Evidence of Emerging Technologies as a Treatment Option for Mild-to-Moderate Hearing Loss

by David Maidment, PhD

Dr. David Maidment, PhD

In August 2017, President Trump signed into law the Food and Drug Administration (FDA) Reauthorization Act, which included the Over-the-Counter (OTC) Hearing Aid Act. The primary intention of the Act is to improve accessibility and affordability to hearing healthcare in adults with mild to moderate hearing loss.

The FDA has one more year (by August 2020) to specify how they will regulate this new category of OTC hearing aids that will not require hearing healthcare professional. 

For some, OTC hearing aids are a much-needed opportunity that may help to address the health burden associated with untreated hearing loss. For others, particularly clinicians, there is concern that OTC hearing aids present potential uncertainty and disruption. Whichever side of the fence you’re on, I will not try to convince you of one argument over the other. Rather, I want to advocate the need for high-quality evidence, which I believe is needed as a priority so that informed decisions can be made by everyone affected by these legislative changes. As such, in this blog I will share with you the evidence that my colleagues and I have generated in the past 3-4 years in the area of new and emerging technologies for hearing loss. 

Overall, we have found that there is limited high-quality evidence assessing new and emerging technologies for hearing loss. Our research has also shown that adults living with hearing loss want the ability to adjust and personalize their hearing devices in any listening situation to improve their ability to communicate with others. This functionality empowers users, providing them with a greater sense of control, reducing stigma, less frustration and greater social participation. 

The Problem: Hearing Aids and Untreated Hearing Loss

Hearing loss is highly prevalent, but it can take an individual up to a decade to seek help once their hearing difficulties emerge. This delay can result in persistent psychosocial difficulties for the individual and their frequent communication partners, leading to social withdrawal and isolation, as well as anxiety and depression.

Failing to treat hearing loss in older adults is also associated with an increased risk of falls, as well as developing dementia. In the UK it has been estimated that hearing loss costs the economy approximately £30.1 ($37.9 USD) billion per year due to higher unemployment rates, increased social care demands and lower quality of life. In the US, hearing loss has even been estimated to cost the economy upwards of $150 billion. Thus, it is vital that effective intervention strategies are available to alleviate these costs to the individual, as well as society at large. 

Hearing aids are currently the primary clinical intervention for hearing loss and have been shown to be effective in adults with mild to moderate hearing loss¹. Nevertheless, despite advances in technology, hearing aid adoption rates remain low; the majority (2 out of 3) of adults who would benefit from hearing aids fail to access them. Although hearing aid adoption is better in countries where their provision is subsidized or completely free-of-charge, penetration is still only around 40-50%, a figure that has remained relatively stable for some time. 

Hearing aid non-use is by no means a new problem and has been the focus of research for many years. In addition to high costs associated with hearing healthcare to the individual, additional reasons for low uptake include poor acceptance of hearing aids, low self-reported activity limitations and participation restrictions, reduced hearing aid self-efficacy and a lack of social support to manage hearing loss.

The stigma associated with hearing loss and hearing aids further prevents people seeking help. In addition, there may be accessibility barriers, such as clinic-based service delivery models that fail to meet the needs and/or preferences of all adults living with hearing loss, such as those with reduced mobility or those who live some distance from their nearest clinic.

On this basis, it is perhaps no surprise that in 2016 the National Academies of Science, Engineering and Medicine released their report outlining several recommendations to improve accessibility to and affordability of hearing healthcare². One of these recommendations included the introduction of a new device category for OTC hearing aids, which potentially fueled the changes to US legislation seen in 2017. 

A Potential solution: New and Emerging Devices

In the last decade there has been an explosion of new and emerging technologies for hearing loss. It is important that I first clarify what I mean by new and emerging technologies given that different terms are often used interchangeably or synonymously.

In this blog, when I refer to new and emerging devices, I am including standalone devices that provide amplification but are not regulated medical devices, such as personal sound amplification products (PSAPs), hearables or smartphone hearing aid applications (or apps).

