Which aspect of sound does intensity refer to?

Intensity refers to the power carried by sound waves and is directly related to the perception of loudness. It is measured in decibels (dB) and represents how much energy a sound wave carries per unit area. In practical terms, a sound with greater intensity is perceived as being louder to the human ear.

The perception of loudness varies with intensity: as the intensity of a sound increases, so does our perception of it being loud. This correlation establishes why intensity is primarily associated with loudness rather than with other characteristics of sound like frequency, pitch, or duration.

Frequency relates to how many times a sound wave oscillates per second and is perceived as pitch, while duration pertains to the length of time a sound lasts. These attributes are important in their own right but do not define intensity or its relationship to our auditory experience. Thus, understanding intensity as it relates to loudness is fundamental in fields such as audiology and hearing instrument fitting.