Question

define audible sound and inaudible sound?

Answer 1

Audible sound: The human ear can only recognize sounds of frequencies in the range of 20 Hz and 20,000 Hz and this range of frequency is called audible sound. This audible range varies from person to person and also with age.
Inaudible sound: Sound with frequency below 20 hertz and above 20,000 hertz is called sound of inaudible range. Humans cannot hear the sound of inaudible range.Sounds of frequencies less than 20 Hz are called infrasonic sounds, while sounds of frequencies greater than 20,000 Hz are called subsonic or ultrasonic sounds.

Answer 2

. Vibrations transmitted through an elastic solid or a liquid or gas, with frequencies in the approximate range of 20 to 20,000 hertz, capable of being detected by human organs of hearing.

Human ear cannot detect sound frequencies less than 20 vibrations per second i.e. 20 Hz. So any sound below this frequency will be inaudible sound