Reliability Evaluation of a Portable Active Noise Control-Integrated Audiometer for Clinical Hearing Assessment

Hearing loss is a major global health challenge, and pure-tone audiometry remains the gold standard for assessing auditory thresholds. However, conventional clinical audiometry requires specialized sound-proof booths, which limit its accessibility in resource-constrained settings. To address this limitation, we developed and evaluated a portable audiometry system, designated as the E200, incorporating active noise control (ANC) technology with integrated supra-aural earphones.

In this 2-phase study, reference equivalent threshold sound pressure level calibration was first performed on 183 volunteers comparing E200 to conventional clinical pure-tone audiometric testing. Subsequently, we prospectively enrolled 114 participants with diverse otologic pathologies from tertiary otology clinics to evaluate the validity of the E200 audiometric system.

Data from 228 ears were collected from 114 participants, with 7 frequencies tested/ear, resulting in 1596 sets of data. The two one-sided test equivalence analysis demonstrated that all tested frequencies met the equivalence criterion at the ±5 dB margin. Pure-tone average (PTA) was derived from the arithmetic mean of air-conduction thresholds at standard speech frequencies (0.5, 1, 2, and 4 kHz), with hearing loss severity classified according to WHO (2021) criteria: normal (<20 dB hearing level [HL]), mild-to-moderate (20-<50 dB HL), and moderate-to-severe (≥50 dB HL). Both Bland-Altman plots and Cohen's κ statistics demonstrated good agreement with the PTA results.

This ANC-integrated portable audiometer demonstrates promising potential for hearing screening outside conventional sound-proof booths; however, its long-term clinical value and practical applications require further investigation and validation.