Question

Differentiate between audible and inaudible sounds.

Answer 1

Hint : An audible sound is considered something perceptible to the ear. An inaudible sound is considered to be a sound that is imperceptible or unclear to the ear.

Complete step by step answer
In general, when sounds are emitted or created, they propagate with a certain frequency through a medium by setting the molecules of the medium into vibration. To a certain extent, frequency is proportional to loudness or intensity. Hence, since there’s no lower limit to the frequency at which a sound can propagate, there are some sounds that are actually generated around us which cannot be heard or perceived by the human ear. These sounds are too low to be picked up by our ear. These low frequency sounds are called infrasound.
Besides the sound that is too low in frequency (hence loudness) to be perceived by the human, there are also other sounds that are too high in frequency to be heard. These sounds are called ultrasound.
Generally, any sound that cannot be heard / perceived by the human ear is considered inaudible, and are called inaudible sounds.
Similarly the sounds frequencies within our range of hearing are called audible sounds. The range of frequency perceptible by the human ear is from 20 Hz to 20 kHz. Any sound frequency, higher than 20 kHz (ultrasound) and lower than 20 Hz (infrasound) is considered inaudible.

Note
We should note the emphasis on the reference to the human ear. For clarity, audible and inaudible sounds are defined with respect to the human ear, just like how visible light is the light in the range of perceptibility to the human eye. Many other animals can hear either above or below or both our range of hearing.