May 2021 The Hearing Journal
Hearing health care providers likely agree on the following evidence-based conclusions: (1) Hearing loss is under-recognised, undervalued, and under-treated; (2) the socioeconomic burden of hearing loss is high; (3) hearing aids assist in overcoming the psychosocial burden posed by communication difficulties in challenging listening situations; (4) hearing aid use is greatest for individuals with significant hearing impairment; and (5) stigma is a powerful reason hearing aids are underutilised. Health care providers, however, do not agree on the potential for the Over-the-Counter (OTC) Hearing Aid Act of 2017, which will allow for direct-to-consumer access, to remove barriers to hearing health care utilisation and access. Nor is their agreement regarding the criteria for candidacy for OTC hearing aids. When signed into law, the FDA Reauthorisation Act indicated that this new category of devices will be marketed for persons with “self-perceived mild-to-moderate hearing loss” without the need for a prescription or involvement of a licensed professional. But what is really meant by “self-perceived mild-to-moderate hearing loss”? Let's unpack the terminology in this legislation that remains a source of confusion.
WHAT IS MEANT BY ‘SELF-PERCEIVED MILD-TO-MODERATE HEARING LOSS’?
When I first heard about the legislation, my focus was on the confusion likely prompted by the verbiage describing candidacy. A recent viewpoint piece by Lin and Reed rekindled my concerns. The term “perceived” contained in the legislation suggests that the involvement of hearing care specialists in the process is not a prerequisite, yet the term “mild-to-moderate” suggests the involvement of a hearing health care specialist to quantify the severity of hearing impairment. Given the mixed message communicated by the language, questions are likely to arise regarding eligibility as it relates to hearing status and the need to take action. Hence, it was timely that Lin and Reed advocated for a universal hearing health care metric that would communicate to non-audiologic professionals information about the hearing status and communicative needs of people with hearing loss.
Lin and Reed argued that the “gold standard” for describing hearing status should be average air conduction thresholds at 500, 1000, 2000, and 4000 Hz, the frequencies most important for understanding speech. They reasoned that the universality, clinical meaningfulness, and scientific importance of the PTA4 would serve as an excellent anchor point when discussing treatment options. They also suggested that the PTA4 would enable stakeholders to contextualise the potential risk of adverse events associated with hearing loss and would therefore be preferable to using traditional categorical labels such as mild, moderate, or severe hearing loss. Finally, Lin and Reed suggested that knowledge of one's PTA4 would be helpful when explaining hearing status to others.
BUT WHAT ABOUT PEOPLE WITH ‘HIDDEN HEARING LOSS’?
One concern about their proposed metric is that it does not convey information about the communicative status for individuals with normal peripheral hearing who express a preference for quiet settings when conversing with others, who are disappointed to learn that they have a normal audiogram yet experience difficulty communicating with others in noisy situations. Hidden hearing loss, a problem aggravated by age and noise exposure, is not uncommon and likely has a physiologic basis. In his discussion of candidacy for OTC hearing aids, Edwards estimated that out of 37.4 million U.S. adults with self-reported hearing difficulties, approximately 25.3 million actually have normal audiometric hearing thresholds. Koerner, Papesh and Gallun conducted a survey of audiologists working in a variety of settings designed to uncover reported speech understanding and hearing difficulties of normal-hearing individuals. Forty-five percent of audiologists who responded to the survey reported seeing between one to three patients per month with normal or near-normal PTAs who had communication difficulties, and 23% of respondents indicated seeing more than four patients per month who have communication difficulties despite having normal or near-normal PTAs. Interestingly, respondents indicated that 35% of their patients were dissatisfied when they learned that their PTAs were normal, and 32% were satisfied when learning that their PTAs were in the normal range. These data underscore that it is not uncommon for audiologists to encounter persons with normal hearing and auditory complaints who seek professional assistance for communicative challenges. Using a population approach, Tremblay et al. examined data from the Beaver Dam Offspring Study (BOSS) to determine how frequently “the paradox” occurs in the general population wherein persons with normal hearing thresholds experience communication difficulties. Of the 682 participants whose pure-tone thresholds fell within normal limits, 82 (12%) of the respondents self-reported having hearing difficulties. Notably, audiometric thresholds were not significantly different for the group reporting hearing difficulties (HD) as compared to those not reporting hearing difficulty, nor were word-recognition scores in quiet and in competing noise. Variables associated with self-reported HD included low income, increased noise exposure, higher likelihood of depression, reduced visual function, and greater likelihood of having seen a physician for hearing difficulties. The presence of a subclinical medical condition among persons with clinically normal audiograms who complain of auditory difficulties (e.g., those with mild traumatic brain injury) further highlights the shortcoming of relying exclusively on the PTA4 as a universal metric. Knoll et al. uncovered auditory symptomatology and self-reported hearing handicap in close to 40% of individuals in their sample with normal audiometric thresholds. Since patient-reported auditory complaints are common among people with TBI and normal hearing thresholds, the PTA4 would fall short in helping to manage persons with TBI and normal hearing, yet present with symptomatology ranging from subjective hearing difficulties and tinnitus to aural fullness or hyperacousis.
I wholeheartedly agree with Lin and Reed who stated that the PTA4 only reflects one aspect of auditory function, namely audibility. I would argue that while audibility imperfectly relates to self-rated hearing difficulties (SRHD), the latter metric holds promise as a potential metric as SRHD relates strongly to important health indicators including activation levels, self-rated health, and help-seeking. The fact that the disparity in prevalence estimates using behavioural estimates of hearing loss severity as opposed to self-reported hearing difficulties appears to decrease somewhat with increasing age, coupled with the finding that the odds of people self-reporting hearing difficulty is higher for those who self-report trouble hearing in noise, may lend support to the potential of some form of self-report as a metric.
How patients self-assess the communication challenges that relate in part to sensory decline is integral to healthy ageing or the process of developing and maintaining functional ability (i.e., the ability to be and do what people value) that ultimately enables well-being in old age.10 Our ability to communicate effectively is at the heart of healthy ageing, and a clinically meaningful and relevant metric of hearing/communicative function could add value to our armamentarium just as self-rated health is an important indicator of health behaviour in public health circles. The reality for clinicians to ponder is this: Which metric will motivate individuals to take action as effective and informed managers of their hearing health? Stated differently: Which universal metric will empower people with hearing difficulties to take action for their hearing wellness and pursue an OTC device or hearing aids via the more traditional route?