loudness (n.)

The attribute of auditory sensation in terms of which a sound may be ordered on a scale from soft to loud. It is an AUDITORY PHONETIC feature, corresponding to some degree with the ACOUSTIC features of intensity or power (measured in decibels (dB)), which in the study of speech is based on the size of the vibrations of the VOCAL FOLDS, as a result of variations in air pressure. There is, however, no direct or parallel correlation between loudness (or ‘volume’) and intensity: other factors than intensity may affect our sensation of loudness; e.g. increasing the FREQUENCY of vocal-fold vibrations may make one sound seem louder than another. The linguistic use of loudness is of particular interest to the PHONOLOGIST, and this is studied under the heading of STRESS.