Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/5/84; site randvax.UUCP
Path: utzoo!watmath!clyde!cbosgd!ukma!psuvm.bitnet!psuvax1!burdvax!sdcrdcf!randvax!edhall
From: edhall@randvax.UUCP (Ed Hall)
Newsgroups: net.med,net.info-terms,net.audio
Subject: Re: "Ultrasonic" hearing
Message-ID: <2869@randvax.UUCP>
Date: Sun, 12-Jan-86 15:59:46 EST
Article-I.D.: randvax.2869
Posted: Sun Jan 12 15:59:46 1986
Date-Received: Wed, 15-Jan-86 00:35:24 EST
References: <1280@brl-tgr.ARPA> <652@ihlpm.UUCP>
Reply-To: edhall@rand-unix.UUCP (Ed Hall)
Distribution: net
Organization: Rand Corp., Santa Monica
Lines: 22
Xref: watmath net.med:3128 net.info-terms:798 net.audio:7129

>> 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

The fact is plausible, but the explanation is absurd.  Nonlinearities
in reproduction may add harmonics to the acoustic signal, and for
an especially bad transducer might even excite resonances at sub-
harmonics of the test frequency.  But if an appropriate amount of
acoustic power is being generated at the test frequency, anything
masking it would have to be as least as audible.

As a personal note, at 31 I'm still bothered by TV and terminal
horizontal frequencies--but not as much.  It's one of the benifits
of getting older...

                -Ed Hall
                ihnp4!sdcrdcf!randvax!edhall