Loudness of sound and Intensity of sound

The loudness of sound and the intensity of sound are related but distinct concepts.

1. Loudness of sound:

   • Loudness refers to the subjective perception of the intensity of sound by the human ear.
   • It is influenced by the amplitude or strength of the sound wave.
   • The unit used to measure loudness is the decibel (dB).
   • The human ear has a range of sensitivity to different frequencies, so the loudness of a sound can also depend on its frequency.

2. Intensity of sound:

   • Intensity refers to the objective measurement of the energy carried by a sound wave per unit area.
   • It is determined by the amplitude of the sound wave and the distance from the source of the sound.
   • The unit used to measure intensity is watts per square meter (W/m²).
   • Intensity can be calculated using the formula: Intensity = Power / Area, where power is the energy carried by the sound wave and area is the surface area over which the sound wave is spread.

In summary, loudness is a subjective perception of sound intensity, while intensity is an objective measurement of the energy carried by a sound wave.