Re: [AUDITORY] Localizing smoke detectors - why is it so hard? ("Jennifer M. Groh" )


Subject: Re: [AUDITORY] Localizing smoke detectors - why is it so hard?
From:    "Jennifer M. Groh"  <jmgroh@xxxxxxxx>
Date:    Tue, 25 Jun 2013 06:13:14 -0400
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

Dear Leslie and List, A clarification - perceptually, I am usually not confused that the sound=20 must be coming from the ceiling. Admittedly, that is probably based on=20 prior knowledge. Once I have started looking for which smoke detector is=20 going off, the elevation problem is off the table because I can be=20 looking right at it (i.e. with my head tilted back so that the sound is=20 actually straight ahead in a head-centered frame of reference) and still=20 not be sure that it is coming from the smoke detector I am looking at=20 versus one in a totally different room in the house. I'm curious - is this only an issue with American smoke detectors? If=20 so, that would be a clue. Perhaps smoke detectors in other parts of the=20 world have different types of dead-battery warning sounds. Best wishes, --Jennifer On 6/25/2013 5:40 AM, Leslie Smith wrote: > I wonder if the fact that it's above your head makes a difference - peo= ple are generally better at localisation in azimuth horizontally than at = altitude=85 > > --Leslie Smith > > On 25 Jun 2013, at 09:46, Jennifer M. Groh wrote: > >> Dear List, >> >> I am writing a book for a general audience on how the brain processes = spatial information ("Making Space"). The chapter on hearing covers many = topics in sound localization, but there is one that I'm currently still q= uite puzzled about: why it is so hard to localize a smoke detector when i= ts battery starts to fail? Here is what I have considered so far: >> >> - To my ear, the chirp sounds high frequency enough that ILD cues shou= ld be reasonably large. >> >> - At the same time, it seems to have a broad enough bandwidth, and in = any case it has onset-and-offset cues, that ITD cues should be usable. >> >> - A possibility is that the chirp is too brief, and that limits dynami= c feedback, i.e. changes in ITD and ILD as the head turns during a sound.= However, in my laboratory we have obtained excellent sound localizatio= n performance in head-restrained monkeys and human subjects localizing so= unds that are briefer than the reaction time to make an orienting movemen= t. >> >> - An additional possibility is that we have too little experience with= such sounds to have assembled a mental template of the spectrum at the s= ource, so that spectral cues are of less use than is normally the case. >> >> I'm leaning towards a combination of the last two factors, which toget= her would render the cone of confusion unresolved for these stimuli. >> >> Thoughts? >> >> Best wishes, >> >> --Jennifer Groh >> >> -- >> Jennifer M. Groh, Ph.D. >> >> Professor >> Department of Psychology and Neuroscience >> Department of Neurobiology >> Center for Cognitive Neuroscience >> >> >> B203 LSRC, Box 90999 >> Durham, NC 27708 >> >> 919-681-6536 >> www.duke.edu/~jmgroh > > Professor Leslie S. Smith B.Sc. Ph.D. SMIEEE, > Head, Institute of Computing Science and Mathematics, School of Natural= Sciences > University of Stirling, > Stirling FK9 4LA, Scotland > l.s.smith@xxxxxxxx > Tel (44) 1786 467435 Fax (44) 1786 464551 > www http://www.cs.stir.ac.uk/~lss/ > > > > > > > --=20 Jennifer M. Groh, Ph.D. Professor Department of Psychology and Neuroscience Department of Neurobiology Center for Cognitive Neuroscience B203 LSRC, Box 90999 Durham, NC 27708 919-681-6536 www.duke.edu/~jmgroh


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