Normal threshold of hearing at preferred frequencies.

Hearing thresholds have been determined on 10 young normal-hearing subjects at the preferred frequencies for acoustical measurements in steps of 1/3 octave from 500 to 8000 Hz. The study has been done in conjunction with the task given to ISO/TC43/WG1 to produce an international standard on normal thresholds of hearing at these frequencies. The results are given as equivalent threshold sound pressure levels measured on acoustic coupler according to IEC 303 and on artificial ear according to IEC 318.