Re: [AUDITORY] Localizing smoke detectors - why is it so hard?

["Jennifer M. Groh" <jmgroh@xxxxxxxx>]

Dear Leslie and List,

A clarification - perceptually, I am usually not confused that the sound 
must be coming from the ceiling.   Admittedly, that is probably based on 
prior knowledge. Once I have started looking for which smoke detector is 
going off, the elevation problem is off the table because I can be 
looking right at it (i.e. with my head tilted back so that the sound is 
actually straight ahead in a head-centered frame of reference) and still 
not be sure that it is coming from the smoke detector I am looking at 
versus one in a totally different room in the house.

I'm curious - is this only an issue with American smoke detectors?  If 
so, that would be a clue.  Perhaps smoke detectors in other parts of the 
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 - people are generally better at localisation in azimuth horizontally than at altitude…
>
> --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 quite puzzled about: why it is so hard to localize a smoke detector when its battery starts to fail?  Here is what I have considered so far:
> >
> > - To my ear, the chirp sounds high frequency enough that ILD cues should 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 dynamic feedback, i.e. changes in ITD and ILD as the head turns during a sound.   However, in my laboratory we have obtained excellent sound localization performance in head-restrained monkeys and human subjects localizing sounds that are briefer than the reaction time to make an orienting movement.
> >
> > - An additional possibility is that we have too little experience with such sounds to have assembled a mental template of the spectrum at the source, 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 together 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@xxxxxxxxxxxxx
> Tel (44) 1786 467435 Fax (44) 1786 464551
> www http://www.cs.stir.ac.uk/~lss/

--
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