TONEGEN for making nice noises...

Another quick and dirty C hack that will generate tones on your /dev/dsp device.
tonegen: Generates a sine wave on the sound card or standard out.
   -a dB       Sets attenuation from "all ones" in dB.  Default is "0 db".
   -d device   Sets device name.  Default is "/dev/dspW".
               If "device" is "-" then it uses STDOUT
   -f Hz       Sets tone in Hertz.  Default is "400 Hz".
   -r rate     Sets device sample rate in Hertz.  Default is "44100 Hz".
   -t seconds  Sets time to run.  Default is infinite.
               The length of the tone will run over slightly until full
               cycle stops at a "zero crossing" to prevent clicks.