A METHOD OF ICA IN TIME-FREQUENCY DOMAIN
AMETHODOFICAINTIME-FREQUENCYDOMAINShiroIkedaPRESTO,JSTHirosawa2-1,Wako,351-0198,JapanShiro.Ikeda@brain.riken.go.jpNoboruMurataRIKENBSINob oru.Murata@brain.rikABSTRACTWeprop oseametho dofICAforseparatingconvolu-tivemixturesofacousticsignals.Thesignalsrecordedinarealenvironmentarenotinstantaneousbutconvolutivemixtures,b ecauseofthedelayandreections.Inordertoseparatethesesignals,itisef-fectivetotransformthesignalsintime-frequencydo-main.Thedicultp ointintheseapproachesistheambiguityofthep ermutationandamplitudewhichisunavoidableinoriginalICAproblem.Sincetheba-sicICAapproachescannotsolvetheseambiguity,wneedanotherapproachtosolvethem.Wemployedtheenvelop esofsignalstosolveit,andhade-velop edsomealgorithms.Inthisarticle,weshotheoutlineofourorignalmetho d,andsomeextensionsit.Theyare,theon-lineversionandauditorysceneanalysisproblem.1.INTRODUCTIONOneofthego o dapplicationsICAisseparatingacousticsignalsrecordedinarealenvironment.Thisproblemiswellknownasthename,\co cktailpartyproblem".Whatisdicultfortheseproblemsthatthesignalsincludedelaysandreections(Fig.1).