Rahul is playing the drums. Then which of the following characteristics of sound would result in increase in loudness?

Answer is A.

The intensity or loudness of a sound depends upon the extent to which the sounding body vibrates, i.e., the amplitude of vibration. A sound is louder as the amplitude of vibration is greater, and the intensity decreases as the distance from the source increases. Loudness is measured in units and are called decibels.