Furthermore, I also use the term of new and emerging devices more broadly to encompass products that link wirelessly to hearing aids, such as made-for-smartphone hearing aids. 

Unlike conventional hearing aids that must be programmed and adjusted by a hearing healthcare professional, new and emerging technologies can allow the user to fit and/or fine-tune their sound settings (e.g. gain and frequency response) in any listening situation away from the clinic.

You might be thinking that there is nothing new about what I have just described, given that hearing aids also allow users to discreetly adjust their sound settings via a volume/program switch or remote control.

What is novel to new and emerging technologies is that they can connect to smartphone technologies. Smartphones are ubiquitous and, in the context of hearing loss, allow the user to adjust and personalize their hearing programs via an accompanying app. Linkage to smartphone devices can not only provide greater user-controllability, but can also offer additional functionality, such as health tracking and remote assistance. 

Interestingly, the use of smartphone technologies in older adults is increasing year-on-year. In the UK, for example, smartphone ownership has risen in 55+ year old age group from 19% (2012) to 71% (2017). A similar pattern of findings has also been shown in the USA, with smartphone ownership in 50 to 64-year old age group rising from 34% (2012) to 73% (2018). This means that the typical hearing aid user is already using smartphone technologies and, as a result, would be a prime candidate for a new and emerging device to address their hearing loss. 

What’s the Evidence that New and Emerging Devices are Effective?

New and emerging devices may be advantageous because they enable new service delivery models that may be more affordable and/or accessible to adults living with hearing loss.

PSAPs and smartphone hearing aid apps, for instance, may be able to address barriers associated with accessibility and affordability because they are relatively cheaper than hearing aids and can be purchased directly by the user. However, what evidence is available to show that these devices are an appropriate management option for adults living with hearing loss?

There is growing pressure from consumers, health care insurers and policy makers to demonstrate that new intervention procedures are equally as effective as the “gold standard” (i.e. hearing aids provided by a hearing healthcare professional). Without such evidence, we run the risk of replacing one problem with another.

There are several recent research studies showing that, in comparison to conventional hearing aids, PSAPs and smartphone apps provide comparable electroacoustic characteristics and speech-in-noise performance^3-5.

In view of this ever-increasing evidence-base, Dr. Mel Ferguson and I opted to complete the first systematic review and meta-analysis investigating alternative listening devices. Unlike a literature review, systematic reviews with meta-analyses (i.e. where data is pooled across multiple similar studies) provide the highest quality evidence. This is because systematic reviews rigorously address a specific research question using explicit methods.

In our review, we assessed the effectiveness of alternative listening devices in comparison to conventional hearing aids in adults with mild and moderate hearing loss. In accordance with best practices, the review protocol was registered online and published in  a peer-reviewed, open-access publication⁶, maximizing transparency of the review process. 

We made the pragmatic decision to include only published, peer-reviewed evidence in our systematic review. Although it could be argued that studies published in industry-related journals (i.e. the grey literature) would have provided a broader review of the available evidence, they were not included. This was because there is no agreed method of pooling evidence obtained from this literature, in addition to articles not having been subject to scrutiny, which could have substantially reduced the quality of our findings. 

We started the systematic review process in early 2016 and last updated our searches in March 2018⁷. Overall, two studies that evaluated PSAPs met eligibility for inclusion. No studies were deemed eligible that evaluated other new and emerging devices, such as smartphone apps or made-for-smartphone hearing aids.

Studies included in the review primarily examined speech in noise performance, with pooled data across the two studies assessing PSAPs^{3, 8} showing a beneficial effect, whereby speech intelligibility was improved in comparison to unaided conditions.

Our estimates of effect were relatively conservative, given that we pooled data across all five PSAPs included in one study that varied in terms of purchase price, from $29.99 to $349.99³. It should also be noted, however, that this study showed that hearing aids were superior to PSAPs that cost less than $269.99, but performance was equivalent for hearing aids and PSAPs costing more than $299.99. This might be attributable to the finding that “premium” priced PSAPs show comparable electroacoustic characteristics to hearing aids⁴. 

