- The number of times something is repeated. In acoustics, it refers to the number of complete sound waves that pass a given point in a given time. Usually measured in Hertz (one cycle per second). Typically refers to the pitch of a sound, how high or low it is. The higher the number, the higher the pitch. Source: Church Audio & Acoustics Glossary
- For a function periodic in time, the reciprocal of the period. Unit, hertz (Hz). Source: Glossary of Terms in Noise Control Engineering
- The measure of the rapidity of alterations of a periodic signal, expressed in cycles per second or Hz. Source: http://www.owenscorning.com/around/sound/glossary.asp
- The number of repeating corresponding points on a wave that pass a given observation point per unit time.