Mel

A unit of pitch proposed by Stevens, Volkmann and Newmann in 1937. The mel scale is a scale of pitches judged by listeners to be equal in distance one from another. The reference point between this scale and normal frequency measurement is defined by equating a 1000 Hz tone, 40 dB above the listener's threshold, with a pitch of 1000 mels. Below about 500 Hz the mel and hertz scales coincide; above that, larger and larger intervals are judged by listeners to produce equal pitch increments.

As a result, four octaves on the hertz scale above 500 Hz are judged to comprise about two octaves on the mel scale. Many musicians and psychologists prefer a two-dimensional representation of pitch by chroma or tone colour and tone-height.

Compare: Critical Band, Sone.

The mel scale as a function of frequency (from Appleton and Perera, eds., The Development and Practice of Electronic Music, Prentice-Hall, 1975, p. 56; after Stevens and Davis, Hearing; used by permission).