“Fifty percent of adults older than 60 have a clinically meaningful hearing loss, which increases to every two out of three adults older than 70,” Jennifer A. Deal, PhD, explains. “Hearing loss impacts everyday communication and QOL, but there is growing evidence that it is also an important risk factor for dementia and cognitive decline. Although we know how to treat hearing loss, except for taking precautions against noise exposure, we really don’t know how to prevent hearing loss from occurring in the first place.”

For a study published in JAMA Otolaryngology–Head & Neck Surgery, Dr. Deal and colleagues sought to examine the association of cigarette smoking patterns with audiometric and speech-in-noise hearing measures. The cross-sectional study involved participants in the Atherosclerosis Risk in Communities Study and included data from visits one (1987-1989) through six (2016-2017). Smoking behavior was categorized from visit one to visit six via self-reported smoking status at each visit and hearing was evaluated at visit six.

“We also used advanced methodology to account for the fact that current smoking is associated with dropping out of a study over time,” Dr. Deal notes. “Failure to account for this bias can lead to an underestimation of the association between smoking and hearing over time. No prior studies had done this.”

Smoking Cessation Has Benefits for Hearing Health

The study included 3,414 participants aged 72 to 94, more than half (59.5%) of whom were women. Researchers used three smoking categories: never or former smoking at baseline (N=2,911; 85.3%), quit smoking during the study (N=368; 10.8%), and persistent smoking (N=135; 4.0%). According to Dr. Deal, previous research demonstrates that smoking cessation is beneficial for heart health, and the current study showed that it benefits hearing health, too.

“We had two measures of hearing—pure tone audiometry to measure what’s happening in the inner ear and speech-in-noise, which measures central auditory processing,” explains Dr. Deal. “For both measures, we found that the risk for hearing loss for participants who quit smoking was essentially equivalent to the risk in never-smokers. Quitting smoking has benefits for hearing that is occurring in the ear, but also for hearing processing in the brain.”

The researchers also examined the frequencies that are important for speech, Dr. Deal notes. “Investigations of associations between smoking and hearing in low and high frequencies showed consistent results,” she explains. “Persistent smoking was associated with worse hearing, but there was no association for those who quit smoking during the study period (Table).”

Both Smoking & Noise Exposure Increase Risk for Hearing Loss

The researchers did acknowledge several limitations of their study, including the fact that hearing was only evaluated at one time point. As a result, they could not analyze the association of smoking patterns with the onset of hearing impairment over time. In addition, because the median age at study baseline was 51, it was likely that some older adults had existing hearing loss at that time.

“There is also some evidence in occupational cohorts that risk for hearing loss is increased in those who have a history of both smoking and noise exposure,” Dr. Deal notes, pointing to another avenue for future research.

The findings of this study support the use of smoking cessation as a possible strategy for reducing the risk for hearing impairment among older adults, according to the researchers. “We counsel patients on smoking cessation because it has so many health benefits,” says Dr. Deal. “Hearing health may also benefit. It would be great to have a study in which hearing is measured before and after a smoking cessation intervention.”