstoanalyzethisinformation,forexample,bydetectingandclassifyingacousticevents
producedbyvarioussources.Thisallowsseveralapplications,forexample,inacousticsurveillance,context-awaredevices,andmulti-
mediaindexing.Thistalkwillpresentsignalprocessingandmachinelearningmethodsthatcanbeusedtodetectandclassifyeveryday
acoustic events originating, e.g., from vehicles, human activity, human and animal vocalizations, in everyday environments. It will
describethescientificchallengesinsuchmethods,forexample,manysourceshavinghighlysimilarspectralcharacteristicsandmultiple
sourcesbeingactivesimultaneously.Itwillexplainhowstate-of-the-artmethodsbasedonadvanceddeepneuralnetworktopologies
dealwiththesechallenges.Thetalkwillalsodiscussthepracticalchallengesrelatedtothedevelopmentofthemethods,suchasacquisi-
tionofdatathatisusedtodevelopthemethods.Itwillpresentresultsfromrecentevaluationsofeventdetectionsystemsandillustrate
themusingaudioandvideoexamples.
KeynoteIntroduction—9:15
9:20
1aID2.Asoundfutureforacousticmetamaterials.StevenCummer(DukeUniv.,POBox90291,Durham,NC27708,cummer@
duke.edu)
Thefieldof acousticmetamaterialsborrowedideasfromelectromagneticsandopticstocreate engineeredstructuresthat exhibit
desiredfluidorfluid-likepropertiesforthepropagationofsound.Thesemetamaterialsofferthepossibilityofmanipulatingandcontrol-
lingsoundwavesinwaysthatarechallengingorimpossiblewithconventionalmaterials.Metamaterialswithzero,ornegative,refrac-
tiveindexforsoundoffernewpossibilitiesforacousticimagingandforthecontrolofsoundatsubwavelengthscales.Thecombination
oftransformationacousticstheoryandhighlyanisotropicacousticmetamaterialsenablesprecisecontroloverthedeformationofsound
fields,whichcanbeused,forexample,tohideorcloakobjectsfromincidentacousticenergy.Andactiveacousticmetamaterialsuse
externalcontrolandpowertocreateeffectivematerialpropertiesthatarefundamentallynotpossiblewithpassivestructures.Challenges
remain,includingthedevelopmentofefficienttechniquesforfabricatinglarge-scalemetamaterialstructuresand,critically,converting
excitinglaboratoryexperimentsintopracticallyusefuldevices.Inthispresentation,Iwilloutlinetherecenthistoryofthefield,describe
someofthedesignsandpropertiesofmaterialswithunusualacousticparameters,discussexamplesofextrememanipulationofsound,
andfinally,provideapersonalperspectiveonfuturedirectionsinthefield.
10:15–10:40Break
3451 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3451
SUNDAYMORNING,25JUNE2017 ROOM207,10:35A.M.TO12:20P.M.
Session1aAAa
ArchitecturalAcoustics:EcholocationbyPeopleWhoareBlind
MonikaRychtarikova,Cochair
FacultyofArchitecture,KULeuven,Hoogstraat51,Gent9000,Belgium
DavidP.Garcia,Cochair
PhysicsandAstronomy,KULeuven,Heverlee,Belgium
Chair’sIntroduction—10:35
InvitedPapers
10:40
1aAAa1. Human echolocation in different situations and rooms. Bo N. Schenkman (Speech, Music and Hearing, Royal Inst. of
Technol.(KTH),Lindstedtsv€agen24,StockholmSE-10044,Sweden,[email protected])
People,especiallywhenblind,useecholocationtodetectobstacles,orientthemselves,andgetanawarenessoftheirenvironment.I
andcoworkershave,withmostlypsychophysicalmethods,studiedperceptualaspectsofhowpeopleaccomplishecholocation.Echolo-
cationwithlongcaneswhilewalkingwaspossiblebutdifficult.Theeffectsofthespectralcompositionoftheemittedsoundshadno
effects.Soundrecordingsinanechoicandconferenceroomsfromnon-walking,staticsituations,laterpresentedinalaboratoryshoweda
betterperformanceinanordinaryroomwithreflections,thaninananechoicroom.Wealsofoundthattherewasahigherperformance
withlongersoundingsoundsthanforshortclicks.Amongthedifficultiesfortheblindarehowtoavoidmaskingofsounds.Afewblind
areexceptionallyhighperforming.An“information-surplusprinciple”hasbeenproposed.Variousinformationsourcesareused,but
repetitionpitchseemsmoreimportantthanloudnessforecholocation.Amongothersources,timbremayalsoprovideinformation.There
mayexistatimegap,acousticgaze,forhowblindpeopleuseclicks.Itislikelyalsothatthereareatleasttwoprocessestakingplacein
thehearingsystemwhenlisteningforechoes,oneattunedtoshortsoundsandonetolongsounds.
11:00
1aAAa2. Auditory recognition of surface texture with various scattering coefficients. Monika Rychtarikova (Faculty of
Architecture, KU Leuven, Hoogstraat 51, Gent 9000, Belgium, [email protected]), Luka(cid:2)s Zelem (Facultyof Civil
Eng.,Dept.ofBldg.Construction,STUBratislava,Bratislava,Slovakia),LeopoldKritly,DavidP.Garcia(Phys.andAstronomy,Lab.
ofAcoust.,KULeuven,Heverlee,Belgium),VojtechChmel(cid:3)ık(FacultyofCivilEng.,Dept.ofBldg.Construction,STUBratislava,
Bratislava,Slovakia),andChristGlorieux(Phys.andAstronomy,Lab.ofAcoust.,KULeuven,Leuven,Belgium)
Humanecholocationisaknownabilityofpeopletograsptheinformationaboutthesurroundingenvironmentfrompurelyacoustic
information.However,theextenttowhatnormalsightedandblindpeoplecanauditorilyrecognizethesurfacetexture,suchasitsrough-
nessorotherdifferentsoundscatteringfeatures,isnotcompletelyknown.Inthispaper,weinvestigatetheabilityofpeopletodistin-
guish different types of surfaces by their sound reflections. Reflection patterns from 24 types of surface textures at two different
distanceswerecalculatedinfinitedifferencemethodandconvolvedwith“clicksound”inordertobeusedforperceptiontests.Twenty
normallysightedhumansubjectsparticipatedonthelisteningtestexperiment.
