Reference hearing threshold levels for short duration signals

Hearing thresholds for clicks and tonebursts were measured on 26 otologically normal persons (age 18–25 years) using the earphones Sennheiser HDA 200 and Telephonics TDH 39. The test signals are specified in IEC 60645-3 and in ISO 389-9. The acoustic test signals were presented both as a single stimulus and as repeated stimuli with the repetition rate of 20 Hz. The frequencies used for the toneburst were: 250, 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz. Test signals and measurement methods were all in accordance with the recommendations given in ISO 389-9: Preferred test conditions for the determination of reference hearing threshold levels. The results are given as peak-to-peak equivalent threshold sound pressure levels (peETSPL). The results are in good agreement with other sparse results from literature and are part of the basis for the ISO 389-6 standard from 2007.