Feasibility study on noise attenuation and stability of active noise cancelling headphones for mobile hearing...

This study evaluatesthe feasibility of active noise cancellation (ANC) headphones as transducers for mobile pure-tone audiometry (PTA) by assessing background noise attenuation and stimulus output stability under international standards. An experimental study was conducted using two commercially available ANC headphone models. Three experiments were conducted. Experiment I measured the background ambient noise attenuation compared with the International Standard Organization (ISO) 8253-1 standards; Experiment II evaluated ANC performance under background white and pure-tone noise across 10 audiometric frequencies (125 Hz-8000 Hz); Experiment III assessed the stability of the pure-tone output under steady (fixed at 70 dB) and dynamic (gradually increasing to 70 dB) background noise conditions using a head-and-torso simulator and calibrated measurement systems. With ANC activated, both headphone models effectively reduced ambient noise to within ISO-permissible levels, especially at frequencies <1000 Hz. The ANC function reduced the background white and pure-tone noise by up to 20 dB, with a greater reduction at low frequencies. The pure-tone output under steady white noise conditions remained stable (<1 dB SPL deviation), whereas fluctuations were observed under steady pure-tone noise, particularly at approximately 1500 Hz (up to 12 dB). Dynamic background white noise conditions showed a stable output (<5 dB fluctuation), whereas dynamic pure-tone noise conditions caused instability owing to the feedback interactions. Commercial ANC headphones demonstrated technical feasibility for mobile PTA, met the international ambient noise criteria particularly at low frequencies (<1000 Hz), and maintained a stable stimulus output under most tested conditions. Further validation in real-world complex noise environments is needed before self-administered hearing screening can be used clinically.