In our systematic review, we also assessed the quality and risk of bias for each included study. The evidence included was judged to be of poor to good quality, and subject to bias due to limitations in study design. Specifically, all included studies employed a before-after comparison design, which did not include a separate control group. As a result, it cannot be known for certain whether other factors contributed to the observed findings.

Our recommendation, therefore, was that high-quality evidence in the form of randomized controlled trials are required to demonstrate the effectiveness of alternative listening devices. A randomized controlled trial design is desirable, as it is the most rigorous experimental means of establishing cause-and-effect relationships. 

A recent, and particularly relevant, example of this type of design in the hearing literature is the randomized, double-blind, placebo-controlled trial published by Prof. Larry Humes and colleagues⁹. In this study, hearing aids fitted by an audiologist or using an OTC model were compared in adults with mild to moderate hearing loss. Speech recognition and hearing aid benefit did not differ between the different types of delivery model. However, hearing aid satisfaction and percentage likely to purchase hearing aids at the end of the trial were lower for the OTC model, which might be attributable to the lack of audiological input. 

Evaluating Hearing Aid Alternatives

Although the evidence provided by Humes and colleagues is a noteworthy step in the right direction, you might be left wondering, to what extent these findings can generalize to other devices and/or hearing healthcare settings. To begin to address this, we undertook a mixed-methods study to assess the usability of a range of alternatives to conventional hearing aids^{10, 11}.

Existing hearing aid users trialed one of the following four smartphone-connected listening devices:

1. PSAP,
2. Hearing aid app with hearable (wireless earphones)
3. Hearing aid app with wired earphones
4. Made-for-smartphone hearing aid

All devices trialed could be fitted and/or fine-tuned via an accompanying smartphone app. Our study was novel because a range of different devices were trialed for a period of two-weeks in the real-world. Participants completed self-report questionnaires and a semi-structured interview. The latter was designed to gain an in-depth insight into the views of adults living with hearing loss toward a range of smartphone-connected alternative devices when used in everyday life away from the laboratory.  

In comparison to conventional hearing aids, we found that self-reported use, benefit, satisfaction, and usability were rated highest for made-for-smartphone hearing aids. Although these outcomes were lower for the remaining devices studied, the smartphone hearing aid app with wired earphones was also rated highly. The lowest performing devices were the PSAP and smartphone hearing aid app with hearable.

Furthermore, results from the semi-structured interviews suggested that, irrespective of the device trialed, all participants reported that the ability to adjust their sound settings using an accompanying smartphone app provided them with a greater sense of control and reduced perceived stigma. This functionality also led to greater social participation and less frustration, with one participant reporting, “It gives me that bit of control, and it’s not other people running my life, it’s me. It’s not quality of life, it’s just having a life”.

Importantly, individuals commented that these devices would have encouraged them to seek help for their hearing loss from an earlier age. 

Our results weren’t all positive, however, with some users experiencing difficulties adjusting and/or pairing the device with their smartphone. Nevertheless, they stated that these issues could easily be resolved through the provision of accompanying instructional information, such as a YouTube video.

We also recognize the importance of supplementary information to support successful device use. Mel Ferguson and colleagues have developed a series of multimedia videos (or reusable learning objects, RLOs) for first-time hearing aid users, branded C2Hear. Following a participatory design approach involving adults with hearing loss and audiologists¹², the effectiveness of the RLOs was assessed in a randomized controlled trial¹³. The trial showed a range of benefits for first-time hearing aid users who accessed the RLOs versus a waiting list control.

These benefits included greater knowledge of hearing aids and communication, better hearing aid handling skills, and higher hearing aid use in suboptimal users. We have further shown that C2hear increases self-efficacy for hearing aids, with large clinical effect sizes¹⁴.

