Loudness
The Japanese Rockband Loudness (heavy metal)
Loudness is a sound which is described as loud if it is high in volume (amplitude, or sound pressure). Loudness is the perception of a sound wave's amplitude. A "loudness" control on a stereo alters a frequency response curve or uses audio level compression to make a selection sound louder.
See also decibel, sone, Phon (not Phone).
By extension, a person who emits noise (with the voice or otherwise) either loudly or a lot of the time can be described as loud. Whether this is an insult or a compliment is a matter of personal preference: some people self-describe as "loud" while many others consider loud people to be intensely irritating.
Clothing that is distasteful and bright-colored may also be referred to as loud; this is an example of poetic synaesthesia.
