The Mel Scale

Stevens (and others) wanted to construct a scale that reflected how people hear musical tones:

• listeners were asked to adjust tones so that one tone was “half as high” as another, and other such subdivisions of the frequency range.

Resulted in the Mel Scale (for melody):

• a perceptual scale of pitches judged by listeners to be equal in distance from one another
• the reference of 1000 mels was assigned as having a frequency of 1000 Hz (40 dB above threshold).

A similar Bark Scale (Zwicker) ranges from 1 to 24 and corresponds to the first 24 critical bands.