11:20
1aAAa3.Audiblesonarimagesgeneratedwithproprioceptionfortargetanalysis.RomanB.Kuc(Elec.Eng.,Yale,15ProspectSt.,
511Becton,NewHaven,CT06511,[email protected])
Someblindhumanshavedemonstratedtheabilitytodetectandclassifyobjectswithecholocationusingpalatalclicks.Anaudible-
sonarrobotmimicshumanclickemissions,binauralhearing,andheadmovementstoextractinterauraltimeandleveldifferencesfrom
targetechoes.Targetsofvariouscomplexityareexaminedbytransversedisplacementsofthesonarandbytargetposerotationsthat
modelmovementsperformedbytheblind.Controlledsonarmovementsexecutedbytherobotprovidedatathatmodelproprioception
informationavailabletoblindhumansforexaminingtargetsfromvariousaspects.Theaudiblesonarusesthissonarlocationandorienta-
tioninformationtoformtwo-dimensionaltargetimagesthataresimilartomedicaldiagnosticultrasoundtomograms.Simpletargets,
suchassingleroundandsquareposts,producedistinguishableandrecognizableimages.Morecomplextargetsconfiguredwithseveral
simpleobjectsgeneratediffractioneffectsandmultiplereflectionsthatproduceimageartifacts.Thepresentationillustratesthecapabil-
itiesandlimitationsoftargetclassificationfromaudiblesonarimages.
3452 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3452
11:40
1aAAa4.Investigateecholocationwithnon-disabledindividuals.AlessiaTonelli,LucaBrayda,andMonicaGori(IstitutoItalianodi
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Tecnologia,ViaMelen,Genoa16152,Italy,[email protected])
A
Visionisthemostimportantsenseonthedomainofspatialperception.Congenitalblindindividuals,thatcannotrelyonvision, N.
show impairments inperformingcomplex spatial auditorytasks.The echolocation technique allows blind peopleto compensate the U
audiospatialdeficit.Here,wepresentanoverviewofourworks.First,weshowthatalsosightedpeoplecanacquirespatialinformation S
throughecholocation,i.e.,localizeanapertureordiscriminatethedepthsofanobjectlocateinfrontofthem.Second,weidentified a
1
somekinematicvariablesthatcanpredicttheecholocationperformance.Third,weshowthatecholocation,notonlyhelpstounderstand
theexternalspace,butcaninfluenceinternalmodelsofthebody-spacerelation,suchastheperipersonalspace(PPS).Wediscussall
theseaspectsshowingthathumanbeingsaresensitivetoechoes.Spatialinformationcanbeacquiredbyecholocationwhenvisionisnot
availablealsoinpeoplethatnormallywouldacquirethesameinformationthroughit.Wefinallydiscussourresultsintermofrehabilita-
tiontechniqueforvisuallyimpairedpeople.
12:00
1aAAa5.Restoringanallocentricreferenceframeinblindindividualsthroughecholocation.TizianaVercillo(Psych.,Univ.of
Nevada,Reno,1664N.VirginiaSt.,Reno,NV89503,[email protected]),AlessiaTonelli(U-VIPUnitforVisuallyImpairedPeople,
Fondazione Istituto Italiano di Tecnologia, Genoa, Italy), Melvyn Goodale (The Brain and Mind Inst., London, ON, Canada), and
MonicaGori(U-VIPUnitforVisuallyImpairedPeople,FondazioneIstitutoItalianodiTecnologia,Genoa,Italy)
Recentpsychophysicalstudieshavedescribedtask-specificauditoryspatialdeficitsincongenitallyblindindividuals.Weinvesti-
gatedauditoryspatialperceptionincongenitallyblindchildrenandadultsduringdifferentauditoryspatialtasksthatrequiredthelocal-
ization of brief auditory stimuli with respect to either external acoustic landmarks (allocentric reference frame) or their own body
(egocentricreferenceframe).Earlyblindparticipantssuccessfullyrepresentedsoundlocationswithrespecttotheirbody.However,they
showedrelativepoorprecisionwhencomparedtosightedparticipantsduringthelocalizationofsoundwithrespecttoexternalauditory
landmarks,suggestingthatvisioniscrucialforanallocentricrepresentationoftheauditoryspace.Inaseparatestudy,wetestedthree
congenitallyblindindividualswhousedecholocationasanavigationalstrategy,toassessthebenefitofecholocationonauditoryspatial
perception.Blindecholocatorsdidnotshowthesameimpairmentinauditoryspatiallocalizationreportedforblindnon-echolocators,
butratherprovedenhancedprecisionandaccuracyascomparedtoblindnon-echolocatorsandsightedparticipants.Ourresultssuggest
thatecholocationcancompensateforthespatialdeficitreportedinearlyblindindividuals,likelybyreactivatinganallocentricreference
frameneededtoshapespatialrepresentationssimilartothosegeneratedbyvision.
3453 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3453
SUNDAYMORNING,25JUNE2017 ROOM208,10:35A.M.TO12:20P.M.
Session1aAAb
ArchitecturalAcoustics:SoundPropagationModelingandSpatialAudioforVirtualRealityI
DineshManocha,Cochair
ComputerScience,UniversityofNorthCarolinaatChapelHill,250BrooksBuilding,ColumbiaStreet,ChapelHill,
NC27599-3175
LauriSavioja,Cochair
DepartmentofMediaTechnology,AaltoUniversity,POBox15500,AaltoFI-00076,Finland
U.PeterSvensson,Cochair
DepartmentofElectronicSystems,NorwegianUniversityofScienceandTechnology,AcousticsResearchCentre,
TrondheimNO-7491,Norway
Chair’sIntroduction—10:35
InvitedPapers
10:40
1aAAb1.ExperiencewithavirtualrealityauralizationofNotre-DameCathedral.BrianF.Katz(Lutheries-Acoustique-Musique,
Inst.@’Alembert,UPMC/CNRS,@’Alembert,bo^ıte162,4,Pl.Jussieu,Paris75252Cedex05,France,[email protected]),BarteldN.
