|
Hi,
What you are describing is NOT a hearing loss related
problem - it is called "occlusion".
It is related to a hearing aid user having an occluded
(blocked) ear canal due to the presence of the hearing aid
plastics.
Low frequency sounds of the speaker's own voice and/or
eating of food (<500 Hz) travel via bone conduction and enter the cavity
between the hearing aid and eardrum. These trapped LF sounds cannot escape and
so can sound very loud to the hearing aid user.
Note that this problem only happens if the hearing aid
user has GOOD hearing at the low frequencies!
If the user has a hearing loss at low frequencies then
this occlusion effect is NOT noticed.
This is simply a problem of hearing aid usage, not hearing
loss.
Some hearing aids (or earmoulds) have holes ("vents")
drilled through them to let this LF sound escape in an attempt to reduce the
problem.
However this can then increase this risk of feedback
whistle.
Modern "open fitting" hearing aids such as the GN Resound
Air are specially designed to overcome this problem.
Perhaps increasing the gain of < 500Hz frequencies
via an equaliser would create the effect you seek?
(Creating the effect of hearing loss is a different
problem)
regards,
Richard
----- Original Message -----
Sent: Monday, February 13, 2006 6:21
PM
Subject: sound manipulations
Dear
List,
I am
writing to request information on a type of software or available program that
allows for signal manipulations that may approximate hearing impaired
listeners? descriptions of speech. As you know, one common complaint is
that people sound as if they are speaking in a barrel. Another is that
the speaker sounds as if he has a bucket over his head. Is anyone aware
of such a program?
Sincerely,
René H. Gifford, Ph. D.,
CCC-A
Postdoctoral
Fellow
Arizona State University
Department of Speech and Hearing
Science
P. O.
Box
870102
Tempe, AZ
85287-0102
Phone: (480) 965-4954
Mail
Code: 0102
rgifford@xxxxxxx
|