Authors; Ibrahim Almufarrij, Kevin J. Munro, Piers Dawes, Michael A. Stone, and Harvey Dillon

Abstract; Direct-to-consumer (DTC) hearing devices can be purchased without consulting a hearing health professional.

This project aims to compare 28 DTC devices with the most popular hearing aid supplied by the U.K. National Health Service (NHS). The comparison was based on technical performance, cosmetic acceptability, and the ability to match commonly used gain and slope targets. Electroacoustic performance was evaluated in a 2-cc coupler. Match to prescription target for both gain and slope was measured on a Knowles Electronic Manikin for Acoustic Research using a mild and also a moderate sloping hearing loss. Using an online blinded paired comparison of each DTC and the NHS reference device, 126 participants (50 were hearing aid users and 76 were nonhearing aid users) assessed the cosmetic appearance and rated their willingness-to-wear the DTC devices.

The results revealed that higher purchase prices were generally associated with a better match to prescribed gain–frequency response shapes, lower distortion, wider bandwidth, better cosmetic acceptability, and higher willingness-to-wear. On every parameter measured, there were devices that performed worse than the NHS device. Most of the devices were rated lower in terms of aesthetic design than the NHS device and provided gain– frequency responses and maximum output levels that were markedly different from those prescribed for commonly encountered audiograms. Because of the absence or inflexibility of most of the devices, they have the potential to deliver poor sound quality and uncomfortably loud sounds. The challenge for manufacturers is to develop low-cost products with cosmetic appeal and appropriate electroacoustic characteristics.

Keywords hearing aids, personal sound amplification products, gain, slope, direct-to-consumer

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