Following the trial, at the end of 2015 C2Hear was made freely available on YouTube and has received around 200,000 global views to date (42% from the US). A new stand-alone ‘go-to’ website is currently being finalized and will be launched in summer 2019 (www.c2hearonline.com). The new website will include all C2Hear developments, as well as other resources, such as newsletters and journal articles. 

More recently, the findings of our usability study have been replicated and extended in another assessing a prototype hearing aid app used in conjunction with a made-for-smartphone hearing aid¹⁵. Outcomes were assessed in both first-time and existing hearing aid users. In this latest study, we found significant improvements in social participation, hearing-related fatigue, quality of listening through hearing aids, and hearing aid benefit and satisfaction.

Most participants reported that the smartphone app met their needs ‘extremely’ or ‘very well’. The app was found to provide the greatest benefit for conversations in noisy environments and the most useful feature of the app was the ability to make user-centered adjustments to the quality of the sound when conversing in background noise. 

Taken together, these usability studies suggest that user-controllability empowers adults to self-manage their hearing loss, providing them with a greater sense of confidence, which leads to greater participation. Our studies show that smartphone-connected devices are beneficial for adults with mild to moderate hearing loss. We also need to consider the impact of these devices on other key stakeholder groups (e.g. NHS audiologists, independent sector) that will also be affected by new and emerging technologies. Given their clinical expertise, hearing healthcare professionals can offer an alternative but equally valid point of view that also requires consideration. 

In March 2019, led by Dr. Anne Olson (University of Kentucky), we completed a study investigating the views of UK hearing healthcare professionals (publicly-funded National Health Service and independent sector) toward new technologies and how they should be delivered¹⁶. A three-round, online Delphi survey was completed that aimed to gather consensus from a group of experts on this topic.

Preliminary results suggest that hearing healthcare professionals agree that appropriate candidates for new and emerging devices should include adults (but not children) reporting communication difficulties that have no medical contraindications and sufficient digital literacy. There was some ambivalence concerning the role of new and emerging devices if provided via the internet or a non-audiological healthcare provider.

While these delivery models might improve accessibility, there were concerns about patient’s ability to accurately assess their hearing loss, as well as delays they might experience in the treatment of other medical conditions. Subsequently, this study highlights several areas of agreement across UK hearing healthcare providers and identifies how new service delivery models for new and emerging devices might be developed and piloted in the future.

Where do we go from here?

Given that by 2020 hearing aids in the US will be available over-the-counter without a hearing healthcare consultation, audiologists need to be prepared to respond and adapt their practices. Moreover, it is essential that professionals are aware of the best available evidence. As I have already argued, such research evidence is desperately needed when considering whether technological advances that enable new service delivery models can truly benefit adults living with mild to moderate hearing loss. 

The developmental work that we and others have completed, and which I have outlined in this blog, should be used as a starting point to inform the design of future high-quality research studies in this area. To provide such evidence, researchers, hearing healthcare professionals and policy makers all need to collaborate to develop and evaluate approaches that incorporate new devices into current clinical practices.

With high-quality evidence, we will have a greater confidence in the benefits provided by alternative devices, including OTC hearing aids, as well as whether they can revolutionize hearing health care service delivery.

Acknowledgements

The research presented was undertaken by members of the Mild to Moderate Loss team at the National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre led by Dr. Mel Ferguson. 

Declaration of Interest

The author reports no conflict of interest. The author alone is responsible for the content and writing of the blog. This blog presents independent research funded the NIHR. The views expressed are those of the authors and not necessarily those of the UK NHS, the NIHR or the Department of Health and Social Care.

