Hearing aids are the primary tool in non-medical rehabilitation for individuals with hearing loss. However, only about 25% of those with hearing loss in high-income countries own hearing aids. This hearing aid uptake number could be as low as 1-5% in low- and middle-income countries. While the audiology community and those they serve have attended to issues related to the effects of untreated hearing loss and poor hearing aid uptake, health care has undergone a consumer-driven revolution. Popularity is growing for a Direct-to-Consumer approach to health care service delivery, which is believed to provide greater accessibility to services and affordability for patients. There is a growing number of Direct-to-Consumer (DTC) hearing devices (e.g., Personal Sound Amplification Products [PSAPs]; Over-the-Counter [OTC] Hearing Aids) in the market especially fueled by regulatory changes (e.g., Over-the-Counter Hearing Aid Act of 2017). These devices are bought by individuals (e.g., online, pharmacies, supermarkets) with hearing loss without consulting hearing healthcare professionals. This project aims to develop and evaluate DCT hearing devices and service delivery models.

This project touches on the research theme 1 (online user activities, theme 3 (Internet- and mHealth-based interventions), theme 4 (new service delivery models), and theme 5 (synthesis of evidence). Following are the specific studies within this larger project.

Although there is limited understanding of efficacy of these devices for people with hearing loss, more and more consumers are purchasing DTC hearing devices online and providing their views in online reviews. We extracted a large number of Amazon verified consumer reviews (n=11,258) and examined them using qualitative (i.e., content analysis) and quantitative (i.e., cluster analysis of the textual data) to examine the consumer perspectives of the benefits and limitations of the DTC hearing devices (Manchaiah et al., 2019 JSLHR). We believe that examining the online reviews can provide some preliminary understanding of potential benefits and limitations of these devices, although clinical studies need to confirm these results. However, such studies could certainly inform further refinement of the device as well as identify key issues that needs to be addressed in making these devices more user friendly.

Study Lead: Vinaya Manchaiah

There is growing evidence on applications of DTC hearing devices for people with hearing loss. In a series of literature reviews, we examined the applications of DCT hearing devices for adults with hearing loss including studies on electroacoustic characteristics, consumer surveys, and outcome studies (Manchaiah et al., 2017 Clinical Interventions in Aging; Manchaiah, 2018 ASHA Perspectives). In addition, in a systematic review, we have also examined the efficacy of DTC hearing devices based on clinical studies examining the outcomes (Tran & Manchaiah, 2018 Journal of Audiology & Otology).

Study Lead: Vinaya Manchaiah

While the costs of the electronic components have reduced substantially, the cost of a hearing aid has risen steadily to the point that it has become unaffordable for the majority of the

population with Age-Related Hearing Loss (ARHL) especially for those residing in low- and middle-income countries. We have developed an ultra-low-cost, affordable and accessible hearing aid device (‘LoCHAid’), specifically targeted towards treating ARHL in elderly patients (Sinha et al., 2020 Plos One). The LoCHAid components cost 98 cents (< $1) when purchased in bulk for 10,000 units and can be personalized for each user through a 3D-printable case. It is designed to be an Over-the-Counter (OTC) self-serviceable solution for elderly individuals with ARHL. Electroacoustic measurements show that the device meets most of the targets set out by the WHO Preferred Product Profile and Consumer Technology Association for hearing aids. The frequency response of the hearing aid shows selectable gain in the range of 4-8 kHz, and mild to moderate gain between 200-1000 Hz, and shows very limited total distortion (1%). Simulated gain measurements show that the LoCHAid is well fitted to a range of ARHL profiles for males and females between the ages of 60-79 years. Overall, the measurements show that the device offers the potential to benefit individuals with ARHL. Thus, our proposed design has the potential to address the challenge of affordable and accessible hearing technology for hearing impaired elderly individuals especially in low- and middle-income countries. Clinical trials are underway to examine its efficasy both in lab setting as well as in field conditions.

Study Lead: Saad Bhamla

Smartphones have revolutionized day to day life. As the smartphones are becoming more affordable, more and more people across the globe including in people with low- and middle-incomes countries are using them. Smartphones are used as a single device that can serve multiple purpose. There are several smartphone applications that serve as sound amplification apps that could potentially benefit individuals with hearing loss. Such solutions can also improve access to hearing devices at considerably lower costs. Considering these developments, we are working on developing an Android-based smartphone app that could provide serve as amplification device for individuals with mild-to-moderate hearing loss. Early stages of this work have identified some major barriers (e.g., latency or time delay of amplified signals), although these limitations could be resolved in future generation Android smartphones. We continue to explore how smartphones can be used as an amplification device with am app supporting the sound processing.

Study Lead: Saad Bhamla