Re: Bite-induced pitch shift?

[Bob Masta <masta@xxxxxxxxx>]

Tom:

A resonance change shouldn't change any frequencies, only their amplitudes.
So if that were the cause of losing the beats, it would have to be such a severe
(anti) resonance that one of the two beating components went below your detection
threshold.  This wouldn't be my first guess.  Piano tones are pretty complex...
I wonder if the results would be clearer with pure tones, say from a flute
or whistle (including puckered-lips whistle), which are close to sine waves.
A bench or sound card oscillator would be even better.

Curious problem!




On 11 Jul 03, at 5:06, Thomas G Brennan wrote:

> In part, it may have to do with perceived resonation properties.  I tend to
> suspect that the major cause is tightening of the eardrum and alteration to the
> size of the outer and middle ear spaces.  Since I wrote my original response to
> this question I have done a few experiments with a piano.  As a tuner I have
> experimented with hearing beats while setting a tempered octive.  When clenching
> my jaw I tend to either completely lose the beats I can normally hear or they
> sound as though they have nothing to do with the actually notes usually being
> far faster than would be expected for the pitch change.
>
> Tom
>
>
> Tom Brennan KD5VIJ, CCC-A/SLP R/D - AU
> web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html
>
> On Wed, 9 Jul 2003, Bob Masta wrote:
>
> > Date: Wed, 09 Jul 2003 08:47:45 -0400
> > From: Bob Masta <masta@UMICH.EDU>
> > To: AUDITORY@LISTS.MCGILL.CA
> > Subject: Re: Bite-induced pitch shift?
> >
> > Tom:
> >
> > Thanks for your observations on pitch shift.  I'm curious why a shape
> > change of the external auditory canal should be implicated.  Does
> > this effect only apply to broadband signals, such that changing the
> > canal's resonant frequency might give a "formant" change in the
> > spectral shape?  I can't see how it could change the pitch of a
> > pure tone, unless the basilar membrane is also deformed somehow.
> >
> > .
> >
> >
> > On 8 Jul 03, at 17:42, Thomas G Brennan wrote:
> >
> > > I neglected to say that this seems to be caused by alteration to the shape
> > > and/or position of the external auditory canal by the mandibular condyle.
> > >
> > > Tom
> > >
> > >
> > > Tom Brennan KD5VIJ, CCC-A/SLP R/D - AU
> > > web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html
> >
> >
> > Robert Masta
> > tech@daqarta.com
> >
> >          D A Q A R T A
> > Data AcQuisition And Real-Time Analysis
> >  Shareware from Interstellar Research
> >         www.daqarta.com
> >


Robert Masta
tech@daqarta.com

         D A Q A R T A
Data AcQuisition And Real-Time Analysis
 Shareware from Interstellar Research
        www.daqarta.com