One-eartip solution for pure-tone audiometry and acoustic immittance measurements: using insert earphone with an immittance probe ear tip

Abstract

Objective

Two consecutive studies sought to determine the (1) Equivalent Threshold Sound Pressure Levels (ETSPLs) and, (2) real ear attenuation thresholds (REAT) for the KUDUwave earcup configured with an insert earphone using a typical immittance probe tip (TPT).

Design

(1) Hearing thresholds were measured for frequencies 125 to 8000 Hz using the TPT. ETSPLs were calculated in an IEC 60318-4 occluded ear simulator. (2) REAT were obtained by measuring sound field thresholds with ears uncovered and covered with the investigational transducer. The attenuation values were used to determine the maximum permissible ambient noise levels (MPANLs).

Study sample

(1) Study 1 included twenty-five adult participants with no otologic diseases (8 females; 18 − 33 years). (2) Study 2 included fifteen normal hearing participants aged 21–31 years.

Results

Established ETSPLs, REAT, and MPANLs for the TPT are presented in this paper. The determined TPT ETSPLs differed from the ER-3A foam tip insert earphone’s RETSPLs reported in ISO 389-2.

Conclusions

The investigational transducer can be used for pure-tone audiometry provided the reported MPANLs are adhered to, and ETSPL values are employed for calibration purposes. The advantage is to achieve a cost-effective one-probe tip solution for pure tone audiometry and immittance measurement.