of any hearing threshold. PGSR is rarely used : if he does not hear it, whenever some advantage or remuneration is at stake, such as obtain- 7. TESTING FOR AUDITORY TONE DECAY of damage in the inner ear, abnormal tone of pressure on or damage to the audi-

doi:10.1201/b21609-21

Chapter

of any hearing threshold. PGSR is rarely used

ABSTRACT

This method of establishing pure-tone thresholds permits the patient to trace his/her own audiogram as the tone or tones are presented automatically. Each ear is tested separately. The patient holds a hand switch and has on a set of earphones through which he hears the tone. As soon as he/she hears the tone he/she presses the switch, which causes the sound to decrease in loudness, and holds it down until the tone is gone. This procedure continues until the full range of frequencies has been tested.