Decibel (dB): One tenth of a bel; a quantative unit of sound intensity with a logarithmic relationship to the amplitude of the sound; in audiology, sound intensity is measured in terms of the ratio between the intensity of the sound being measured and a standard reference intensity.

Slight to Mild                 21 - 40 dB               26 - 40 dB

Mild to Moderate                           41 - 55 dB

Moderate                                        56 - 70 dB

Severe                                             71 - 90 dB

Profound                                          91 plus dB