How Older Adults Hear
Many people will experience hearing loss as they get older. The hearing of the typical 40 year old is already slightly poorer than that of the typical 18 year old.
Presbycusis - the loss of hearing due to aging - is one of the most common causes of sensorineural hearing loss. The typical pattern is a loss of sensitivity for the high-frequency sounds that are important for the clarity of speech (”I can hear but I can’t understand”). But recent research suggests that we may also experience a reduction in our ability to process complex auditory signals as we get older.
The result may be only a mildly reduced ability to understand speech in easy listening conditions, but significantly more difficulty in noisy conditions. This increased difficulty may be present even in older adults with normal hearing sensitivity.
The central auditory system
Although it is our ears that hear the sounds around us, it is our central auditory system - the hearing nerve and the brain - that allow us to understand that pattern of sound. Researchers have found evidence of age-related changes in the central auditory system that is independent of any loss of hearing sensitivity. These changes include a reduction in the number of hearing nerve cells and a reduction in the speed at which the nerves transmit signals. In other words, it’s not only the ears - it’s also the brain.
As a result, older adults may have greater difficulty with complex auditory tasks when compared to younger individuals with similar hearing sensitivity. An older adult may complain of having difficulty to noisy conditions or in groups of people, even if that adult has normal hearing.
As we follow someone’s hearing over 10 to 15 years, it is not unusual for that person to complain of increased difficulties in noisy situations even when hearing thresholds and ability to understand speech in quiet are relatively unchanged.
The role of hearing aids
The effects of aging on hearing go beyond a simple loss of hearing sensitivity. These changes may be minimized by using hearing aids to stimulate the auditory system (as well as to provide better hearing). Other “communication strategies,” such as lip-reading and avoiding noisy restaurants, are also helpful. But as helpful as hearing aids are, remember that hearing aids do not correct or cure these changes to the central auditory system.
Hearing loss is one of the most common chronic health conditions and has important implications for a person’s quality of life. However, hearing loss is substantially undetected and untreated. Only 10% of primary care physicians screen their adult patients for hearing loss. Consult a licensed audiologist for regular comprehensive exams.
Deborah Touchette, Au.D. - Doctor of Audiology