Tech Topic | February 2023 Hearing Review 

WHO landmark world report on hearings stated the audiogram should not be used as the sole indicator when assessing someone’s hearing ability.

By Brent Edwards, PhD

Abstract

The audiogram is insufficient in determining the hearing difficulties and hearing needs of individuals. People with “normal” audiograms can have significant hearing difficulties and may benefit from hearing aids and other devices. Audiologists should consider additional information such as the responses to self-assessment questionnaires when determining the need for their services and treatment strategies.

For most of the past half-century, the audiogram has been used to determine whether someone needs hearing help and whether they would benefit from a hearing aid. The fact that only 30% of those with a measurable hearing loss (PTA > 25 dB HL) has been used repeatedly to indict the hearing aid industry for not helping the 70% of those with a hearing loss who are presumed to need hearing help. One result of this approach to determining hearing need is that those with what is considered “normal” hearing as indicated by the audiogram (PTA < 25 dB HL) are presumed to not have need for hearing help and to not be able to benefit from hearing aids or other hearing healthcare technologies.

The experiences of hearing healthcare providers, however, suggest that the audiogram is not a sufficient indicator of who needs hearing help. One of the largest hearing healthcare providers in Australia has noted that over 20% of the people who come to its centers are found to have PTAs less than 25 dB HL; these people are told by the audiologist that they have normal hearing and should come back in a few years to see if their hearing has changed, with no offer for help or hearing solutions. This situation is similar in hearing healthcare clinics around the world. This begs the question why these people with “normal audiograms are going to hearing healthcare clinics and expressing concern about their hearing, and whether their needs should be dismissed and solutions denied as is current practice.

There is ample evidence that clinically-measured hearing loss is not highly correlated with self-perceived hearing loss or hearing difficulty. In 1990, Gates et al.1 determined from a large-population study that one in five people who reported that they had a hearing loss actually had a “normal” audiogram. More recently, Curti et al.2 found that 43% of those with a measurable hearing loss (PTA > 25 dB HL) reported having good hearing. The recent World Health Organization (WHO) landmark World Report on Hearing3 stated that the audiogram should not be used as the sole indicator when assessing someone’s hearing ability or need for hearing devices. The influential US Preventative Services Task Force, who assessed whether they should recommend hearing screening for all adults over the age of 50, determined that population-level hearing screening should not be done because measures such as the audiogram are poor indicators of whether someone will find hearing devices helpful. Summarizing this emergent thinking that the audiogram is a poor indicator of whether someone is experiencing hearing difficulty or needs hearing help, Gatlin and Dhar4 called audiogram-based classification of what is “normal” hearing and whether someone has hearing difficulties as “arbitrary and artificial.”

All of this is not to say that the audiogram has no value. It defines quite well what parts of sounds are inaudible and provides a good indication of how much gain to provide in a hearing aid to restore audibility if a hearing aid is fit on someone. What it does not do is provide a good indication of whether someone is experiencing a disability in their life because of their hearing. The WHO has noted that a person’s health and well-being is determined not just by objective diagnostic measures of bodily function and the integrity of its structures but also by the activities that a person participates in as well as personal factors such as personality and environmental factors that can make functioning more challenging and stress health functions that have experienced some insult. For hearing, this means that the effect of a person’s hearing function on their ability and well-being can be affected by how socially active they are, how important communication is in their daily lives, how well they compensate for hearing difficulty through behavior change or cognitive ability, and how challenging the acoustic environment is in which they are trying to listen. All of these factors influence whether someone’s hearing is affecting their lives and whether they can benefit from hearing services and hearing technology.

Humes5 has suggested that a self-assessment tool such as the Hearing Handicap Inventory for the Elderly – Screening questionnaire can be used to determine the need for hearing help. Edwards6 has also argued that there is a large population of people without a measurable hearing loss but with self-perceived hearing difficulty that could benefit from hearing solutions. What solutions might benefit someone with a “normal” audiogram but self-assessed hearing difficulty is unknown and the lack of a validated solution has been a deterrent to acknowledging the need of this population for hearing help.

The National Acoustic Laboratories (NAL) has been working to determine what solutions might help this underserved population. Over the past several years, NAL researchers have investigated the benefits of traditional hearing aids and non-traditional hearing devices (hearables) in addressing the hearing problems of people with self-assessed hearing difficulty but minimal hearing loss. Several papers are under review in peer-reviewed journals detailing the results from these studies, but a summary of the results is that all of the solutions tested have benefited some of the participants, such that they experienced improvements in their lives and wanted to continue using the devices after the study ended. All participants had PTAs less than 10 dB HL, yet they were satisfied wearing hearables, such as Apple’s AirPods Pro, and even traditional receiver-in-the-canal hearing aids. The data suggests that there was a preference for hearing aids over hearables because the hearing aids were more comfortable and less visible to others while providing similar if not superior understanding of speech in noise.

The results from NAL’s studies and those of others demonstrate that the large number of people who are seeking hearing help yet being told they have normal hearing and turned away at hearing healthcare clinics could actually be experiencing hearing disability and may benefit from hearing devices. Which devices to fit, how to fit these devices, what gains to provide, what features to activate and when the devices should be used are still not well understood and deserves further investigation. But what is clear is that someone’s hearing needs should not be solely determined by the audiogram and solutions should be offered to people who express that they have hearing difficulty even though they have minimal measurable hearing loss. 

Acknowledgements

The author wishes to acknowledge Joaquin Valderrama-Valenzuela, Nicky Chong-White, and Jorge Mejia who’s research at NAL contributed to these findings.

Citation for this article: Edwards B. Providing Hearing Solutions to People with Hearing Difficulties but Minimal Hearing Loss. Hearing Review. 2023;30(2):22-23

References

  1. Gates GA, Cooper JC, Kannel WB, et al. Hearing in the elderly: the Framingham cohort, 1983-1985. Part I. Basic audiometric test results. Ear Hear. 1990;11(4):247-56.
  2. Curti SA, Taylor EN, Su D, Spankovich C. Prevalence of and Characteristics Associated With Self-reported Good Hearing in a Population With Elevated Audiometric Thresholds. JAMA Otolaryngology Head Neck Surgery. 2019;145(7):626-633.
  3. World Health Organization. World report on hearing. World Health. Organization. 2021.
  4. Gatlin AE, Dhar S. History and Lingering Impact of the Arbitrary 25-dB Cutoff for Normal Hearing. American Journal of Audiology. 2021;30(1):231-234.
  5. Humes LE. An Approach to Self-Assessed Auditory Wellness in Older Adults. Ear Hear. 2021; 42(4):745-761.
  6. Edwards B. Emerging Technologies, Market Segments, and MarkeTrak 10 Insights in Hearing Health Technology. Seminars Hear. 2020; 41(1):37-54.