[linux-audio-user] Create high-pitch noises like the mosquito device

[Erik de Castro Lopo]

listreader wrote:

> I saw the mosquito device that will annoy younger
> people, but not older people:
>  http://www.compoundsecurity.co.uk/teenage_control_products.html
> 
> Its pretty expensive.  How would I begin to create that
> from scratch?  Can a sound-card generate those frequencies?

Yes, the frequencies are in the range 18kHz to 20kHz. Obviously
you need to choose a sample rate on the sound card which can
reproduce these frequencies, ie 44.1kHz or above.

> I imagine I would need a special speaker.

Standard tweeters from a standard stereo should reproduce them just
fine.

> How about an amp?, does that also need to transmit the
> higher freqs.?

Any decent amplifier should do it.

> Whats good software in linux to generate certain frequencies?

It should be easy to create these sounds using Csound, Supercollider,
Pd, or in fact any of the many, many soft synths available for Linux.
 
Erik
-- 
+-----------------------------------------------------------+
  Erik de Castro Lopo
+-----------------------------------------------------------+
"I invented the term Object-Oriented, and I can tell you I
did not have C++ in mind." -- Alan Kay