Interpretation of audiometry and tympanometry

What it is

Audiometry is both qualitative and quantitative: it gives the type of hearing loss and its severity. The patterns are CHL, SNHL or mixed. For assessment, 3 frequencies are taken as reference points: 500 Hz, 1000 Hz and 2000 Hz. The severity bands run normal, slight, mild, moderate, moderately-severe, severe and profound, and each band is set against a hearing level axis in dB HL that runs from 0 at the top of the chart down to 120. Mild ends at 40 dB, moderately-severe ends at 70 dB, and below 90 dB the loss is profound.