<P> The "loudness" control on some consumer stereos alters the frequency response curve to correspond roughly with the equal loudness characteristic of the ear . Loudness compensation is intended to make the recorded music sound more natural when played at a lower levels by boosting low frequencies, to which the ear is less sensitive at lower sound pressure levels . </P> <P> Loudness normalization is a specific type of audio normalization that equalizes perceived level such that, for instance, commercials do not sound louder than television programs . Loudness normalization schemes exist for a number of audio applications . </P> <Ul> <Li> Commercial Advertisement Loudness Mitigation Act </Li> <Li> European Broadcasting Union R128 </Li> </Ul> <Li> Commercial Advertisement Loudness Mitigation Act </Li>

At low frequencies our perception of loudness is determined by