S/N ratio (SNR: Signal to Noise Ratio)
The S/N ratio, one of the measures of signal transmission quality, expresses the signal/noise ratio in decibels . The larger this value, the higher the transmission quality. The S/N ratio is used as one of the reproduction characteristics of recording media such as magnetic tapes, magnetic discs, and optical discs. For example, a cassette tape has an S/N ratio of approximately 50 dB (signal voltage is 300 times the noise voltage), and a CD has an S/N ratio of approximately 100 dB (signal voltage is 100,000 times as large as the noise voltage).