Which of the following are the characteristics of sound?
Pitch
Loudness
Pitch - It is a perceptual property of sound and it depends on the frequency. The higher the frequency higher will be the pitch and vice-versa.
Loudness - Loudness depends on the amplitude of the sound. It is directly proportional to the amplitude of the sound.
Density - Density is defined as mass by volume.
Surface tension - It is a property of a liquid
From the above pitch, loudness is characteristics of sound.