Equivalent hearing threshold levels for the RadioEar IP30 insert earphone and short-term stimuli: comparison of...

Objective: To determine equivalent threshold sound pressure levels (ETSPL) for the RadioEar IP30 insert earphone for standardised short-term stimuli: IEC 60645-3 reference clicks and tonebursts in the frequency range from 250 Hz to 6 kHz, using the standardised peak-equivalent ETSPL procedure (peETSPL) and a new proposal based on the unweighted equivalent continuous sound pressure level L_Zeq. of the periodically repeated short-term stimuli (L_ZeqETSPL).Design: Determination of peETSPL and L_ZeqETSPL hearing threshold levels with otologically normal test subjects under the conditions given in ISO 389-9 using the standardised occluded-ear simulator according to IEC 60318-4.Study sample: The study was based on tests with 25 subjects.Results: The peETSPLs for the RadioEar IP30 insert earphone were compared with the respective reference threshold levels of the insert earphone ER-3A as standardised in the ISO 389 standards series. The L_ZeqETSPL approach was tested by estimating the L_ZeqETSPLs from the peRETSPLs and comparing the estimate with the direct results.Conclusions: Equivalent hearing threshold levels for standardised short-term stimuli for the RadioEar IP30 insert earphone were determined according to ISO 389-9 and given as both peETPSL and L_ZeqETSPL. The RMS-based L_ZeqETSPL approach turned out to be well applicable for the RadioEar IP30 insert earphone.