Sound – Properties of Sound Wave – Part 2


Relationship between Time Period and Frequency

We know that time period is defined as the time taken by a wave to complete one oscillation and the frequency of a wave is defined as the number of oscillations per unit of time. Thus, there exists an inverse relation between the two. That is, frequency is nothing but the reciprocal of the time period and vice versa.

𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 = 1/𝑇𝑖𝑚𝑒 𝑃𝑒𝑟𝑖𝑜𝑑

ν  = 1/𝑇

Relationship between Pitch and Frequency

We know that pitch is the perceptual property of sound. It is determined by the frequency of the source. More the frequency higher will be the pitch.

The following two graphs represent two different sound waves.

Relationship: Pitch and Frequency

We can clearly see that the frequency of the second sound wave is much higher. More oscillations are happening per second relative to the first one. Hence the pitch of the second sound wave will be higher than the first one.

Relationship between Amplitude and Loudness

We know that a sound wave consists of regions of compression and rarefactions. The distance from the mean position to the maximum compression or rarefaction is called the amplitude of a sound wave.

The amplitude of a source defines the loudness of sound. More the amplitude of sound, more will be its loudness. The following two graphs represent two different sound waves.

Relationship: Amplitude and Loudness

 

The particles of the sound wave in the second case vibrate with a larger amplitude when compared to the first case. Thus, the loudness will be higher in the second case.