Question

The intensity of sound increases at night due to

Answer 1

At night temperature is low and air molecules are more closer than at day time which increases efficiency of sound transmission.hence intensity of sound increases. Also at night it will be more silent and we will feel more sound intensity.

Intensity doesn't increase. Rather noise decrease. So lesser the noise, more the sound which reaches to us.

Answer 2

The answer is increase in density of air.

The intensity of sound increases at night due to increase in density of air. At night, the temperature is more often than not lesser than what it was during the day time. As a result, the molecules in the air are more tightly and closely spaced during the night. This, in turn, increases the intensity of the sound. Moreover, it is often silent at night, which makes us feel that the sound has more intensity.