Actually some type of microwave device is being pointed directly at my
house. The high frequency sounds it produces are unbearable.Have you heard
of low pass and white noise filters ?Can they help in this regard ?
"Richard Norman" <rsnorman at mediaone.net> wrote in message
news:2Rxt6.11$QA3.3747 at typhoon.mw.mediaone.net...
> Is there some reason you want to block ultrasounds that you can't hear
> anyway? Is there some reason to believe that microwave ovens
> produce ultrasound frequencies?
>> I am just curious. In any event -- sound, like light, travels in
straight
> lines when
> considering distances much larger than the wavelength. Sound bends around
> objects (diffracts) if they are smaller than the wavelength.
>> So bass sounds (frequencies to several hundred Hz and wavelengths of
greater
> than 1 meter) tend to wrap around barriers, but very high frequency sounds
> (frequencies of 10kHz or so and wavelength of a few cm) are easily
shielded.
> Ultrasonics above 33kHz have wavelengths of less than 1 cm and so a simple
> styrofoam box will produce adequate shielding.
>> "Juliet" <juliet at cellucity.co.za> wrote in message
> news:995rvq$ltp$1 at ctb-nnrp2.saix.net...> > any suggestions how one can block ultrasound frequencies ?Is there an
item
> > on the market that can absorb or block high frequency sounds being
emitted
> > by microwave or other devices?
>>>
