Question

with the increase in dash of a vibrating body, the loudness of sound increases​

Answer 1

Answer:

Amplitude

Hope it helps :)

Answer 2

Answer:

Loudness of a sound $l = 10 \: log_{10} \: \frac{I}{Io}$

where intensity I is proportional to the square of the amplitude A of vibrating body i.e. $1 \infty {A}^{2}$

Hence loudness of sound depends directly on the amplitude of vibrating body.

Thus, loudness of sound increases with increase in amplitude of vibrating body.