By Barry Keate
Recent studies appear to disagree on trends in hearing loss. A new American Medical Association (AMA) report shows hearing loss declining among working-age adults in the US. But a Brazilian study shows that most adolescents have experienced tinnitus, and 28.8% of test subjects heard continuous tinnitus in the silence of a sound booth.
We’ll get to the bottom of this and explore what it tells us about risk factors for increased hearing loss and tinnitus.
AMA on Hearing Loss
The AMA report appeared in JAMA Otology Head & Neck Surgery and shows that, contrary to expectations, the percentage of working-age people in the US, aged 20 to 69 years, with hearing loss is declining. (1) The report compares the results of the 2011-2012 cycle of the US National Health and Nutrition Survey with results of the same survey in 1999-2004. The National Health and Nutrition Survey is conducted every two years and has been reporting on hearing issues since 1971.
Hearing impairment was defined as average hearing threshold loss greater than 25 dB. This is the level at which a person cannot hear, at least in one ear, a sound about as loud as rustling leaves.
The researchers reported that 15.9% of respondents to the earlier survey had problems with hearing, compared to 14.1% in the recent group. This decrease is large enough that the total number of people with hearing loss decreased slightly, from 28 million to 27.7 million, even though the total population in this age group grew by 20 million in the same period.
A decline in the incidence of hearing loss is surprising primarily because we have long assumed that the explosive growth in headphone and earbud use, which can damage hair cells in the cochlea, would lead to increased permanent hearing loss and tinnitus, especially in the young.
Adolescents in Brazil
No such surprise is found in a report from the University of Sao Paulo School of Medicine in Brazil. This study examined 170
Brazilian students between 11 and 17 years old (2). They completed a questionnaire about their prior experience with tinnitus, potentially risky listening habits, and sensitivity to ordinary sounds. After this, acoustic measurements were taken in a sound booth.
Most -- 54.7% -- reported that they had previously experienced tinnitus, while 28.8% heard continuous tinnitus in the sound booth. Acoustic properties of their tinnitus correspond to those of chronic adult tinnitus sufferers. Hearing threshold losses averaged 15 dB and did not differ between adolescents reporting or not reporting tinnitus in the booth. Loudness discomfort levels did differ, averaging 11.3 dB lower in adolescents experiencing tinnitus.
While risky listening habits were nearly universal, those with tinnitus and reduced sound level tolerance tended to be more protective of their hearing. These symptoms can be early indications of a vulnerability to synaptic injury that is prevalent among adolescents and is expressed following exposure to high level sounds.
Making Sense of It
What can we make of these seemingly contradictory reports? The study in JAMA measures only hearing loss, not tinnitus. And the hearing loss was averaged between people whose age differed by up to 40 years, so the older subjects would most likely have more hearing loss.
The Brazilian study did measure tinnitus, but only in teenagers. Most of them had already experienced tinnitus, and a high percentage had chronic tinnitus.
So the studies measured different audiences for different purposes. There is no contradiction.
Dr. Debara Tucci, Professor of Otolaryngology at Duke University, initially expressed surprise at the JAMA study showing reduced hearing loss. (3) “But then I thought about all the reasons why hearing loss might be declining.” It is a long list, including the closing of noisy factories, reduced use of medications (like some antibiotics) that can cause hearing loss, immunizations to prevent childhood illnesses like measles that can affect hearing, and better health in general.
She noted that in her region most of the noisy textile factories, where many of her patients used to work, are now closed. “I used to see a huge amount of noise-induced hearing loss. I don’t see that so much anymore.”
The conclusion here is that older, working-age people are not experiencing the same degree of industrial and work-related noise as they had in the past, so the AMA survey shows less hearing impairment.
Consider my own experience. At 71 years old I fall slightly outside the study parameters, but my experience was common for my generation. When I left the US Army and its loud noises in 1967, I went to work in a copper refinery while starting college. The blast furnaces were so loud that I couldn’t hear my co-workers even if they were yelling at me. No doubt all this noise contributed to my hearing loss and tinnitus.
Even if there’s less noise at work for adults generally, which accounts for the AMA study’s results, young people who use headphones and earbuds risk losing their hearing and experiencing tinnitus, as the Brazilian study shows. They must be taught the danger of too much loud music – and that hearing loss is not reversible. Once they’ve lost their hearing, it’s gone.
Arches Tinnitus Formula
Those who experience hearing loss and tinnitus may find relief in the form of Arches Tinnitus Formula, with Ginkgo Max 26/7. Clinical studies have shown that ATF reduces tinnitus for the great majority of people who use it, especially those whose tinnitus is due to hearing loss.
(Insert ATF Graphic)
Manhattan Ear, Nose and Throat specialist Darius Kohan, MD, has separated his tinnitus patients into those who have it due to hearing loss and those who have it from other causes. He states, “Arches Tinnitus Formula doesn’t work with everybody, but it works with 75% to 80% of these patients (with hearing loss). Arches Tinnitus Formula is a safe and benign treatment that we initiate for patients.”
Remember: Silence is a Science®
1 – Hoffman HJ, Dobie RA, et al, “Declining Prevalence of Hearing Loss in US Adults Aged 20 to 69 Years. JAMA Otology Head Neck Surg. Doi:10.1001/jamaoto.2016.3527. Published online December 15, 2016
2 – Sanchez TG, Moraes F, et al, “Tinnitus is Associated with Reduced Sound Level Tolerance in Adolescents with Normal Audiograms and Otoacoustic Emissions.” Sci Rep. 2016: 6: 27109. Doi:10.1038/srep27109. Published online June 6, 2016.
3 – Gina Kolata, “Despite Headphones, Hearing Loss Declines.” New York Times December 16, 2016.