Amyn Amlani, PhD
by Amyn Amlani, PhD
The reality of over-the-counter (OTC) products becoming federally regulated took one step closer to certainty last week. The FDA Reauthorization Act of 2017 (HR 2430), which includes provisions for OTC hearing aids for adults with perceived mild-to-moderate hearing loss, passed successfully through the US House of Representatives in July 2017 and through the US Senate in August 2017, and was signed into law by President Trump late last week.
While this bill will improve consumer access to a low-cost alternative to traditional hearing aids, the literature on OTC performance and patient outcome is still in its infancy. In fact, the preconceived notion—from the provider side—is that OTC devices are inferior in performance to traditional hearing aids, and thus performance and patient outcomes will be compromised compared to a traditional hearing aid.
In this post, we take a closer look at the existing literature on OTC electroacoustic performance, and how these electroacoustic data influence behavioral performance for devices fit by an experienced practitioner. The findings from the literature are then cast to provide insight into what the future holds for the hearing aid market.
Electroacoustic Performance
There is a growing body of research on OTCs and hearing aids that indicates, “You get what you pay for.”1-5
In general, OTC devices and traditional hearing aids that retail for less than $150 and $500 per unit, respectively, tend to yield unacceptable levels of equivalent input noise (EIN) and total harmonic distortion based on ANSI standards for traditional hearing aids. These same, economically-priced devices provide insufficient high-frequency amplification and too much low-frequency amplification for moderate degrees of hearing losses relative to a prescriptive target.
For OTC devices and hearing aids retailing for more than $150 and $500 per unit, respectively, the literature indicates that most devices provide acceptable electroacoustic tolerance levels relative to the ANSI standards for traditional hearing aids. These same, premium-priced devices tend to yield appropriate levels of amplification for moderate degrees of hearing losses relative to a prescriptive target.
Behavioral Data
Economy Line OTC Data
Based on the categorical findings of the electroacoustic data, the data suggest that economy line OTC devices (i.e., priced under $150) are inferior to traditional hearing aids.
To validate this notion, Amlani and colleagues6 compared participant responses of sound-quality attributes (e.g., comfort, clarity, intelligibility) in three listening conditions:
- speech recorded in quiet
- speech recorded against multitalker babble at a +4 signal-to-noise-ratio
- speech recorded in a echoic environment having a reverberation time of 1.17 sec
for four amplification products:
- the participant’s own premium level device (i.e., retail price > $2600 per unit)
- an economy level hearing aid (i.e., retail price < $300 per unit)
- a smartphone-based hearing aid application
- an economically priced OTC device (i.e., retail price < $150 per unit).
For each sound-quality attribute measured, and in all three listening conditions, the OTC product (product #4) was rated poorest compared to the other amplification products. This finding was highly correlated with the fact that the gain for the OTC product differed from the participant’s premium-priced hearing aid (product #1), which was programmed and verified to a prescriptive target, by an average of 13 dB in the high frequencies (between 2000 Hz and 6000 Hz).
Our finding of reduced performance/preference with less expensive OTCs has also been reported by others.7,9
Premium Line OTC Data
Conversely, the literature shows that premium OTC devices (i.e., priced above $150) tend to provide similar performance to traditional hearing aids. Rønne and Rossing,7 for instance, found similar sound-quality preferences between a premium traditional hearing aid and a premium OTC product.
Xu et al8 compared aided sound-quality preferences between two traditional, premium level hearing aids and two premium OTC products using a paired-comparison approach for three listening conditions: speech in quiet, speech in noise, and music. Results revealed that the OTC products performed as well as hearing aids for speech in noise and music, but not speech in quiet.
More recently, Reed and colleagues9 compared speech understanding in noise for a hearing aid and five OTC products (4 premium, 1 economy). Results revealed similar speech understanding performance between the hearing aid and the three most expensive OTC products (i.e., retailing at prices > $299.99). Speech understanding performance declined for the two lower prices OTC products. Specifically, speech understanding performance with a OTC product retailing at $269.99 was reduced compared to the traditional hearing aid and three, more expensive OTC products. The lowest price OTC device, retailing at $29.99, significantly degraded speech understanding ability compared to all other amplification products.
Implications
Like it or not, OTC products are here and they will be a disruptive force to the existing marketplace. OTCs have the opportunity to enhance the marketplace through increased awareness of hearing desensitization; increased need for regular audiological maintenance and the need for hearing protection in certain noisy environments; and a means for the public to reduce its stigmatism towards hearing aids.
However, to enhance this opportunity to grow adoption rates of audiological services and technology, there is a critical need to define minimum standards of electroacoustic characteristic performance of OTC products entering the market.
The literature review to date suggests that to meet this standard, the retail price floor for OTCs resides around $300 per unit.
