The uses of sound waves

​​In a nutshell

Sound waves are pressure waves that are able to transfer energy between locations. Sound waves have many uses in everyday life including transferring information for conversion by electrical signals. 

Sound waves

Sound waves transfer energy between locations. They do this through vibrations of particles in the medium the wave travels through. No matter is transferred in this process. The amount of energy transferred by the wave depends on its frequency and wavelength. 

Sound waves are a type of pressure wave. Pressure waves transfer energy in the direction the wave is travelling in. This means pressure waves are always longitudinal. 

The diagram below shows a slinky modelled as a longitudinal wave. The arrow shows that the energy transfer is in the direction the longitudinal wave is travelling in. 

Ultrasound 

Ultrasound is a type of high frequency sound wave that humans cannot hear. This is because it is too high-pitched for the human ear to detect. It has the same properties as the sound waves humans can hear but with a larger frequency.

Uses of ultrasound

Ultrasound have have different uses.

Examples

• Cleaning: When you place an item in an ultrasonic bath, the vibrations caused by the ultrasound wave result in any attached dirt being shaken off. 
• Physiotherapy: Ultrasound can bring relief from joints and muscles as energy from the wave can be transferred to the soft tissue in the body.

Microphones

Microphones convert sound waves to electrical signals. A source (e.g a singer) will create sound waves when it produces sound. Information about the sound is stored in the energy of each sound wave. The wave's energy is then transferred by electrical work generating an electrical signal. This signal contains the information of the original sound wave.