hearing aids

David Kastrup dak at rama.informatik.rwth-aachen.de
Thu Mar 23 03:44:41 EST 1995

sirianni at uts.cc.utexas.edu (Jeffrey Sirianni) writes:

>I'm not sure what the Multifocus does with the 2 microphone signals, but
>I wonder if they are using the info to cross-correlate and remove redundant
>info (i.e. noise).  I just read through the Brey, R.H. et al. (1987) article
>which used a 2 microphone set-up with LSM (Least Mean Squares) adaptive
>filtering.  I'm wondering if the same approach has been applied directed onto
>a wearable aid?  Any info would be appreciated....

This is very improbable. For the background noise suppression techniques
using two microphones, correlation measures are used. This depends on
environmental and background noise to have less correlation between
microphones. Putting a head between the microphones helps, but placing
two microphones apart just slightly will not achieve much, although
different directional characteristics might indeed cause less coherence
with ambient noise.

I'd think that one microphone being directional they'd just switch between
microphones on demand (like the original post suggested).
David Kastrup, Goethestr. 20, D-52064 Aachen        Tel: +49-241-72419
  Email: dak at pool.informatik.rwth-aachen.de         Fax: +49-241-79502

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