ABSTRACT
Loudness is a listener’s sensation of the strength of a sound. Loudness forms a continuum from, at one end, sounds that are so quiet they are only just detectable by a listener to, at the other end, sounds that are so loud as to be painful. As one would expect, the sensation of loudness is associated with the sound pressure amplitude of a sound. An increase in sound pressure amplitude will result in an increase in loudness, other things being equal. However, it is important to remember that the sensitivity of hearing differs according to frequency. So a sound of 50 dB SPL will not necessarily be louder than a sound of 40 dB SPL, if the frequency composition of the two sounds is different.
