acoustics

Wavelength


For any periodic wave the wavelength is the distance from a given point in the wave to the corresponding point in the next cycle of the wave, frequently represented by the Greek letter lambda (λ). It may also be thought of as the distance the sound travels in one cycle or period.

See: Diffraction, Doppler Effect, Eigenton, Oscillation, Parabolic Reflector, Reflection, Resonator, Sound Shadow, Sound Wave, Standing Waves, Ultrasonic.

The velocity v of sound (see speed of sound) in any medium equals the frequency f times the wavelength (v = f.λ). Similarly if the velocity and frequency are known, the wavelength may be determined by dividing the velocity by the frequency (λ = v / f). See chart below.

Some examples of the wavelengths of various frequencies are:

lowest audible C

16.4 Hz

69 feet

lowest C on piano

32.7 Hz

34 feet 6 inches

middle C on piano

261 Hz

4 feet 3 inches

violin A string

440 Hz

2 feet 6 inches

C four octaves above middle C

4,186 Hz

3.25 inches

highest audible tone

20,000 Hz

.68 inches

Scales for wavelength to frequency conversion for the speed of sound in air of 343 m/sec.