Differences and intersubject variability of loudness discomfort levels measured in sound pressure level and hearing level for TDH-50P and ER-3A earphones.

Loudness discomfort levels (LDLs) were measured in dB HL and SPL at discrete frequencies between 500 to 4000 Hz on 31 hearing-impaired ears using TDH-50P and ER-3A earphones. The results revealed no significant differences in the measured sound pressure level (SPL) between the two earphones at all test frequencies. However, with dB HL measurements, statistically significant differences were revealed at 1500 and 4000 Hz between earphone conditions. The results also revealed large intersubject differences in the measured LDL (HL and SPL) for both earphones. The results of this study highlight the difficulty in accurately predicting individual performance from averaged group data.