Figure 1 Loudness models for normal subjects, patients with loudness recruitment, and patients with hyperacusis (Cox, 1997). The maximum discomfort threshold for a normal person is 100 dB HL. Patients with loudness recruitment have a largely unchanged maximum discomfort threshold, although they often have sensorineural deafness, while some patients with hyperacusis have an increased hearing threshold, the maximum discomfort threshold falls to 70–80 dB instead, thus the range of hearing tolerance is significantly reduced.