Question

We have learnt that vibration is necessary for producing sound. Explain why the sound produced by every vibrating body cannot be heard by us.

Answer 1

Sounds of frequencies less than about 20 vibrations per second (20 Hz) cannot be detected by the human ear. Such sounds are called inaudible.

On the higher side, sounds of frequencies higher than about 20,000 vibrations per second (20 kHz) are also not audible to the human ear.

Thus, for human ear, the range of audible frequencies is roughly from 20 Hz to 20,000 Hz.