SV: bite bar and bone conduction

[Stefan Stenfelt <stefan.stenfelt@xxxxxxxxxx>]

Christian,

I did an experiment looking at sensitivity stimulating by bone conduction
via the teeth. There is also a JASA publication on transmission of BC sound
via the teeth. In my investigation we found the sensitivity for stimulating
at the teeth to be similar to that exciting BC at the skin covered mastoid.
However, the sensitivity depends on the mass of the bite bar, i.e. a heavier
bite bar yields lower sensitivity at the high frequencies (acting as a
low-pass filter).

Although not investigated explicitly, we did not se any variation of the
sensitivity with bite pressure. However, the measurement time was important
since the subjects fatigued after some time and it was difficult to maintain
enough bite pressure.

Look at
Stenfelt and Håkansson, Scand Audiol, 1999, 28(3):190-8
Dahlin et al, JASA, 1973, 53:1434-7     

//Stefan

Stefan Stenfelt, Technical Audiologi,+46 13 222856 

-----Ursprungligt meddelande-----
Från: AUDITORY - Research in Auditory Perception
[mailto:AUDITORY@xxxxxxxxxxxxxxx] För Christian Kaernbach
Skickat: den 13 september 2007 22:26
Till: AUDITORY@xxxxxxxxxxxxxxx
Ämne: bite bar and bone conduction

Dear List,

We plan to do experiments involving bite bars and bone conduction. We 
could use normal bone conduction transducers strapped to the mastoid but 
it might be compelling to apply the sound via the bite bar. Has anybody 
experience with sound application through bite bars? I have found in the 
internet that potential users of BAHA (bone anchored hearing aids) are 
encouraged to test the effect of bone conduction sound via bite bars. It 
could be that bite bar sound transmission will be variable depending on 
bite pressure. We will use bite bars with dental impressions. Hopefully 
these will ensure a good contact so that sound transmission should not 
depend too much on bite pressure. A five-dB variability would be 
acceptable. ... And what about the sound transmission to the table? Can 
it be ignored? Would mounting the bite bar to the table make it more 
difficult to apply sounds via the bite bar?

Thanks in advance,
Christian

-- 
Prof. Dr. Christian Kaernbach
Allgemeine Psychologie
Institut für Psychologie
Christian-Albrechts-Universität zu Kiel
Olshausenstr. 62
D-24098 Kiel
Germany
www.kaernbach.de