Postma(LIMSI,CNRS,Universit(cid:3)eParis-Saclay,Orsay,France),David Poirier-Quinot(Espacesacoustiquesetcognitifs,UMRSTMS
IRCAM-CNRS-UPMC,Paris,France),andJulieMeyer(LIMSI,CNRS,Universit(cid:3)eParis-Saclay,Paris,France)
Aspartofthe850-yearanniversaryofNotre-Damecathedral,Paris,therewasaspecialperformanceof“LaVierge.”Aclose-micre-
cordingoftheconcertwasmadebytheConservatoiredeParis.Inanattempttoprovideanewtypeofexperience,avirtualrecreationof
theperformanceusingtheseroughly45audiochannelswasmadeviaauralization.Acomputationalacousticmodelwascreatedandcali-
bratedbasedonin-situmeasurementsforreverberationandclarityparameters.Aperceptualstudywithomnidirectionalsourceandbin-
aural receiver validated the calibrated simulation for the tested subjective attributes of reverberation, clarity, source distance, tonal
balance,coloration,plausibility,ASW,andLEVwhencomparedtomeasuredresponses.Instrumentdirectivitywasincludedforeach
track’s representative orchestral section based on published data. Higher-Order Ambisonic (3rd order) RIRs were generated for all
sourceandreceivercombinationsusingtheCATT-AcousticTUCTsoftware.Virtualnavigationthroughoutavisual3Drenderingofthe
cathedralduringtheconcertwasmadepossibleusinganimmersiverenderingarchitecturewithBlenderVR,MaxMSP,andOculusRift
HMD.Wepresentmajorelementsofthisproject:calibration,perceptualstudy,systemarchitecture,lessonslearned,andtechnological
limitsencounteredwithregardstosuchanambitiousundertaking.[PreviouslypresentedinpartatEuroRegio2016&FISM2016.]
11:00
1aAAb2.Bidirectionalsoundtransport.ChunxiaoCao,ZhongRen(StateKeyLabofCAD&CG,ZhejiangUniv.,423Mengminwei
Bldg.,ZijingangCampus,ZhejiangUniversity,866YuhangtangRd.,Hangzhou310058,China,[email protected]),CarlSchissler,
DineshManocha(Univ.ofNorthCarolinaatChapelHill,ChapelHill,NC),andKunZhou(StateKeyLabofCAD&CG,Zhejiang
Univ.,Hangzhou,China)
Wepresentanewsoundpropagationalgorithm,BidirectionalSoundTransport(BST),basedonbidirectionalpathtracing.Current
state-of-the-artgeometricacousticmethodhandlesdiffusereflectionbybackwardpathtracingandusesdiffuseraintoimprovethevalid-
ityofgeneratedpaths.Weshowthatthiscanbeviewedasaspecialcaseofbidirectionalpathtracing.Byallowingtheconnectionstobe
establishedbetween any nodes of the subpaths,we are able to improve the samplingquality when sound sources locate near scene
objects.Thisensuresmorestablerenderingqualityandeasesraybudgetselection.Weproposeanewmetricbasedonthesignal-to-noise
(SNR)oftheenergyresponsetoevaluatetheperformanceofMonte-Carlopathtracingmethodforsound.Basedonthemetric,wede-
velopaniterativealgorithmtoredistributethesamplesamongbouncenumbersaccordingtothestatisticcharacteristicsofthesampling
ofpreviousframes.Weshowthatthesampleredistributionalgorithmconvergesandbetterbalancesbetweenearlyandlatereverbera-
tion.Weevaluateourapproachondifferentbenchmarksanddemonstratesignificantspeedupoverpriorgeometricacousticalgorithms.
Wealsodiscussclusteringalgorithmsusedtoimprovethescalabilityforbidirectionalsoundtransport.
3454 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3454
11:20
1aAAb3. Efficient construction of the spatial room impulse response. Carl Schissler (Comput. Sci., Univ. of North Carolina at
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ChapelHill,ChapelHill,NC),PeterStirling(Oculus,Seattle,WA),andRavishMehra(Oculus,8747148thAve.NE,Redmond,WA
A
98052,[email protected])
N.
Animportantcomponentofthemodelingofsoundpropagationforvirtualreality(VR)isthespatializationoftheroomimpulse U
response(RIR)fordirectionallisteners.Thisinvolvesconvolutionofthelistener’shead-relatedtransferfunction(HRTF)withtheRIR S
togenerateaspatialroomimpulseresponse(SRIR)whichcanbeusedtoauralizethesoundenteringthelistener’searcanals.Previous a
1
approachestendtoevaluatetheHRTFforeachsoundpropagationpath,thoughthisistooslowforinteractiveVRlatencyrequirements.
WepresentanewtechniqueforcomputationoftheSRIRthatperformstheconvolutionwiththeHRTFinthesphericalharmonic(SH)
domainforRIRpartitionsofafixedlength.Themaincontributionisanovelperceptuallydrivenmetricthatadaptivelydeterminesthe
lowestSHorderrequiredforeachpartitiontoresultinnoperceptibleerrorintheSRIR.ByusinglowerSHorderforsomepartitions,
ourtechniquesavesasignificantamountofcomputationandisalmostanorderofmagnitudefasterthanthepreviousapproach.Wecom-
paredthesubjectiveimpactofthisnewmethodtothepreviousoneandobserveastrongscene-dependentpreferenceforourtechnique.
Asaresult,ourmethodisthefirstthatcancomputehigh-qualityspatialsoundfortheentireimpulseresponsefastenoughtomeetthe
audiolatencyrequirementsofinteractivevirtualrealityapplications.
