[ubuntu-uk] sound issues - fixed

Andrew Oakley Andrew.Oakley at hesa.ac.uk
Thu Mar 26 10:13:57 GMT 2009

Paul Sutton wrote:
> Looks like i have fixed it,  pcm volume was down, (what ever pcm is)

PCM is Pulse Code Modulation, the main method for describing sound
samples. Imagine plotting a sound wave on a chart, then every N
microseconds you take a measurement of how high or low the wave is at
that point. The points are called "pulses" and the measurements are
called "codes".

PCM is used for all sampled sound, which these days is almost all played
back sound from a PC. Depending on the implementation, MIDI GM sounds
may or may not be controlled via PCM. For example, a card which
implements MIDI GM sounds in software will almost certainly use PCM,
whereas a card which implements MIDI GM sounds in hardware might not.


Andrew Oakley
Head of Software Development
Higher Education Statistics Agency (HESA)
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