Re: [AUDITORY] Localizing smoke detectors - why is it so hard? ("Richard F. Lyon" )


Subject: Re: [AUDITORY] Localizing smoke detectors - why is it so hard?
From:    "Richard F. Lyon"  <dicklyon@xxxxxxxx>
Date:    Thu, 27 Jun 2013 22:21:25 -0700
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

--089e0158be44d8000a04e0300c34 Content-Type: text/plain; charset=ISO-8859-1 Pierre, yes, those are good recent papers. But the basic idea of ITD at high frequencies goes way back. As McFadden and Pasanen (1976) say, based on bands of noise and two-tone signals, "In many conditions of listening, sensitivity to interaural time differences at high frequencies compares favorably with sensitivity at low frequencies--good performance requires only tens of microseconds of interaural time delay." (McFadden, D. and Pasanen, E. G. (1976). "Lateralization at high frequencies based on interaural time differ- ences", The Journal of the Acoustical Society of America 59, 634-639.) Dick ps. Their introduction lists older observations, and comments on how they tend to get ignored in the face of the duplex theory that works only with tones and narrowband signals; it is a good reminder for us now: Recently Henning (1974a, 1974b) remade a point that badly needed to be remade. He showed once again that the auditory system can utilize interaural time differ- ences to lateralize at high frequencies when the wave- forms are complex. The same fact had previously been demonstrated by David, Guttman, and van Bergeijk (1959), Leakey, Sayers, and Cherry (1958), Klumpp and Eady (1956), Tobias and Schubert (1959), and oth- ers, but many of us concerned with binaural processing had been ignoring these data and had come to think solely in terms of the so-called duplex theory of sound localization. This widely cited theory asserts that the auditory system uses interaural time differences to localize only for frequencies below about 1200-1500 Hz, and that at higher frequencies it can only use the gradu- ally increasing interaural level differences. But as Henning (1974a, 1974b) showed, and as we shall further demonstrate here, time-delayed complex waveforms at high frequencies can be lateralized just as accurately as time-deiayed low-frequency waveforms. The im- plication is that with complex waveforms the auditory system is able to process the ongoing interaural time differences present in the fluctuating envelope. The problem with the duplex theory, then, is that it was based solely on localization and lateralization research employing pure tones, and thus, is concerned only with cycle-by-cycle differences in the fine structure of the waveform. And while the theory is true enough for such waveforms, it is almost totally irrelevant, for it cannot be appropriately generalized to real-world situ- atious involving complex waveforms. On Thu, Jun 27, 2013 at 9:41 PM, Pierre Divenyi <pdivenyi@xxxxxxxx > wrote: > You are right, Dick! A series of recent papers on "transposed AM sounds" > by Les Bernstein and Tino Trahiotis show very clearly that periodically > interrupted high-frequency carriers are localizable based on ITD. > -Pierre > > On 6/27/13 12:37 PM, "Richard F. Lyon" <dicklyon@xxxxxxxx> wrote: > > Ewan, thanks for your paper reference; very relevant. > > You wrote there, "ITD dominance is shown indirectly in findings that head > movements are highly effective for localizing low-frequency targets but not > narrow-band high-frequency targets." > > I agree. But it doesn't address what you could do with wide-band > high-frequency targets. If the alarms used 3 kHz, but chopped on and off, > with not such a high-Q resonance, they would probably have good enough > onsets to help you make use of ITD, yes? > > I often see people disregarding ITD as a powerful cue above 1 kHz or so; > but the basis for that is only that it's not a usable cue for sine waves > and other narrow-band signals. Wideband clicks and noises are easy to > localize, even if simulated with only ITD. > > Dick > > > > > On Wed, Jun 26, 2013 at 1:52 PM, Ewan A. Macpherson < > ewan.macpherson@xxxxxxxx> wrote: > >> Richard F. Lyon wrote, On 6/25/2013 1:43 PM: >> >> Jennifer, >>> >>> I believe the answer is primarily in the transducer: to make the beeper >>> cheep, they use a resonant transducer, which has a slow buildup at the >>> onset and makes the resulting signal not very broadband at all, >>> depriving you of all ITD cues. And they make the beeps so brief that >>> you don't have much chance to turn your head and vary the ILD cue; >>> >> >> It also turns out that front/back location is much more readily >> disambiguated by head turning in stimuli that carry low-frequency ITD than >> in those carrying only high-frequency ILD (such as the ~3-kHz, more-or-less >> pure tones from smoke detectors). The dynamic ILD cue does not seem to be >> able to beat the phantom spectral cue due to the narrow high-frequency peak >> in the spectrum. This is true under anechoic conditions, and presumably >> would be even worse in reverberation. >> >> http://asadl.org/poma/**resource/1/pmarcw/v19/i1/**p050131_s1<http://asadl.org/poma/resource/1/pmarcw/v19/i1/p050131_s1> >> >> EAM >> > > --089e0158be44d8000a04e0300c34 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div>Pierre, yes, those are good recent papers.=A0 But the= basic idea of ITD at high frequencies goes way back.=A0 As McFadden and Pasanen (1976) say, based on bands of noise and two-tone signals, &quot;In many conditions of= =20 listening, sensitivity to interaural time differences at high=20 frequencies compares favorably with sensitivity at low frequencies--good performance requires only tens of microseconds of interaural time=20 delay.&quot;<div class=3D"im"><br> (McFadden, D. and Pasanen, E. G. (1976). &quot;Lateralization at high frequ= encies based on interaural time differ-<br>ences&quot;, The Journal of the = Acoustical Society of America 59, 634-639.)