11:40
1aAAb4.Triton:Practicalpre-computedsoundpropagationforgamesandvirtualreality.NikunjRaghuvanshi(MicrosoftRes.,1
MicrosoftWay,Redmond,WA98052,[email protected]),JohnTennant(TheCoalitionStudio,MicrosoftCanada,Vancouver,BC,
Canada),andJohnSnyder(MicrosoftRes.,Redmond,WA)
Tritonisapre-computedwave-basedacousticssystemrecentlyshippedinthegame“GearsofWar4.”GamesandVRpresentexcit-
ingnewopportunitiesforvirtualacousticsbyprovidingtheplayerwithscene-dependentreverberationcuesandconveyinginformation
aboutvisuallyoccludedareas. Severaltechnicalchallenges must bemet. Scenescontainingmillionsof polygons arecommon,with
mixedindoor-outdoorspaceslikebrokenbuildings,courtyards,caves,androcks.Aviabletechniquemusthandlethiscomplexvisualge-
ometrywithoutusers’intervention.Theemphasisisonensuringtheresultingauralizationisperceptuallyconvincing,varyingsmoothly
onsourceandlistenermotioninsuchscenes.Highlyoccludedcaseswithsalientpathsundergoingmultipleedge-diffractionandscatter-
ingarecommon.Computationalrequirementsarequitestringent.AfractionofasingleCPUcoremustbeusedforacousticcalculations
formanytensofmovingsources.WediscusshowthesechallengesshapeTriton’sdesign.Pre-computationisusedtominimizeruntime
cost.Wavesimulationprovidescompleteautomationforcomplexscenegeometry.Theproducedfieldscontainbillionsofresponsesthat
taketerabytesofmemory.Akeycontributioniscompactencodingofthisdatainlessthanhundredmegabytes:objectiveroomacoustic
parametersareapproachedfromanovelperspectivetoaidinspatialcompression.Theresultingparametricframeworkisfastandpracti-
calforcurrentgamesandVRapplications.Videodemonstrationswillbeshown.
12:00
1aAAb5.Graphicalprocessingunits(GPU)-acceleratedacousticsimulationforinteractiveexperiences.TonyScudiero(NVIDIA,
4363HamiltonDr.,Eagan,MN55123,[email protected])
Theimportanceofincorporatingacousticeffectstothequalityofimmersioninvirtualrealityexperienceshasbeenthesubjectof
considerableattentionrecentlyduetoaresurgenceofinterestinvirtualreality.Thisworkdiscussesadvantagesandchallengesofusing
graphicalprocessingunits(GPU)inreal-timeray-basedacousticsimulationsforinteractiveapplications,especiallyvirtualreality.Exist-
ingray-tracinglibrariessuchasNVIDIA’sOptiXlibrarycanbeusedtocreateinteractive-timesimulationswhichcanbeappliedto
audioforvirtualrealityexperiencesandgames.Thisworkadditionallydiscussessomeofthechallengespresentincreatinganaccessible
librarywhichaimstoallownon-expertstoeasilymakeuseofacousticsimulationstoenhanceauditoryimmersioninnewvirtualreality
experiencesandgames.
3455 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3455
SUNDAYMORNING,25JUNE2017 ROOM206,10:40A.M.TO12:20P.M.
Session1aAAc
ArchitecturalAcoustics:TeachingandLearninginHealthyandComfortableClassroomsI
AriannaAstolfi,Cochair
PolitecnicodiTorino,CorsoDucadegliAbruzzi,24,Turin10124,Italy
VivekaLyberg-A˚hlander,Cochair
ClinicalSciences,Lund,Logopedics,PhoniatricsandAudiology,LundUniversity,ScaniaUniversityHospital,
LundS-22185,Sweden
DavidS.Woolworth,Cochair
OxfordAcoustics,356CR102,Oxford,MS38655
InvitedPapers
10:40
1aAAc1.Activelearninginmodernschools.MarkkuLang(FacultyofEducation,Univ.ofOulu,Kaitov€ayl€a7,Oulu,Oulu90570,
Finland,markku.lang@oulu.fi)
Weknowthatworldischangingandinnearfutureworkforceisgoingtobemoreindependent,contingentandtemporary.Therefore
futurelearningenvironmentsandlearningactivitiesareessentialtoprepareallstudentsforthechallengesofworkandlife.Finland
startedthisschoolyearwithanewcorecurriculumforbasiceducation,whichisfocusingondevelopingfutureskills(developingthe
keycompetencesasitisdescribedincurriculum).Totrainandtodevelopfutureskillsinschoolsnewmethods,learninglandscapesand
activitiesareneeded.FutureClassroomNetwork(EuropeanSchoolnet)isusingactivitiesasaguidelineforcreatingLearningZones.
TheseactivitiesandLearningzonesaresupportingkeyfutureskills:CriticalThinking—InvestigateCreativity—CreateCollaboration—
ExchangeLearningtolearn—DevelopDigitalcompetences—InteractCommunication—PresentButhowdothesefuturelearningactivities
lookandsoundlike?Whatareteachersandstudentsdoing,whentheyaretrainingFutureskills?Howschooldesignshouldrespectit?
11:00
1aAAc2.Theeffectofdifferentacousticaltreatmentinaclassroom.ErlingNilsson(Saint-GobainEcophon,Box500,HyllingeSE-
26061,Sweden,[email protected])
Acommonroomacousticmeasureinclassroomsandothercommonpublicspacesisasuspendedsoundabsorbingceiling.However,
theacousticalconditionintheclassroomnotonlydependsonthesuspendedceiling.Thesizeandshapeoftheroomaswellastheprop-
ertiesofbuildingmaterialandtheinteriorfittingsandfurniturewillalsoaffecttheroomacousticalconditions.Anothercircumstanceis
thenon-fulfillmentoftheconditionsfortheclassicdiffusefieldtheoryinroomswithabsorbentceilingtreatmentduetothenon-uniform
distributionoftheabsorbingmaterial.Thismakesthecalculationofroomacousticparametersmorecomplex.Thispaperaddressesthe
effectofdifferentfactorsthatareofimportancefortheacousticalconditionsinaclassroom.Outgoingfromtheunfurnishedclassroom
withoutsuspendedceilingtheeffectofintroducingasuspendedceiling,addingfurniture,addingwallpanels,aswellasextralowfre-
quencyabsorptionwillbeexemplifiedbasedonmeasurementsinafullscaleclassroom.Theroomacousticparametersthatareanalyzed
arethereverberationtimeT ,theSpeechClarityC andtheSoundStrengthG.Acalculationmodeladaptedforthenon-diffusecondi-
20 50
tionsinroomswithceilingtreatmentwillbebrieflymentioned.
11:20
1aAAc3.Optimalclassroomacousticdesignwithsoundabsorptionanddiffusionfortheenhancementofspeechintelligibility.
