Posted by Bob on August 17, 2005
In Reply to: Signal-to-noise ratio posted by Bruce Kahl on August 15, 2005
: : What does the phrase "signal-to-noise ratio mean?
: Put very simply, the signal-to-noise ratio (SNR or S/N) measures the clarity of a signal.
: It refers to the amount of signal power that gets transmitted in digital communications compared with the amount of noise (unwanted signal interference) that accompanies the signal.
: A higher ratio indicates higher sound quality (less noise). Most transmission techniques try to minimize noise on the receiving end of the transmission.
: The terms "signal" and "noise" are also used in chat rooms and discussion groups to refer to "meaningful discourse" versus "worthless blather." Of course, the latter is always a subjective opinion.
The term predates digital. The first tape recorders and stereo receivers were measured many ways, one of which was signal to noise ratio. Old phonograph records had poor ratios: lots of pop and hiss and extraneous noise. Dolby noise reduction improved recorded sound a lot; more signal, less noise. Going digital was a huge leap forward in the fidelity of recordings ... today, the term is used much more as a metaphor. For example, if you are trying to get a message out to a wide audience (advertising, public relations, political message, whatever) you face huge difficulties because there is so much message pollution noise around. People are exposed constantly to advertising and signage and information overload. Getting your signal through all that noise is more challenging than ever.