<br><br></div></div>Dick<br> <br>ps. Their introduction lists older observations, and comments on how they tend= =20 to get ignored in the face of the duplex theory that works only with=20 tones and narrowband signals; it is a good reminder for us now:<br> <br>Recently Henning (1974a, 1974b) remade a point that <br>badly needed to= be remade. He showed once again that <br>the auditory system can utilize i= nteraural time differ- <br>ences to lateralize at high frequencies when the= wave- <br> forms are complex. The same fact had previously <br>been demonstrated by Da= vid, Guttman, and van Bergeijk <br>(1959), Leakey, Sayers, and Cherry (1958= ), Klumpp <br>and Eady (1956), Tobias and Schubert (1959), and oth- <br> ers, but many of us concerned with binaural processing <br>had been ignorin= g these data and had come to think <br>solely in terms of the so-called dup= lex theory of sound <br>localization. This widely cited theory asserts that= the <br> auditory system uses interaural time differences to <br>localize only for f= requencies below about 1200-1500 Hz, <br>and that at higher frequencies it = can only use the gradu- <br>ally increasing interaural level differences. B= ut as <br> Henning (1974a, 1974b) showed, and as we shall further <br>demonstrate here= , time-delayed complex waveforms at <br>high frequencies can be lateralized= just as accurately <br>as time-deiayed low-frequency waveforms. The im- <b= r> plication is that with complex waveforms the auditory <br>system is able to= process the ongoing interaural time <br>differences present in the fluctua= ting envelope. The <br>problem with the duplex theory, then, is that it was= <br> based solely on localization and lateralization research <br>employing pure= tones, and thus, is concerned only with <br>cycle-by-cycle differences in = the fine structure of the <br>waveform. And while the theory is true enough= for <br> such waveforms, it is almost totally irrelevant, for it <br>cannot be appro= priately generalized to real-world situ- <br>atious involving complex wavef= orms. <div class=3D""><div id=3D":3ir" class=3D"" tabindex=3D"0"><img class= =3D"" src=3D"https://mail.google.com/mail/u/0/images/cleardot.gif"></div> </div></div><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">O= n Thu, Jun 27, 2013 at 9:41 PM, Pierre Divenyi <span dir=3D"ltr">&lt;<a hre= f=3D"mailto:pdivenyi@xxxxxxxx" target=3D"_blank">pdivenyi@xxxxxxxx= tanford.edu</a>&gt;</span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p= x #ccc solid;padding-left:1ex"><div class=3D"HOEnZb"><div class=3D"h5"><div= style=3D"font-size:16px;font-family:Calibri,sans-serif;word-wrap:break-wor= d"><div> You are right, Dick! A series of recent papers on &quot;transposed AM sound= s&quot; by Les Bernstein and Tino Trahiotis show very clearly that periodic= ally interrupted high-frequency carriers are localizable based on ITD.</div= > <div>-Pierre</div><div><br></div><span><div><div>On 6/27/13 12:37 PM, &quot= ;Richard F. Lyon&quot; &lt;<a href=3D"mailto:dicklyon@xxxxxxxx" target=3D"_b= lank">dicklyon@xxxxxxxx</a>&gt; wrote:</div></div><div><br></div><div dir=3D= "ltr"> <div><div><div>Ewan, thanks for your paper reference; very relevant.<br><br= ></div>You wrote there, &quot;ITD dominance is shown indirectly in findings= that head movements are=20 highly effective for localizing low-frequency targets but not=20 narrow-band high-frequency targets.&quot;<br><br></div>I agree.=A0 But it d= oesn&#39;t address what you could do with wide-band high-frequency targets.= =A0 If the alarms used 3 kHz, but chopped on and off, with not such a high-= Q resonance, they would probably have good enough onsets to help you make u= se of ITD, yes?=A0 <br> <br></div><div>I often see people disregarding ITD as a powerful cue above = 1 kHz or so; but the basis for that is only that it&#39;s not a usable cue = for sine waves and other narrow-band signals.=A0 Wideband clicks and noises= are easy to localize, even if simulated with only ITD.<br> </div><div><br></div>Dick<br><br><div><div><br> </div></div></div><div clas= s=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On Wed, Jun 26, 2013 a= t 1:52 PM, Ewan A. Macpherson <span dir=3D"ltr">&lt;<a href=3D"mailto:ewan.= macpherson@xxxxxxxx" target=3D"_blank">ewan.macpherson@xxxxxxxx</a>&gt;= </span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p= x #ccc solid;padding-left:1ex">Richard F. Lyon wrote, On 6/25/2013 1:43 PM:= <div><br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;borde= r-left:1px #ccc solid;padding-left:1ex"> Jennifer,<br><br> I believe the answer is primarily in the transducer: =A0to make the beeper<= br> cheep, they use a resonant transducer, which has a slow buildup at the<br> onset and makes the resulting signal not very broadband at all,<br> depriving you of all ITD cues. =A0And they make the beeps so brief that<br> you don&#39;t have much chance to turn your head and vary the ILD cue;<br><= /blockquote><br></div> It also turns out that front/back location is much more readily disambiguat= ed by head turning in stimuli that carry low-frequency ITD than in those ca= rrying only high-frequency ILD (such as the ~3-kHz, more-or-less pure tones= from smoke detectors). The dynamic ILD cue does not seem to be able to bea= t the phantom spectral cue due to the narrow high-frequency peak in the spe= ctrum. This is true under anechoic conditions, and presumably would be even= worse in reverberation.<br> <br><a href=3D"http://asadl.org/poma/resource/1/pmarcw/v19/i1/p050131_s1" t= arget=3D"_blank">http://asadl.org/poma/<u></u>resource/1/pmarcw/v19/i1/<u><= /u>p050131_s1</a><span><font color=3D"#888888"><br><br> EAM<br></font></span></blockquote></div><br></div></span></div> </div></div></blockquote></div><br></div> --089e0158be44d8000a04e0300c34--


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