Program Chair
The Quiet Coalition
A program of Quiet Communities, Inc.
P.O. Box 533
Lincoln MA, USA

Popular version of 4aPP11 – Moderate to severe hearing loss is not part of normal aging
Presented at the 189th ASA Meeting
Read the abstract at https://eppro02.ativ.me/appinfo.php?page=Session&project=ASAASJ25&id=3981686&server=eppro02.ativ.me

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Is hearing loss in older people normal? It certainly is common, but the radical conclusion proposed in this summary paper is that it isn’t part of normal aging. Hearing loss in older people, technically called presbycusis or age-related hearing loss, is really the result of exposure to too much noise over one’s lifetime. The hearing loss common in old age is entirely preventable by reducing exposure to loud noise. Figure 1 shows how too much noise causes hearing loss by damaging the hair cells in the cochlea in the inner ear.

Figure 1. Top: Auditory structures from external ear (pinna) to auditory nerve. Bottom: Normal and damaged hair cells. From Centers for Disease Control and Prevention. How does loud noise cause hearing loss?

Why does this matter? If something is caused by normal aging, like thinning gray hair, nothing can be done about it. But if a condition common in old age is due to something that can be changed, like diet, exercise, or avoiding harmful exposures, maybe it can be delayed or prevented entirely.

Many conditions common in older people, once thought to be due to normal aging, have been shown to be preventable. These include obesity, diabetes, high blood pressure, muscle weakness, heart disease, skin cancers, and even dementia. Age-related hearing loss should be added to this list.

A number of studies done in the 1960s in isolated populations not exposed to loud noise found good hearing preserved to age 70. For example, a study of hearing in the isolated Mabaan population in the Sudan published in 1962 found good hearing preserved to age 70. Figure 2 shows that anything more than a 10-decibel hearing loss may not be normal.

Figure 2. Hearing loss in women and men in industrial societies and the non-industrialized Mabaans. Adapted by Kathleen Romito MD from Figure 11 in Kryter KD. Presbycusis, sociocusis and nosocusis. J. Acoust. Soc. Am. 1 June 1983; 73 (6): 1897–1917. https://doi.org/10.1121/1.389580.

Other lines of evidence supporting the conclusion that hearing loss in old people isn’t due to normal aging include:

• Occupational studies showing exactly how much noise causes hearing loss. This is the basis of noise exposure limits for workers. Everyone’s ears are the same. If noise causes hearing loss in workers, it has to cause hearing loss in everyone.
• Boys and girls have equal hearing at birth, but by the teen years and into adulthood, women have better hearing than men. [See Figure 2.] Girls and women generally don’t do noisy things like hunting or woodworking, or work in noisy factories or mines or operate heavy equipment.
• Workplace hearing loss occurs in the frequencies the ear is exposed to. For example, dentists have high-frequency hearing loss in the ear nearest the drill.
• How noise damages hearing is well-understood, down to the cellular, subcellular, and molecular levels.

What else could cause age-related hearing loss? Some experts mention drugs that damage the ear, hardening of the arteries, genes that cause hearing loss, or nutritional factors, but seem to ignore or downplay noise. The published evidence, though, doesn’t support a major role for any of these other factors.

Recent research supports the conclusion that hearing loss in older people can be prevented. The upper left-hand graph in Figure 3 shows that normal hearing loss in older people is minimal, about 10 decibels at 4,000 Hertz (cycles per second ) as in Figure 2.

Figure 3. Mean audiograms and standard errors of exemplars (filled symbols) and non-exemplars (open symbols) in four audiometric phenotypes. Reproduced with permission from Dubno JR, Eckert MA, Lee FS, et al. Classifying human audiometric phenotypes of age-related hearing loss from animal models. J Assoc Res Otolaryngol. 2013 Oct;14(5):687-701. https://pmc.ncbi.nlm.nih.gov/articles/PMC3767874/

Why does prevention of age-related hearing loss matter? Hearing aids are expensive. Only one-third of older Americans who might benefit from hearing aids have them. Even in countries where hearing aids are provided by the national health insurance program, many people don’t want them. There is a stigma attached to hearing loss and to wearing hearing aids. Also, hearing aids don’t restore normal hearing and don’t work as well as desired in noisy restaurants or at parties,

CDC states that noise-induced hearing loss is the only type of hearing loss that is 100% preventable. Preventing age-related hearing loss is simple and inexpensive: reduce lifetime noise exposure. If something sounds loud, it’s too loud, and one’s auditory health is at risk. Turn down the volume, insert earplugs, or leave the noisy environment and you won’t need hearing aids when you get old.

More information can be obtained from the poster at https://virtual.posterpresentations.com/research/presentation/ID279825/.