Giuseppina E. Puglisi, Filippo Bolognesi, Louena Shtrepi (Dept. of Energy, Politecnico di Torino, Torino, Italy), Anna Warzybok,
BirgerKollmeier(MedizinischePhysikandClusterofExcellenceHearing4All,CarlvonOssietzkyUniversit€atOldenburg,Oldenburg,
Germany), and Arianna Astolfi (Dept. of Energy, Politecnico di Torino, Corso DC degli Abruzzi, 24, Turin 10124, Italy, arianna.
astolfi@polito.it)
Classroomdesignshouldbefocusedontheenhancementoftheacousticcomfortforstudentsandteachers.Longreverberationtimes
andexcessivenoiselevelscanraisevocaleffortandnegativelyaffectspeechintelligibility.Recentstudiesandstandardsupdateshave
investigatedwhetheracoustictreatmentshouldincludebothabsorbentanddiffusivesurfacestoaccountfortheteachingandlearning
premisesatthesametime;however,studiesunderrealisticconditionsfortheimprovementofexistingclassroomsacousticsarestill
needed.Inthiswork,anexistingItalianclassroomwithpooracousticswasconsidered.Severalsolutionsfortreatmentweresimulated
usingCATT-AcousticsVR,includingadjustmentoftheabsorptionandscatteringcoefficientsofsurfacesdifferentlyconfiguredtoreach
optimalreverberationtime,andtoincreaseSpeechTransmissionIndexandDefinition,especiallyforthepositionsinthefurthestraw.
The effectiveness of the acoustic treatment was also evaluated in terms of enhancement of speech intelligibility using the Binaural
3456 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3456
SpeechIntelligibilityModel(Renniesetal.,2013).Itsoutcomesaregivenasspeechreceptionthresholdstoyieldafixedlevelofspeech
intelligibility.Modelpredictionsindictedanimprovementinspeechreceptionthresholdsupto6.8dBaftertheacousticintervention.
M
11:40 A
N.
1aAAc4.Goodacousticsforteachingandlearning.JonasChristensson(Saint-GobainEcophon,St.GobainEcophonAB,Box500,
U
Hyllinge26503,Sweden,[email protected]) S
a
Itisimportantthatclassroomsprovidegoodspeechintelligibilityandspeakcomfort.Beingabletolistenwithouteffortisimportant 1
forlearningandweknowthatpoorroomacousticsisaburdenthatimpedeslearningandaffectteachers’voicehealth.Agoodclassroom
istheSwedishforestswherewecancommunicateoverlongdistanceswithouthavingtoraiseourvoice.Ihavemadeseverallistening
testsinforestsandalsomeasuredthesoundreflectionsindifferentforests.TheresultsareinterestingandImeanthat“forestacoustics”
shouldbethegoalintermsofacousticconditionsinourschools.Manynationalsoundstandardsputrequirementsonroomacousticsin
classrooms.Onerequirementisreverberationtime,accordingtoISO3382-2,anditisoftenevaluatedwithT Unfortunately,thisisa
20.
verybluntmeasure,becausewestartT -evaluationfirstafterthesoundpressureleveldropped5dB.This“waitingtime”isoftenquite
20
longanditisaproblembecausewemissalotofimportantinformationfromtheearlypartofthedecaycurve.Therefore,Imeanwe
havetoaddC accordingtoISO3382-1,tocontroliftheroomacousticsisgoodenoughforteaching.
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12:00
1aAAc5. Classroom acoustics and children’s speech perception. Lori Leibold (Ctr. for Hearing Res., Boys Town National Res.
Hospital,555North30thSt.,Omaha,NE68124,[email protected]),RyanW.McCreery(Audiol.,BoysTownNationalRes.
Hospital,Omaha,NE),andEmilyBuss(Otolaryngology/HeadandNeckSurgery,Univ.ofNorthCarolina,ChapelHIll,NC)
Childrenmustlearninclassroomsthatcontainmultiplesourcesofcompetingsounds.Whiletherearenationalstandardsaimedat
creatingclassroomenvironmentsthatoptimizespeechintelligibility(e.g.,ANSI/ASA2010),thesestandardsarevoluntaryandmany
unoccupiedclassroomsfailtomeettheacceptablelevelsspecified.Moreover,littleattentionhasbeengiventomeasuringandunder-
standingeffectsofcompetingspeechonchildren’sperformanceintheclassroom.Datawillbepresentedthatdescribetypicalnoiselev-
elsintheclassroom.Resultsfromexperimentsinvestigatingtheconsequencesofcompetingnoiseandspeechonspeechperceptionat
different time points during childhood will be presented. Findings from experiments investigating potential benefits associated with
manipulatingacousticcuesthoughttoaidinseparatingtargetfrombackgroundspeechwillalsobediscussed.
SUNDAYMORNING,25JUNE2017 ROOM310,10:35A.M.TO11:40A.M.
Session1aAO
AcousticalOceanography:AcousticalOceanographyPrizeLecture
JohnA.Colosi,Chair
DepartmentofOceanography,NavalPostgraduateSchool,833DyerRoad,Monterey,CA93943
Chair’sIntroduction—10:35
InvitedPaper
10:40
1aAO1.Exploringoceanecosystemsanddynamicsthroughsound.JenniferL.Miksis-Olds(SchoolofMarineSci.&OceanEng.,
Univ.ofNewHampshire,24ColovosRd.,Durham,NC03824,[email protected])
Acousticsignalspropagatelongdistancesintheoceanandprovideameansformarinelifeandhumanstogaininformationabout
theenvironmentandformarineanimalstoexchangecriticalinformation.Innovationinunderwateracoustictechnologynowpermitsthe
remotemonitoringofmarinelifeandtheenvironmentwithouttheneedtorelyonhumanobservers,thephysicalpresenceofanobserva-
tionvessel,oradequatevisibilityandsamplingconditions.Passiverecordingsoftheunderwatersoundscapeprovideinformationtobet-
terunderstandtheinfluenceofenvironmentalparametersonlocalacousticprocesses,toassesshabitatqualityandhealth,andtobetter
understandtherisksofoceannoiseonmarinelife.Activeacoustictechnologyprovidesahigh-resolutionmeasureofbiologicaland
physicaloceanographicprocessesthroughtimeseriesofbackscattermeasurements.Theabilitytoobtainpassiveandactiveacoustic
measurements contemporaneously, along with ancillary data to validate and enhance interpretations, is a powerful tool facilitating
insightintooceanandecosystemdynamics.Knowledgegainedandquestionsraisedfromtheintegrationofacousticandoceanographic
datainrapidlychangingenvironmentswillbeshared,alongwithapreviewoftheAtlanticDeepwaterEcosystemObservatoryNetwork
(ADEON)programbeinglaunchedofftheSouthAtlanticOuterContinentalShelf.
