8/14/2019 Summery of Sound Properties

1/2

Sound Properties

A sound wave is a pressure disturbance which travels through a medium by

particle-to-particle interaction. As one particle becomes disturbed, it

transfer it on the next adjacent particle, thus disturbing that particle andtransporting the energy through the medium. the speed of a sound wave

refers to how fast the disturbance is passed from particle to particle. While

frequency refers to the number of vibrations which an individual particle

makes per unit of time

it is expressed in units of meters/second .

Speed = distance/time

The speed of any wave depends upon the properties of the medium through

which the wave is traveling. Typically there are two essential types of

properties which affect wave speed - inertial properties and elastic

properties. Elastic properties are those properties related to the tendency

of a material to maintain its shape and not deform whenever a force or

stress is applied to it. In general, solids have the strongest interactions

between particles, followed by liquids and then gases. For this reason, sound

waves travel faster in solids than they do in liquids & than in gases.

The density of a medium is an inertial property. The greater the inertia or

density of medium, and the slower that the wave will be. As stated above,

sound waves travel faster in solids than in liquids & in gases. However, the

inertial property tends to be the property which has a greatest impact upon

the speed of sound.

sound wave has a speed which is related to the frequency and the

wavelength of the wave.

Speed = Wavelength *Frequency

8/14/2019 Summery of Sound Properties

2/2

When a wave enters from one medium to another medium, a portion of the

wave undergoes reflection and a portion of the wave undergoes transmission

across the boundary. The amount of reflection depends upon the

dissimilarity of the two medium.

Reflection of sound waves from of surfaces can lead to two phenomenon -

echo & reverberation.

Diffraction is a change in direction of waves as it passes from a barrier in

the path. The amount of diffraction increases with increasing wavelength

and decreases with decreasing wavelength.

Refraction of waves is a change in the direction of waves as they pass fromone medium to another medium. Refraction of the path of waves, is also

accompanied by a change in speed and wavelength.