1 Department of Acoustic Technology, Technical University of Denmark2 Oticon A/S3 Department of Electrical Engineering, Technical University of Denmark
The binaural free field hearing threshold for pure tones (the minimum audible field, MAF) and Equivalent Threshold Sound Pressure Levels (ETSPL) for the Sennheiser HDA 200 earphone and the Etymotic Research ER-2 insert earphone have been determined for thirty-one otologically normal test subjects in the age range 18 to 25 years. The frequencies were in the range 125 Hz to 16 kHz. MAF results are in good agreement with ISO 226 at frequencies below 1 kHz and other recent determinations of the free field hearing threshold at high frequencies. The ETSPL results for the HDA 200 earphone are generally in very good agreement with the results from other investigations. For ER-2 it has not been possible to find other ETSPL determinations in the literature.