3457 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3457
SUNDAYMORNING,25JUNE2017 BALLROOMB,10:40A.M.TO12:00P.M.
Session1aBAa
BiomedicalAcoustics:BeamformingandImageGuidedTherapyI:Algorithms
CostasArvanitis,Cochair
MechanicalEngineeringandBiomedicalEngineering,GeorgiaInstituteofTechnology,901AtlanticDr.NW,Room4100Q,
Atlanta,GA30318
ConstantinCoussios,Cochair
InstituteofBiomedicalEngineering,DepartmentofEngineeringScience,UniversityofOxford,OldRoadCampusResearch
Building,OxfordOX37DQ,UnitedKingdom
InvitedPaper
10:40
1aBAa1.Frequency-domainpassivecavitationimaging.KevinJ.Haworth(Univ.ofCincinnati,231AlbertSabinWay,CVC3940,
Cincinnati,OH45209,[email protected]),KennethB.Bader(Radiology,Univ.ofChicago,Chicago,IL),KyleT.Rich,Christy
K.Holland,andT.DouglasMast(Univ.ofCincinnati,Cincinnati,OH)
Apfel’sthreegoldenrules(knowthysoundfield,knowthyliquid,andknowwhensomethinghappens)shouldbeconsideredwhen
monitoringacousticcavitation-basedultrasoundtherapies.Thethirdruleisoftenfollowedusingpassivecavitationdetectionwithasin-
gle-elementtransducer.However,therapyguidancedemandsmonitoringcavitationactivityintheentiretissuevolumeofinterest.Using
array-basedpassivecavitationdetectionwithappropriatebeamforming,mapsofcavitationactivitycanbesuperimposedonpulse-echo,
grayscaleimagesoftissueanatomy.Inthistalk,wewilldiscussoneapproachforgeneratingcavitationactivitymaps,frequency-domain
passivecavitationimaging(FD-PCI).FD-PCIimplementsadelay,sum,andintegratealgorithm,whichwillbedescribedconceptually
andmathematically.Theadvantagesandlimitationsofthealgorithmwillbediscussedinthecontextofexamples.AdvantagesofFD-
PCIincludetheinnatefrequencyselectivityofthealgorithm,theabilitytouseparallelcomputingforincreasedprocessingspeed,thein-
dependenceoftheimageresolutionfromthetherapyinsonationpulseshape,andtheabilitytoquantifytheacousticpowerofemissions
detectedbythearray.Challengesofthealgorithmwillalsobediscussed,includingpooraxialresolutionandlimitationsofestimating
theemittedacousticpower.
ContributedPapers
11:00 provide the necessary improvement in PAM spatial resolution required in
severalclinicallyrelevantsituations,whereasinglearrayisusedandthera-
1aBAa2.Optimalbeamformingusinghigherorderstatisticsforpassive
tioofdepthtoaperturebecomeslarge.
acoustic mapping. Erasmia Lyka, Christian Coviello, and Constantin
Coussios(Dept.ofEng.Sci.,Inst.ofBiomedicalEng.,Univ.ofOxford,Old
11:20
Rd.CampusRes.Bldg.,Headington,OxfordOX37DQ,UnitedKingdom,
[email protected]) 1aBAa3. Attenuation estimation using passive acoustic mapping.
MichaelGrayandConstantinCoussios(Inst.ofBiomedicalEng.,Univ.of
PassiveAcousticMapping(PAM)ofsourcesofnonlinearacousticemis-
Oxford,OxfordOX37DQ,UnitedKingdom,[email protected])
sionshasbeenextensivelyinvestigatedformonitoringultrasoundtherapies.
Optimal data-adaptive beamforming algorithms, such as Robust Capon Passive acoustic mapping (PAM) techniques have been developed in
Beamformer(RCB),werereadilyproposedasameansofimprovingsource ordertoreduceriskandimprovetreatmentefficacybylocalizingandquan-
localization,accountingsimultaneouslyforarrayconfigurationandcalibra- tifyingcavitationemissionsduringtherapeuticultrasoundprocedures.The
tionerrors.RCB,however,assumesthatsignalsamplesfollowaGaussian performanceofthesetechniquesmaybesignificantlydegradedbyattenua-
distribution.AimingatimprovingthespatialresolutionofPAM,especially tionbetweentheinternaltherapeutictargetandtheexternalmonitoringsys-
in the axial direction with respect to the array, we propose an alternative tem. Attenuation itself is an essential parameter in the determination of
beamforming approach, Robust Beamforming by Linear Programming therapeuticoutcomesandsafetyoftreatmentssuchasHIFUablationorvol-
(RLPB).Thismethodmakesnoassumptionsonthestatisticaldistributionof umetric hyperthermia. However, the spatial and temporal distributions of
the received signals, and exploits not only the variance but also higher- this parameter are not typically known in clinical scenarios. To address
order-statistics (HOS) of the received signals. Performance evaluation on these challenges, we present a method for estimating attenuation using
simulatedandinvitroexperimentaldatasuggestsimprovementinspatialre- broadbandcavitationemissions,potentiallyallowingforrestorationofPAM
solutionontheorderof20%and15%intheaxialandtransversedirections performance,improvedtreatmentmonitoringandguidance,andmappingof
respectively.Thisfacilitatesreal-timemappingofdisjointcavitatingregions tissueattenuationoverthecourseofatreatment.Resultsfromsimulations
over biologically relevant lengthscales on the order of 2 mm in the axial andflowphantomexperimentsillustrate:(1)theimpactofsofttissue-like
direction. It is expected that the proposed beamforming approach will attenuation on PAM images, (2) the ability to estimate attenuation from
3458 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3458
cavitationdata,and(3)theenhancementofcavitationsourceimagingand spectrum(AS)method,afastplanarprojectionmethod,toperformpassive
energyestimationfollowingPAMinputdataattenuationcompensation.In acousticmappingofmicrobubblesthroughanintactskull.Finite-difference
thefuture,thetechniquecouldbeexpandedasageneralbroadbandmethod time-domainnumericalsimulationswereusedtomodelmicrobubbleemis- M
ofattenuationcorrectionforconventionaldiagnosticultrasoundimagesand sions’propagationthroughhomogeneous,stratified,and2Dinhomogeneous A
improvedtherapeuticultrasoundtreatmentplanning. (skull) environments approximately 80 mm by 160 mm. Reconstructions N.
