Sound wave properties and characteristics

NOTE!

Sinusoidal waves of various frequencies; the bottom waves have higher frequencies than those above. The horizontal axis represents time.

Sound waves are often simplified to a description in terms ofsinusoidal plane waves, which are characterized by these generic properties:

• Frequency, or its inverse, the period
• Wavelength
• Wave number
• Amplitude
• Sound pressure
• Sound intensity
• Speed of sound
• Direction

Sound that is perceptible by humans has frequencies from about 20 Hz to 20,000 Hz. In air at standard temperature and pressure, the corresponding wavelengths of sound waves range from 17 m to 17 mm. Sometimes speed and direction are combined as a velocity vector; wave number and direction are combined as a wave vector.

Transverse waves, also known as shear waves, have the additional property, polarization, and are not a characteristic of sound waves.