Subject: Re: [AUDITORY] Localizing smoke detectors - why is it so hard? From: "Ewan A. Macpherson" <ewan.macpherson@xxxxxxxx> Date: Wed, 26 Jun 2013 16:52:49 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>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 EAM