Terms used in the following discussions may be unfamiliar. Some of the
more important ones are defined below.

Amplitude
   The height of a waveform, which corresponds to the amount of voltage or
   current in the electronic circuit.

Amplitude modulation
   A means of producing special audio effects by using one channel to alter
   the amplitude of another.

Channel
   One "unit" of the audio device.

Cycle
   One repetition of a waveform.

Frequency
   The number of times per second a cycle repeats.

Frequency modulation
   A means of producing special audio effects by using one channel to
   affect the period of the waveform produced by another channel.

Period
   The time elapsed between the output of successive sound samples,
    in units of system clock ticks.

Precedence
   Priority of the user of a sound channel.

Sample
   Unit of audio data, one of the fixed-interval points on the waveform.

Waveform
   Graph that shows a model of how the amplitude of a sound varies over
   time-usually over one cycle.