Equivalent threshold sound pressure levels for Sennheiser HDA 200 earphone and Etymotic Research ER-2 insert earphone in the frequency range 125 Hz to 16 kHz.

Equivalent Threshold Sound Pressure Levels (ETSPLs) have been determined for the Sennheiser HDA 200 earphone and the Etymotic Research ER-2 insert earphone. Thirty-one young normal-hearing test subjects participated and the thresholds were determined for all recommended frequencies in the frequency range 125 Hz to 16 kHz. The results for the HDA 200 earphone are generally in very good agreement with the results from two other investigations which are available at present. Only at 6 kHz is a 9 dB deviation found and at 8 kHz a 6 dB deviation is found between the three investigations. For ER-2 it has not been possible to find other ETSPL determinations in the literature.