harmonic (n.)

In ACOUSTIC PHONETICS, a regular (PERIODIC) waveform accompanying a FUNDAMENTAL FREQUENCY, which helps to identify a complex TONE; also called an overtone. Harmonics are whole-number multiples of the fundamental frequency; for example, if the fundamental is 200 Hz, the harmonics will be at 400 Hz, 600 Hz, and so on. The harmonics are numbered in sequence, and in phonetics the numbering starts with the fundamental: in this example, 200 Hz would be the ‘first harmonic’, 400 Hz the ‘second harmonic’ (the ‘first overtone’) and so on. The combination of a fundamental frequency and the AMPLITUDE of its various harmonics combine to give a sound its characteristic tone and quality. It should be noted that, in music, the first harmonic is traditionally regarded as the first multiple of the fundamental, so that (in the above example) 400 Hz would be the ‘first harmonic’.