Question

In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid. ... Humans can only hear sound waves as distinct pitches when the frequency lies between about 20 Hz and 20 kHz

Answer 1

Answer:

Human ear perceives frequencies between 20 Hz (lowest pitch) to 20 kHz (highest pitch). All sounds below 20 Hz are qualified as infrasounds, althought some animals (ex. mole-rat, or elephant) are hearing them.