The characteristic ascribed to a variable which repeats any value it attains at regular intervals of time called a PERIOD; that is, it describes an OSCILLATION that passes repeatedly through maximum and minimum values at the same rate. Periodic WAVEFORMs have a PITCH associated with them.
Conversely, aperiodic waveforms have no such regularity or PERIODICITY and may have ambiguous pitch (see INHARMONIC) or may be classified as NOISE. See: BROAD BAND NOISE, RANDOM NOISE.
See: COMPLEX TONE, CYCLE, FOURIER ANALYSIS, FOURIER THEOREM, FREQUENCY, MODULATION, RHYTHM, SIMPLE HARMONIC MOTION.