Real time measurement of tone content of noise - averaging successive maxima and minima to derive tone amplitude and frequency

摘要

The noise to be analysed is received by microphone, amplified and fed to two circuits. One circuit detects the successive maxima and minima of the fine structure and generates corres. timing pulses. The second circuit uses these pulses to sample the signal and convert the samples to digital form. Each successive pair of samples is averaged and placed in a store at a position corres. to the time of occurrence. The store is scanned to locate the positions of maxima and minima. The difference between max. and min. stored values gives the amplitude, and the number of store cells between them gives the frequency, of a tone component of the noise. The method may also be used as the basis of a computer program.