Question

how does the wavelength depend upon the loudness of sound​

Answer 1

Answer: It is independent

Explanation: A loudness of any source or sound is measured in decibels. In the graphical representation, the sound is sketched in a wave form. The different components of a wave define various other factors. Like frequency, time period, amplitude etc.

The component of Amplitude is the one which shows how loud is the sound. This component is completely independent. Hence, this has nothing to do with the wavelength.