Go Figure: I Didn’t Know I Could Successfully Fit Patients with Normal Audiograms

Author: Brian Taylor, Au.D.

Many audiologists politely cringe when confronted with the possibility of fitting hearing aid on a person with normal hearing. On the surface, after all, fitting someone with normal hearing doesn’t make much sense: how could someone benefit from amplification when their hearing thresholds are normal. And, even if you did fit them, they are likely to complain of circuit noise, or worse yet, the maximum output could cause a permanent threshold shift if set too high. Recent hearing aid sound quality improvements, combined with fresh thinking about the limitations of the pure tone audiogram and auditory wellness have changed this mindset.

It is clear, today, that successful outcomes can be obtained for those with normal audiograms when fitted with modern hearing aids. This statement is supported by evidence, illustrated in the Figure, which comes from Humes (2020).

Here, the means and standard deviations for the Hearing Handicap Inventory for the Elderly (HHIE) are shown for unaided and aided conditions with the difference shown as the benefit received. Note the higher the bar in the Figure, the worse the self-reported communication difficulty as measured by the HHIE. Also note there is a companion version of the HHIE, called the HHIA (A is for adults), intended to be used with adults of working age. Both the HHIA and HHIE, along with a revised version, the Revised Hearing Handicap Inventory (RHHI), are essentially interchangeable. Since the family of HHIE/A questionnaires are not copywritten, we have printed the screening version at the end of this article. This is the version that most clinical audiologist opt to use.

The top panel shows the results for those fit using audiology best-practices fitting (AB) and the bottom panel a consumer-decides (CD) try-and-select self-fitting method. Recall that Humes, et al (2017) published a landmark study that compared outcomes from these two groups. As part of that study, individuals in the Bloomington, Indiana area were recruited to participate in this study. As most private practice audiologists know, it is relatively common for a modest number of people with normal hearing and self-reported hearing difficulties to respond to these types of ads. Historically, when individuals presented to the clinic with a normal audiogram, even though they may self-report communication problems, they were not considered candidates for hearing aids. The data reported in the Figure should change that thinking in a couple of different ways.

The data shown in the Figure are striated by the degree hearing loss, and several remarkable points are clinically relevant. First, notice the HHIE benefit, unaided score minus aided score, is about the same in both panels and across all hearing loss groups, including the group with normal audiograms. Given the comparable benefit measured across hearing-loss groups in both the AB and CD panels, this finding suggests those with “normal hearing” show measurable benefit that is on par with individuals in mild and moderate hearing-loss groups.

Second, the HHIE, a validated self-report which measures the impact hearing loss has on daily activities, identifies people who struggle with communication and could benefit from amplification. Even though their pure-tone audiograms were in the normal-hearing range, many individuals in this group perceived communication problems, as shown by the unaided HHIE scores in this figure. Interestingly, these communication problems as noted on HHIE were about the same magnitude as those reported by individuals with mild or moderate hearing loss. Moreover, all the individuals in this study were first-time hearing aid purchasers – exactly the type of people who sometimes respond to advertising but are then told by the audiologist they didn’t have enough hearing loss to warrant the use of amplification.

There are several key considerations gleaned from the Figure. One, the HHIE, including the shortened 10-question screening version, validly measures self-reported difficulty and ought to be administered to all help seeking patients. Further, it is advisable to administer the HHIE before and after fitting to generate a measure of relative benefit. As Humes and Weinstein (2021) suggest, the HHIE/A are effective tools that gauge the auditory wellness of individuals, and provide valuable insight on the functional abilities of the individual, often missed by the pure tone audiogram.

Two, individuals who are motivated to try hearing aids, and score poorly on the HHIE/A should be considered candidates for amplification – even when their audiograms are normal. As Edwards (2021) pointed out in a recent video course, restoring audibility by following best practice fitting guidelines results in real world benefit for patients with normal audiograms, when they are motivated to use hearing aids and self-report hearing difficulty. Three, audiologists should be mindful that the traditional audiogram has a normal range of 30 dB with a limited bandwidth of relatively 8000 Hz. A sizeable number of patients with self-reported hearing difficulties have substantial hearing loss at frequencies above 8000 Hz when tested. It is also common that many patients with normal audiograms may have experienced a drop from thresholds better than zero to 20; thus, their audiogram is within normal limits, but their hearing has shifted by more than 20 dB. Given the limitations of the traditional pure tone audiogram, audiologists should include other more objective testing in their repertoire, including extended high frequency pure tone testing and speech intelligibility in nose testing that may uncover communication deficits.

Fourth, based on the similar outcomes between the AB and CD panels in the figure, individuals who opt to self-fit their hearing aids and purchase amplification over the counter (OTC) could potentially experience the same level of outcome as those who seek the guidance of an audiologist. For the right person, OTC might be a viable option that results in reasonably good outcomes. Fifth, recent advances in hearing aid technology result in low distortion amplification, reduction of the occlusion effect and improved audibility of soft inputs – critical improvements in sound quality that improve the probability that people with normal audiograms can be fit successfully with hearing aids.    

Edwards, B (2022) Soundbites S03E01: To fit or not to fit! Strategies for fitting no-to-mild hearing losses. https://www.youtube.com/watch?v=jItGZqAxXVs

Humes, L.E. (2020). What is normal hearing for older adults and can “normal-hearing older adults” benefit from amplification? Hearing Review, 27(7), 12-18

Humes, L.E., Rogers, S.E., Quigley, T.M., Main, A.K., Kinney, D.L., & Herring, C. (2017). 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, 26, 53-79.

Humes, L.E. & Weinstein, B.E. (2021). The need for a universal hearing metric-is pure-tone average the answer? JAMA Otolaryngology-Head & Neck Surgery, Published online April 15, 2021. 10.1001/jamaoto.2021.0417