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From: vaso@mips.COM (Vaso Bovan)
Newsgroups: sci.electronics,sci.skeptic,alt.restaurants,misc.consumers.house,rec.audio,rec.pets,sci.bio
Subject: Ultrasonic Pest Repellers
Keywords: pest,fraud
Message-ID: <31929@buckaroo.mips.COM>
Date: 23 Nov 89 02:00:15 GMT
Lines: 23

This is about cockroaches, fleas, mice, and assorted pests founds on pets
and in restaurants.

There has been a lot of advertisement lately of "ultrasonic pest repellers."
these are devices which emit ultrasonic sound which is supposed to annoy
pests into leaving the pet/premises.

My understanding is that these devices are outright frauds. Videos showing
pests cowering in a corner of a glass box, as far away as they can get from
an "ultrasonic pest repeller," neglect to state the power output of the sonic
(ultrasonic ?) transducers.  At some high level, they surely "work" in the
sense of doing gross damage to hearing and other sensing mechanisms, but it
was my impression that commercial devices sold as "pest repellers" have
nowhere near the required power levels.

I wrote a letter to Consumer Reports Magazine to complain about the promotion
of these devices, and was surprised to get a letter back that "there was no
evidence they do *not* work." It seems to me the U.S. army did extensive
testing at least a decade ago and concluded the devices were useless. But I
don't remember the reference.

Does anyone know of the U.S. Army tests or other recent scientific tests on
these devices ?