Question

why is sound heard clearly at night than during the day ? (please explain easily)

Answer 1

it is because it is quiter at night than in the daytime. therefore it is easy to hear sound far away at night.

Answer 2

Light does not really affect sound. Sound is made of vibrations (aka rapid pressure fluctuations) in air, water, or solid material. Light is made of vibrations in the electric and magnetic fields. Now, the timescale (for example, the oscillation speed or the wave speed) for light is much faster than that for sound, so sound doesn't even notice when light is around.