with the AS approach were performed with constant and effective sound U
11:40 speeds,as wellas withmulti-steppropagation, to evaluate their abilityto S
correct for induced aberrations and localize the microbubbles. We also a
1aBAa4. Passive acoustic mapping in aberrating media with the 1
investigatedtheimpactofthereceiverpositiononthelocalizationaccuracy.
angularspectrumapproach.ScottJ.Schoen(Mech.Eng.,GeorgiaInst.of
Results for skull simulations indicated that the multi-step AS method
Technol.,10,000BurnetRd.,Austin,TX78758,[email protected])
reducedtheerrorinaxiallocalizationofthemicrobubblesbyontheorder
andCostasArvanitis(Mech.Eng.,GeorgiaInst.ofTechnol.,Boston,MA)
of50%comparedwiththeeffectivesoundspeedmethod,whileincurring
Theabilitytolocalizeandcharacterizeultrasound-inducedmicrobubble approximatelya25%increaseincomputationtimeforeachdoublingofthe
oscillationsthroughtheintactskullwithhighspatialandtemporalresolu- numberofpropagationsteps.BothASmethodswereseveralordersofmag-
tionholdssignificantpromiseforthediagnosisandtreatmentofbraindis- nitudefasterthantime-domainreconstruction.Furtherinvestigationofthe
eases and disorders. In this study, we investigated the ability of angular potentialofthisapproachtocorrectskullaberrationsiswarranted.
SUNDAYMORNING,25JUNE2017 ROOM312,10:40A.M.TO12:20P.M.
Session1aBAb
BiomedicalAcoustics:ImagingI
ParagV.Chitnis,Chair
DepartmentofBioengineering,GeorgeMasonUniversity,4400UniversityDrive,1G5,Fairfax,VA22032
ContributedPapers
10:40 ofparticlesinatissuemimickingphantomusinganovellongworkingdis-
tanceconfocalmicroscopethatenablesparticledistributionstobemeasured
1aBAb1. Ultrasound enhanced delivery of cisplatin loaded
insituandinrealtime.
nanoparticles. Richard J. Browning, Shuning Bian (Dept. of Eng. Sci.,
Univ. of Oxford, BUBBL, IBME, ORCRB, Oxford OX3 7DQ, United
11:00
Kingdom, [email protected]), Philip J. Reardon (Div. of
BioMater. and Tissue Eng., UCL Eastman Dental Inst., Univ. College 1aBAb2. Optimizing gold nanorod volume for minimum cell toxicity
London,London,UnitedKingdom),MaryamParhizkar(Mech.Eng.,Univ. andmaximumphotoacousticresponse.OscarB.Knights,DavidCowell
CollegeLondon,London,UnitedKingdom),AnthonyH.Harker(Dept.of (SchoolofElectron.&Elec.Eng.,Univ.ofLeeds,LeedsLS29JT,United
Phys. & Astronomy, Univ. College London, London, United Kingdom), Kingdom, [email protected]), James R. McLaughlan (Div. of Biomedical
Vessela Vassileva (Dept. of Oncology, Univ. College London, London, Imaging, Univ. of Leeds, Leeds, United Kingdom), and Steven Freear
United Kingdom), Dan Daly (Lein Appl. Diagnostics, Reading, United (School of Electron. & Elec. Eng., Univ. of Leeds, Leeds, United
Kingdom),BarbaraR.Pedley(Dept.ofOncology,Univ.CollegeLondon, Kingdom)
London,UnitedKingdom),MohanEdirisinghe(Mech.Eng.,Univ.College
Plasmonic nanoparticles show great potential for molecular-targeted
London, London, United Kingdom), Jonathan C. Knowles (Div. of
photoacoustic(PA)imaging.Tomaximizelightabsorption,thegoldnano-
BioMater. and Tissue Eng., UCL Eastman Dental Inst., Univ. College
rods (AuNRs) are illuminated at their surface plasmon resonance (SPR),
London, London, United Kingdom), and Eleanor P. Stride (Dept. of Eng.
which for biomedical application is typically in the “optical window” of
Sci.,Univ.ofOxford,Oxford,UnitedKingdom)
700-900nm.ForAuNRs,oneofthemainfactorsthatdeterminestheSPRis
Cisplatinformsthebasisformanychemotherapyregimens,howeverthe theiraspectratio.Sinceitispossibletohaveasimilaraspectratio,butdif-
maximumpermissibledoseislimitedbyitssystemictoxicity.Nanoencap- ferentsizeoftheparticlethechoiceofparticlecouldhaveacriticaleffect
sulationofdrugshasbeenshowntoreduceoff-targetsideeffectsandcan onanumberoffactors,suchasphotoacousticemissions,celltoxicity,and
potentiallyimprovetreatmentburdenonpatients.However,uptakeofnano- therapeuticefficacy.Forexample,aparticularsizedAuNRmayproducea
formulationsattumorsitesisminimalwithoutsomeformofactivedelivery. higher PA response, for an equivalent laser fluence, but be more toxic to
Wehavedevelopedasubmicron,polymericnanoparticlebasedonbiocom- cellpopulations.Inthisstudy,thePAresponseofAuNRswithfourdifferent
patible and degradable poly(lactic-co-glycolic acid) (PLGA) capable of volumesbutsimilaraspectratios(~4)arecompared.Alinearrelationship
encapsulatingcisplatinandwhichcanbeboundtothesurfaceofaphospho- betweenincidentlaserfluenceandPAamplitudeisshownandresultsindi-
lipidcoatedmicrobubble.Theacousticbehaviorandstabilityoftheresult- cate that AuNRs with larger volumes produce stronger PA emissions. In-
ing nanoparticle loaded microbubbles will be compared with those of vitrocellstudieswereperformedonalungcancercelllinetoassessthecell
unloadedmicrobubbles.Resultswillalsobepresentedontheextravasation toxicityofthedifferentsizedAuNRsviaacolorimetryassay.
