In the absence of a SIGNAL, the NOISE which comprises all interference, including HUM and HISS, in a system which stores, reproduces or measures sound. Its level is measured by the SIGNAL-TO-NOISE RATIO. The term is also used colloquially to denote AMBIENCE.
See: COMPRESSION, DUBBING, DYNAMIC RANGE, GAUSSIAN NOISE, RANDOM NOISE, RUSTLE NOISE, WHITE NOISE. Compare: KEYNOTE SOUND, LO-FI, SILENCE.