An audiogram was classified as “fit” by a given preset if the audiogram's National Acoustic Laboratories–Non-Linear 2 (NAL-NL2) real-ear aided response (REAR) target was within ±5 dB of the preset's REAR target for all octave frequencies from 250 to 4000 Hz. The bold lines show examples of the three primary audiogram types not able to be fit: a) steeply sloping; b) rising; c) notched.