Question

The sounds having frequency less than $20Hz$ are called ultrasonics. True or False?

Answer 1

$False$

The sounds having frequency less than 20Hz20Hz are called infrasonics.

The sounds having frequency greater than 20kHz20Hz are called ultrasonics.

Human beings can hear only those sounds which are in the frequency range of 20Hz to 20kHz.

Thus the infrasonic and ultrasonic sounds are not audible to humans.