Figure 1.

Idealized loudness-growth functions (categorical loudness judgment versus presentation level) for a typical (control) listener with normal-hearing sensitivity (solid line) and for a pair of hearing-impaired listeners (with similar hearing thresholds) representative of primary hyperacusis (square symbols) and classical loudness recruitment (triangle symbols). The reduced dynamic ranges (i.e., the difference between the level judged as “uncomfortably loud” and the hearing threshold, assumed here to correspond closely to the level judged as “very soft”) are indicated for each hearing-impaired listener by the associated bar shown at the top of the panel. The corresponding control dynamic range also is depicted. Abbreviation: HL, decibels in hearing level.