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From: wmartin@brl-tgr.ARPA (Will Martin )
Newsgroups: net.med,net.info-terms,net.audio
Subject: "Ultrasonic" hearing
Message-ID: <1280@brl-tgr.ARPA>
Date: Mon, 6-Jan-86 13:55:29 EST
Article-I.D.: brl-tgr.1280
Posted: Mon Jan  6 13:55:29 1986
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In article <1260@brl-tgr.ARPA> gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) writes:
>By the way, the fellow who got headaches in the room full of burning-in
>monitor assemblies was probably being affected by the near-ultrasonic
>sound generated by the horizontal circuits (often transformer laminations
>vibrating).  Even if he didn't consciously hear them, such whistles would
>lead to irritability and headaches.

For what it's worth, the latest issue (#28, I think) of The $ensible Sound,
an "underground" audio magazine, has a report of a recent study which
found that people could *really* hear up to 40 kHz, not the
previously-believed 20 kHz limit. The older studies, according to the
item, used transducers to reproduce the high-frequency sounds which were
defective or inferior, masking the higher frequencies in distortion.

There was no reference or citation; I wonder if some of the net.med
people can locate the real study this item was based on, and post a
reference or bibliographic note? This sort of info might be used to
force terminal designers to finally eliminate all that nasty high-pitched
noise their products emit!

Will