Comment on the statement 'loudness of sound is of subjective nature, while intensity is of objective nature'.

The loudness of a sound depends on (i) the intensity i.e the energy conveyed by the sound wave near the eardrum of the listener and (ii) the sensitivity of the ears of the listener. Thus, the loudness of sound of a given intensity may differ from listener to listener i.e., the sound of the same intensity may appear to to be of different loudness to different persons.

Further, two sounds of the same intensity, but of different frequencies may differ in loudness even to the same listener because the sensitivity of ears of a person is different for different frequencies.

For normal ears, the sensitivity is maximum at the frequency 1 kHz.

The intensity of the sound wave at a point of the medium is the amount of sound energy passing per second normally through a unit area at that point.

Greater the energy carried by a sound wave, greater is the intensity of sound.

The unit of intensity of the sound wave is watt per metre² (W m^-2).

Thus, for a sound wave loudness has a subjective nature i.e., it depends on the listener, while intensity, being a measurable quantity, has an objective nature.