Feasibility of Personal Sound Amplification Products in Patients With Moderate Hearing Loss: A Pilot Study

Objectives. This study was conducted to investigate the electroacoustic characteristics of personal sound amplification products (PSAPs), to identify whether PSAPs provide adequate gain and output for three common hearing loss (HL) configurations, and to compare the benefits of a representative PSAP (RPSAP) and a conventional hearing aid (HA) for clinical hearing outcomes as a pilot study. Methods. The study comprised three phases: electroacoustic analysis, simulated real-ear measurements (REMs), and clinical hearing experiments. Electroacoustic analysis and simulated REMs were performed for three basic PSAPs (Beetho-SOL, EarJJang, and Geniesori2) and three high-end PSAPs (Hearing Able, Olive Smart Ear, and SoriIn) using the Aurical Hearing Instrument Test box with a 2-mL coupler. Four electroacoustic characteristics (maximum output sound pressure level at 90 dB SPL, frequency range, equivalent input noise, and total harmonic distortion) were investigated. By simulated REMs, appropriate levels of the six PSAPs for three common HL configurations (mild-to-moderate high-frequency HL, moderate to moderately severe sloping HL, and moderate flat HL) were determined. Clinical experiments compared the performance of RPSAP to HA, both of which were fitted by audiologists using REMs. Clinical experiments were administered using functional gain, a word recognition test, and the Korean version of the Hearing in Noise Test in six participants with bilateral moderate sensorineural HL. Results. The two high-end devices met all tolerances. One basic and two high-end PSAPs showed appropriate levels for three common HL configurations. In the clinical experiments, the RPSAP showed better performance than unaided, but slightly worse than HA under all test conditions. Conclusion. Certain PSAPs met all specified tolerances for electroacoustic analysis and approximated prescriptive targets in well-controlled laboratory conditions. The pilot clinical experiments explored the possibility that the RPSAP could serve as a hearing assistive device for patients with moderate HL.