The loudness of a sound depends upon the

The loudness of a sound is primarily determined by the amplitude of the sound waves. Amplitude represents the maximum displacement of particles from their equilibrium position as a wave passes through a medium. Physically, a higher amplitude corresponds to greater energy and intensity carried by the wave. While loudness is a subjective perception of the human ear, it is directly related to the physical strength or amplitude of the wave; larger amplitudes produce louder sound sensations because they exert more pressure variation on the ear [1]. In contrast, the frequency of a sound wave determines its pitch (shrillness or depth), and the velocity depends on the properties of the medium, such as density and elasticity. Therefore, while other factors like frequency can influence perception, loudness is fundamentally dependent on amplitude.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 4: Earths Interior > Primary Waves (P-Waves) > p. 60