Re: Woody Norris HyperSonic Sound speaker article

[Walter Knapp <>]

Dan Dugan wrote:
> I heard Bernie's demonstrations at the NSS workshop last summer, and 
> demonstrations at the NSCA show in Dallas last week. They used a 
> recording of water trickling, and the sound would seem to come from 
> any object the panel was pointed at. Really neat.
> 
> Detractors say the ultrasonic level is around 150 dB and gives people 
> headaches. What the effect of the ultrasonic sound would be on 
> wildlife is unknown.

What you have is a "bat jammer". It would be right in the range for the 
hunting calls of some bats.

Probably other animals not too happy either.

BTW, you get some of the same effect using magnaplane speakers. Not as 
precise. I have a set of magnaplanes in my living room, suspended from 
the high ceiling.

Walt




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