From: firstname.lastname@example.org (Nico Coesel)
Subject: Re: Coming soon to a theatre near you - endless mischief potential
Date: Sat, 12 Oct 2002 20:41:13 GMT
NNTP-Posting-Date: Sat, 12 Oct 2002 20:42:56 +0000 (UTC)
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John Larkin wrote:
>On Sat, 12 Oct 2002 17:40:18 +0100, John Devereux
>>>On 12 Oct 2002 06:13:17 -0700, email@example.com (milne_v) wrote:
>>>>We've heard hypersonic sound. It could change everything.
>>>>by Suzanne Kantra Kirschner
>>>> It's the most promising audio advance in years, and it's coming this
>>>>fall: Hypersonic speakers, from American Technology (headed by the
>>>Total, silly nonsense. Air is not a nonlinear medium, at least at
>>You're probably right... but what about the inside of your
>I believe that eardrums are slightly nonlinear (I bet John W knows
>something about this) so might serve as a mixer/detector for very high
>levels of two-tone ultrasonics. But even 30 KHz is hard to make into a
>tightly directional beam (as in the lifeguard example) and the levels
>would certainly have to be high, certainly dangerous, to produce even
>a barely audible response. Besides, the invention claims that the
>sonics are created in air, and that the sonics are somehow confined by
>the ultrasonics, and doesn't lose volume for 150 yards. Stupidity.
>Popular Science prints this sort of impossible crap all the time.
No, it's certainly not impossible and far from crap! Ultrasonic sounds
can be heard through the bone behind your ear. This new (read: old and
already widely known by anyone professionally involved with audio)
technology is for example used in some type of hearing aid for
patients who's nerves to the ear are still intact.
One of my former colleagues once attended a demonstration of these
ultrasonic soundspots and he confirmed it worked.
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