3459 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3459
11:20 gatedonlywhentheinitialmechanicalimpulsewasgreaterthanacertain
threshold. In fact, the impulse then propagated as a solitary shock wave
1aBAb3. Ultrasound-mediated blood-brain barrier disruption:
causing local adiabatic phase transition of the lipid molecules along the
Correlation with acoustic emissions. Miles M. Aron, Lester Barnsley,
way.Althoughthephenomenonhasbeenobservedhereinpurelipidmono-
ShamitShrivastava(Dept.ofEng.Sci.,Univ.ofOxford,OldRd.Campus
layers,whichrepresentawell-documentedmodelforbiologicalmembranes,
Res. Bldg.,IBME,Roosevelt Dr.,Oxford,Oxfordshire OX37DQ,United
theoriginoftheobservedphenomenonliesintheconservationoftheen-
Kingdom, [email protected]), Marinke Van der Helm, Loes
tropyoftheinterface,determinedbythechangeinstateoftheinterfacedur-
Segerink (Facultyof Elec. Eng.,Mathematicsand Comput.Sci., Univ. of
ing the impulse. Given that the state diagrams of biological membranes
Twente,Enschede,Netherlands),andEleanorP.Stride(Dept.ofEng.Sci.,
have nonlinearities near physiological conditions, nonlinear sound waves
Univ.ofOxford,Oxford,UnitedKingdom)
areexpectedtobefundamentallyinvolvedininterandintracellularcom-
Blood-brain barrier (BBB) disruption mediated by ultrasound and munication.Indeed,theobservedacousticphenomenonischaracteristically
microbubbles(US-BBBD)isapromisingstrategyfornon-invasiveandtar- similartonerveimpulses.
geteddeliveryoftherapeuticstothebrain.InUS-BBBD,treatmentcontrol
12:00
isachievedbyexternallymonitoringacousticemissions(AE)andadjusting
ultrasound parameters in real-time to avoid AE associated with damage. 1aBAb5. Focus ultrasound for augmenting convection-enhanced
RecentworksuggeststhatAEmayalsoprovideinsightregardingtheextent deliveryofnanoparticlesinthebrain.AliMohammadabadi(Diagnostic
ofBBBopeningandBBBrecoverytime.ThemechanismsunderlyingBBB RadiologyandNuclearMedicine,Univ.ofMarylandSchoolofMedicine,
openingandrecovery,however,arelargelynotunderstood.Toinvestigate 110 S. Paca St., Rm. 104, Baltimore, MD 21201, ali.mohammadabadi@
US-BBBDmechanismswithregardtoAE,wedevelopedaninvitroplat- umm.edu), David S. Hersh (Neurosurgery, Univ. of Maryland School of
formformonitoringbothBBBintegrityandAEduringUS-BBBD.Tempo- Medicine,Baltimore,MD),PavlosAnastasiadis(DiagnosticRadiologyand
rallyresolvedBBBintegritymonitoringwasachievedusingamicrofluidic NuclearMedicine,Univ.ofMarylandSchoolofMedicine,Baltimore,MD),
BBB-on-a-chipdevicewithintegratedtrans-endothelialelectricalresistance PhilipSmith,GraemeF.Woodworth,AnthonyJ.Kim(Neurosurgery,Univ.
(TEER) measurements. Well-characterized ultrasound exposure and AE of Maryland School of Medicine, Baltimore, MD), and Victor Frenkel
monitoring were achieved using a focally aligned high-intensity focused (DiagnosticRadiologyandNuclearMedicine,Univ.ofMarylandSchoolof
ultrasoundtransducerandpassivecavitationdetector.Inadditiontorecord- Medicine,Baltimore,MD)
ingTEERandAEdata,ourplatformiscompatiblewithfluorescencemi-
croscopy during ultrasound exposure, providing further insight into US- Wepreviouslydemonstratedhowultrasoundcanenhancethedispersion
BBBD mechanisms. This work further demonstrates potential for in vitro of locally administrated nanoparticles withinthe extracellular/perivascular
screening of cavitation agents and/or therapeutics for novel US-BBBD spacesintheexvivobrainbynon-destructivelyenlargingtheseregions.The
applicationsandstrategies. current study aimed to translate these results in vivo, where custom, non-
adheringbrain-penetratingnanoparticles(BPN:60,200,and500nm),were
11:40 administereddirectlyintothebrainsofSpragueDawleyratsbyconvection-
enhanceddelivery.Non-invasive,transcranialfocusedultrasound(TCFUS)
1aBAb4. Nonlinear propagation of two dimensional sound waves
wascarriedoutusinganMRI-guidedsystem(1.5MHz,10mspulses,10%
observedatlipidinterfaces.ShamitShrivastava(Univ.ofOxford,OldRd.
dutycycle,and2.3MPa).15individualexposuresina3(cid:2)5matrix(spac-
Campus Res. Bldg., Oxford OX3 7DQ, United Kingdom, shamit.
ing:1.5mm)inonehemisphereweregiven,wherethesizeofthefocalzone
[email protected]) and Matthias F. Schneider (Medizinische und
(-6dB)was1(cid:2)1X8mm.At2hrspost-treatmentbrainswereharvested
biologischePhysik,TechnischeUniversitat,Dortmund,Germany)
andsectioned,withdigitalimagescapturedandprocessedusingacustom
Experimental resultsarepresentedontheacousticpropagationof me- MATLABscript.Thisinvolvedthe“Otsu”thresholdingmethod,basedon
chanical perturbations in a lipid monolayer along the air-water interface. gray level histograms and threshold determinations for maximizing the
Theinterfacewasexcitedbyapiezo-cantilever,andpropagatingimpulses interclassvariance.Asexpected,BPNdistributionsinthenon-treatedbrains
weremeasuredopticallyusingForsterResonanceEnergyTransfer(FRET). decreasedwithanincreaseindiameter.PretreatingwithTCFUSwasfound
Thevelocityofpropagationvariedfrom0.1to1m/sdependingonthecom- tosignificantlyincreasethedistributionofthe200nmBPNs.Theseresults
pressibilityoftheinterface.Nearanonlinearityinthestatediagramofthe havebroadimplicationsfortherapeuticdeliveryforavarietyofbraindis-
interface,forexample,nearaphasetransitionofthelipids,impulsespropa- easesanddisorders.
3460 J.Acoust.Soc.Am.,Vol.141,No.5,Pt.2,May2017 Acoustics’17Boston 3460