References

1. Ferguson, M.A., et al., Hearing aids for mild to moderate hearing loss in adults. Cochrane Database Syst Rev, 2017. 9(9 ): p. CD012023.
2. The National Academies of Sciences Engineering & Medicine, Hearing healthcare for adults: priorities for improving access and affordability. 2016, Washington, DC.
3. Reed, N.S., et al., Personal sound amplification products vs a conventional hearing aid for speech understanding in noise. JAMA, 2017. 318(1): p. 89-90.
4. Reed, N.S., et al., Pilot electroacoustic analyses of a sample of direct-to-consumer amplification products. Otology & Neurotology, 2017. 38(6): p. 804-808.
5. Amlani, A.M., et al., Utility of smartphone-based hearing aid applications as a substitute to traditional hearing aids. The Hearing Review, 2013. 20(13): p. 16-18.
6. Maidment, D.W., et al., The effectiveness of alternative listening devices to conventional hearing aids for adults with hearing loss: a systematic review protocol. BMJ Open, 2016. 6: p. e011683.
7. Maidment, D.W., et al., A systematic review and meta-analysis assessing the effectiveness of alternative listening devices to conventional hearing aids in adults with mild-to-moderate hearing loss. International Journal of Audiology, 2018. 57(10): p. 721-729.
8. Sacco, G., et al., Clinical evaluation of an over-the-counter hearing aid (TEO First) in elderly patients suffering of mild to moderate hearing loss. BMC Geriatrics, 2016. 16(136).
9. Humes, L.E., et al., The effects of service-delivery model and purchase price on hearing-aid outcomes in older adults: a randomized double-blind placebo-controlled clinical trial. American Journal of Audiology, 2017. 26: p. 53-79.
10. Maidment, D.W., et al., Applying the COM-B model to assess the usability of smartphone-connected listening devices in adults with hearing loss. Journal of the American Academy of Audiology., 2019. 30(5): p. 417-430.
11. Maidment, D.W. and M.A. Ferguson, An application of the UK Medical Research Council’s guidelines for evaluating complex interventions: a usability study assessing smartphone-connected listening devices in adults with hearing loss. American Journal of Audiology, 2018. 27(3S): p. 474-481.
12. Ferguson, M., et al., Development of a multimedia educational programme for first-time hearing aid users using a Delphi Review and participatory approach. International Journal of Audiology, 2018 57(8): p. 600-609.
13. Ferguson, M.A., et al., A randomized controlled trial to evaluate the benefits of a multimedia educational programme for first-time hearing aid users. Ear & Hearing, 2016. 37(2): p. 123-136.
14. Gomez, R. and M.A. Ferguson, Improving knowledge and self-efficacy for hearing aids self-management: the early delivery of a multimedia-based education program in first-time adult hearing aid users. International Journal of Audiology, submitted.
15. Habib, A., et al., What are the benefits of smartphone-connected hearing aids in first-time and existing NHS hearing aid users? British Academy of Audiology, 2019. Summer Magazine.
16. Olson, A., et al., Exploring new and emerging devices and service delivery models for self-management of hearing loss in adults: a Delphi review, in The Fourth International Meeting on Internet & Audiology. 2019: University of Southampton, United Kingdom.

David Maidment, PhD,  is a Lecturer in Psychology, School of Sport, Exercise and Health Sciences, at Loughborough University.  Dr. Maidment studied within the School of Psychology at Cardiff University, graduating in 2008 with a BSc (Hons.), MSc (2009) and PhD (2013) in Applied Psychology, exploring how different modes of speech interact in verbal short-term memory. After his PhD, Dr. Maidment worked as a Research Associate (2012-2015) at the Medical Research Council (MRC) Institute of Hearing Research, and then as a Research Fellow (2015-2018) at the National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre (BRC). Dr. Maidment is now a Lecturer in Psychology within the School of Sport, Exercise and Health Sciences at Loughborough University. His research interests currently focus on novel intervention strategies to improve the quality of life of people living with hearing loss. Dr. Maidment has been involved in the development and assessment of a personalised, internet-based educational programme (C2Hear Online), which aims to improve practical hearing aid handling and communication skills in first-time hearing aid users. He has also collaborated with the Danish-based Ida Institute to evaluate their online Telecare Tools to facilitate patient-centred care in NHS hearing appointments. More recently, David has undertaken several projects assessing new and emerging technologies for hearing loss, including smartphone-connected listening devices.