Science of Sound: 4. Measuring Frequency

See what’s happening!

Sound waves have a pattern that repeats itself. Each repeat is said to be one cycle. Frequency is a measure of how quickly the wave repeats itself. It is commonly measured in hertz (Hz) — the number of cycles completed in one second. For example, a wave that cycles 5 times per second is said to have a frequency of 5 Hz.

Cycles

Frequency: the number of complete wave cycles per second (Hz). Each color in the illustration at right represents one complete cycle of a sound wave.

If a sound has a frequency of 2000 Hz, how many times do the tuning fork tines move away from and back to the start position in one second?