Sound Analyser

A machine comprised of a filter system and a system for indicating the relative energy passed through each part of the filter. This measurement gives the distribution of energy of the applied signal as a function of frequency called the spectrum of the signal.

See: Sonography, Spectrograph. Compare: Fourier Analysis, Helmholtz Resonator, Level Recorder, Oscilloscope, Sound Level Meter.

There are many types of analysers. An Octave Band Analyser measures the intensity level for each of a set of octave bands, centred on 31.5, 63, 125, 250, 500, 1000, 2000, 4000, 8000 and 16,000 Hz. A Third-Octave Band Analyser divides the frequency spectrum into three bands per octave, the Tenth-Octave Band Analyser into ten bands per octave.

See Broad Band Noise, Infrasonic, Spectrum, White Noise for examples of third-octave analyses. See: Centre Frequency. Compare: Critical Band, Appendix E.

Other types of analysers include the Wave Analyser, which is a continuously variable analyser over the entire audio range; the Impact Noise Analyser for analysing impact sounds such as hammers or punch presses; and the Vibration Analyser, for analysing infrasonic vibration.

Standard Octave Band Frequencies

Centre Frequencies for Third-Octive Bands