Subject: Auditory Spatial Stream Segregation From: Imran Dhamani <imrandhamani@xxxxxxxx> Date: Wed, 31 Mar 2010 20:07:29 +0530 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--0-1493304939-1270046249=:16037 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Dear All, =A0 =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 I was looking for a task to assess spatia= l auditory stream segregation=A0 (sequential stream segregation based on lo= calization and/or lateralization cues) in literature and found an experimen= t done by=A0Judd T.(1979):(Spatial stream segregation in The Journal of the= Acoustical Society of America=A01979;65(S1):S122 - S122). According to him= =A0when the tones of a slow (e.g., 1 tone/s) tone sequence alternate betwee= n widely placed speakers, observers report hearing a single melody which mo= ves back and forth between the speakers like a pingpong game. When the same= sequence is presented more rapidly (e.g., 8 tones/s), observers report hea= ring two independent melodies or streams, one from each speaker (Spatial St= ream Segregation). The other studies that I found to study spatial stream s= egregation were those which used presentation of multitalker babble or othe= r noise through two or three loudspeakers in free field and then present a = target speech stimulus (word/sentence) through any one speaker the position of wh= ich can or cannot be known by the listener, the task of the listener is to = identify the target correctly in presence of the spatial noise. I tried sim= ulating the experiment by Judd using slow and fast alternating tones betwee= n two widely placed speakers, although I could hear the galloping like/ping= pong like rhythm for the slow tone presentation but then could not actuall= y get the split stream percept (I am comparing these percepts to the typica= l sequential stream segregated percepts based on fundamental frequency or o= ther strong spectral or temporal=A0cues, especially the primitive stream se= gregation percepts as demostrated by Bregman and colleagues)=A0=A0in the fa= ster tone presentations. I could not get access to the entire study or arti= cle as it was just the online abstract which was available.=A0I was wonderi= ng =A0if this task is really efficient to assess spatial auditory stream segregation. Moreover I also wanted any suggestions regarding any differen= ce in efficacy of assessment of stream segregation if the target positions = for presentations of target speech stimuli are same or different on each pr= esentation, and if the target position is either known/predictable or unpre= dictable by the listener. Also in this task will roving the noise/babble ac= ross different speakers (eg. speakers 3,4,5 for the first trial and speaker= 6, 7, 8 for the next trial) will give any addtional information regarding = auditory stream segregation ? I would also request everyone to share if any= other tasks that would be more efficient or appropriate to assess the spat= ial stream segregation ability.=A0 =A0 Best Regards, Imran Dhamani PhD. Student (Audiology). =A0 $$$$$ monty@xxxxxxxx@xxxxxxxx@xxxxxxxx@xxxxxxxx=0A=0A=0A The INTERNET now has a personality. YOURS! Se= e your Yahoo! Homepage. http://in.yahoo.com/ --0-1493304939-1270046249=:16037 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable <table cellspacing=3D"0" cellpadding=3D"0" border=3D"0" ><tr><td valign=3D"= top" style=3D"font: inherit;"><DIV>Dear All,</DIV> <DIV> </DIV> <P align=3Dleft>  = ; I was looking for a task to assess spatial auditory stream segregat= ion (sequential stream segregation based on localization and/or later= alization cues) in literature and found an experiment done by <SPAN>Ju= dd T.(<SPAN id=3Dctl00_MainContent_pubYearTxt>1979)</SPAN>:(Spatial stream = segregation in </SPAN><SPAN id=3Dctl00_MainContent_journalTxt>The Journal o= f the Acoustical Society of America</SPAN> <SPAN id=3Dctl00_MainConten= t_pubYearTxt2>1979</SPAN>;<SPAN id=3Dctl00_MainContent_volumeTxt>65</SPAN>(= <SPAN id=3Dctl00_MainContent_issueTxt>S1</SPAN>):<SPAN id=3Dctl00_MainConte= nt_paginationTxt>S122 - S122)</SPAN>. According to him w<SPAN id=3Dctl= 00_MainContent_abstractTxt>hen the tones of a slow (e.g., 1 tone/s) tone se= quence alternate between widely placed speakers, observers report hearing a= single melody which moves back and forth between the speakers like a pingp= ong game. When the same sequence is presented more rapidly (e.g., 8 tones/s), observ= ers report hearing two independent melodies or streams, one from each speak= er (Spatial Stream Segregation). The other studies that I found to study sp= atial stream segregation were those which used presentation of multitalker = babble or other noise through two or three loudspeakers in free field and t= hen present a target speech stimulus (word/sentence) through any one speake= r the position of which can or cannot be known by the listener, the task of= the listener is to identify the target correctly in presence of the spatia= l noise. I tried simulating the experiment by Judd using slow and fast alte= rnating tones between two widely placed speakers, although I could hear the= galloping like/ping pong like rhythm for the slow tone presentation but th= en could not actually get the split stream percept (I am comparing these pe= rcepts to the typical sequential stream segregated percepts based on fundamental frequency or other strong spectral or temporal cues, espe= cially the primitive stream segregation percepts as demostrated by Bregman = and colleagues) in the faster tone presentations. I could not ge= t access to the entire study or article as it was just the online abstract = which was available. I was wondering if this task is really effi= cient to assess spatial auditory stream segregation. Moreover I also wanted= any suggestions regarding any difference in efficacy of assessment of stre= am segregation if the target positions for presentations of target speech s= timuli are same or different on each presentation, and if the target positi= on is either known/predictable or unpredictable by the listener. Also in th= is task will roving the noise/babble across different speakers (eg. speaker= s 3,4,5 for the first trial and speaker 6, 7, 8 for the next trial) will gi= ve any addtional information regarding auditory stream segregation ? I would also request everyone to share if any other tasks that would be mo= re efficient or appropriate to assess the spatial stream segregation abilit= y. </SPAN></DIV> <DIV><SPAN></SPAN> </DIV> <DIV><SPAN>Best Regards,</SPAN></DIV> <DIV><SPAN>Imran Dhamani</SPAN></DIV> <DIV><SPAN>PhD. Student (Audiology).</SPAN></DIV> <DIV><SPAN> </SPAN><BR>$$$$$ monty@xxxxxxxx@xxxxxxxx@xxxxxxxx@xxxxxxxx</DIV></td></tr></table><br>=0A = <!--1--><hr size=3D1></hr> =0AYour Mail works best with the New Yahoo = Optimized IE8. <a href=3D"http://in.rd.yahoo.com/tagline_ie8_new/*http://do= wnloads.yahoo.com/in/internetexplorer/" target=3D"_blank">Get it NOW!</a>. --0-1493304939-1270046249=:16037--