frequency. Sound is produced due to rapid to and fro motion from an object.

These motions are known as oscillations or vibrations emanating from the object.

The number of oscillations that are produced in a second is known as the frequency of an oscillating body.

We measure the frequency of an object in Hertz (Hz).

Hence, higher the frequency of sound, the more shrill will be that sound.

Hence, shrillness of sound is directly related to its frequency.