On Sat, 25 May 1996 15:10:01 GMT, gmalf19 at nwlink.com (G. M. Alf)
>On 24 May 1996 09:22:50 -0700, sirianni at UTS.CC.UTEXAS.EDU ("Jeffrey G.
>>>Forwarded from ASHA Audiology Listserve
>>>>>Subject: Hearing Aid receiver
>>>Sender: owner-asha-aud-forum at postman.com>>>>>>The question was brought up tonight about a hearing aid that is advertised in
>>>birding magazines that is supposed to provide amplification up to 12K Hz. Has
>>>anyone heard about this? Any ideas on validity? Can an HA receiver actually put
>>>out much gain at 12K?
>>>Owner, Anywhere Audio
>>* Jeff Sirianni, M.A., CCC-A *
>>* Sound Advice / R.G. Delaney, M.D. *
>>* 710 Water Street / Suite 404 *
>>* Kerrville, TX 78028 *
>>I have driven hearing aid receivers well beyond 15k Hz with standard
>op amps and signal generators. This is useless as far as most
>conventional hearing aids go due to feedback, amplifier limits and the
>limited high frequency requirements of the user > 4k Hz. I would
>guess that the aid that is advertised in the birding magazine uses
>walkman type headphones along with conventional amps, mics and
>batteries rather than hearing aid components.
>Not necessarily true. With the proper selection of microphone and
receiver and the proper design of the acoustic system and electronics,
extended response hearing aids are not only possible but do exist. The
HiFi Kamp can easily have a response out to 16k and the majority of
the aids that I design go out past 10k. However, you must be careful
at how they are measured. If you go by just the standard ANSI 2cc data
you won't see it. They are measured using good real ear systems, or
simulated using Kemar.
Design Specialist Internet: dahotvet at mmm.com
3M Hearing Health Phone: 612-733-6350
3M Center 260-6A-18 Fax: 612-736-3892
St. Paul, MN 55144-1000
"Without deviation from the norm, there can be no progress"
Opinions expressed herein are my own and may not represent those of my employer.