Chapter | twenty-six
In the analysis of sound, it has always been important to be able to describe the frequency content of a signal. The traditional method is to use a filter bank, containing a number of filters with relative bandwidths, for example 1/1 octave, 1/2 octave, 1/3 octave, or perhaps with narrower bandwidths depending on the purpose. The signal being filtered passes through one filter at a time. Once the signal for a filter has been detected and its value read or printed, the next filter is reviewed.
A more practical variant is the parallel analyzer, where each filter has its own detector. With this, the values can be read simultaneously in all frequency ...