To meet this minimally acceptable electroacoustic standard at this retail price point, it is imperative that economy-priced OTC manufacturing firms increase production costs to provide a standardized product. Any tomfoolery by manufacturers to circumvent a high standard in production and design will negate the opportunity for growth in this market.
Assuming that the manufacturing standards are adhered to, providers who fit their patients with OTC devices in their practices can expect roughly a 5% to 7% increase in first-time users entering the market, with a conversation rate of about 30% of OTC users transitioning to traditional hearing aids on an annual basis. The lag time from OTC purchase to traditional hearing aid adoption is a bit tricky to estimate mathematically given that this event is a first in our professional evolution. However, using optometric data for eyeglass reader to prescriptive lens, the best guess for a lag time appears to be between 18 and 30 months.
References
- Cheng CM, McPherson B. (2000). Over-the-counter hearing aids: Electroacoustic characteristics and possible target client groups. Audiology, 39: 110-116.
- Callaway SL, Punch JL. (2008). An electroacoustic analysis of over-the-counter hearing aids. American Journal of Audiology, 17, 14-24.
- Chan ZY, McPherson B. (2015). Over-the-counter hearing aids: A lost decade for change. Biomedical Research International: 827463.
- Smith C, Wilber LA, & Cavitt K. (2016). PSAPs vs hearing aids: An electroacoustic analysis of performance and fitting capabilities. Hearing Review, 23(7):18.
- Reed NS, Betz J, Kendig N, Korcak M, & Lin FR. (2017). Personal sound amplification products vs. a conventional hearing aid for speech understanding in noise, Journal of the American Medical Association, 318: 89-90.
- Amlani AM. (2017). Sound-quality ratings of traditional and over-the-counter amplification products obtained under real-world- and laboratory-listening conditions. Invited presenter, British Society of Audiology, Harrogate, United Kingdom, June 29-30.
- Rønne F, Rossing R. (2016). Are hearing aids the better rehabilitative choice when compared to PSAPs? Hearing Review, 23(11): 26.
- Xu J, Johnson J, Cox R, Breitbart D. (2015). Laboratory comparison of PSAPs and hearing aids. Paper presented at: Annual meeting of the American Auditory Society, Scottsdale, Arizona, March 5-7. Available at: https://www.harlmemphis.org/files/9814/2593/1864/XuAAS2015_PSAPs.pdf
Amyn M. Amlani, Ph.D., is Professor and Chair of the consortium program in Audiology & Speech Pathology between the University of Arkansas for Medical Sciences and the University of Arkansas at Little Rock. Dr. Amlani holds the B.A. degree in Communication Disorders from the University of the Pacific, the M.S. degree in Audiology from Purdue University, and the Ph.D. degree in Audiology/Psychoacoustics (minor in Marketing and Supply Chain Management) from Michigan State University. His research interests include the influence of hearing aid technology on speech and music; economic and marketing trends within the hearing aid industry; and playing bass guitar in various heavy metal cover bands. Email: [email protected]
feature image from eski paper
I read your number 7 reference: Rønne F, Rossing R. (2016). Are hearing aids the better rehabilitative choice when compared to PSAPs? Hearing Review, 23(11): 26…and found that your conclusion contradicts the actually results found in the study. You wrote: “…the literature shows that premium OTC devices (i.e., priced above $150) tend to provide similar performance to traditional hearing aids. Rønne and Rossing,7 for instance, found similar sound-quality preferences between a premium traditional hearing aid and a premium OTC product.”
The actual conclusion the in the Hearing Review is this:
On the most important domains, speech intelligibility, it was shown that the hearing aid performed significantly better than both PSAPs. Relative to sound quality, the hearing aid was also on average preferred over both PSAPs, although one PSAP (SWS) was preferred equally often as the hearing aid on a subset of sound samples. Thus, it seems fair to conclude that, on speech intelligibility and sound quality, the hearing aid is the better rehabilitative choice.”
Therefore, when you used this reference to support the notion that premium PSAPs/OTCs may have similar sound quality to hearing aids, that is false.
Neeru: Many thanks for your comments. I offer three points. First, I did not review or report on the speech intelligibility component from the the Rønne and Rossing article. Second, the authors themselves report that “Relative to sound quality, the hearing aid was also on average preferred over both PSAPs, although one PSAP (SWS) was preferred equally often as the hearing aid on a subset of sound samples [in Experiment A].” Because of the findings in Experiment A, the authors appear to have undertaken Experiment B. The latter experiment, differs in methodology and sample, shows a differing outcome where the hearing aid is perceived as having greater sound quality than the SWS device. I was not clear in delineating the experiment I was referencing when writing thjs paragraph, so I apologize for the confusion. Lastly, the evidence presented in the blog was based on information available up until this time. As the body of literature grows, and as PSAPs become regulated, we’ll have a better idea of the performance capabilities, and sound quality preferences, provided by these devices as compared to traditional hearing aids.