Rebecca S. Dewey, a research Fellow in Neuroimaging writing for The Conversation, addresses noise exposure, “the main cause of preventable hearing loss worldwide.” She cites a recently published study in The Lancet that “revealed that living in a noisy city increases your risk of hearing damage by 64%.” Why do cities increase the risk so dramatically? Dewey points to obvious sources–work noise at a construction site or recreational noise at a nightclub–but adds that people “might be exposed to loud noises so constantly throughout the day that you don’t even realise they are there.” She also notes that many of us engage in “self-harm”–that is, exposing ourselves via mp3 players and mobile phones to damaging noise levels “with little more than a disclaimer from the manufacturers.”
Why is this a concern? Because of strides researchers have made about how hearing loss develops, aided by the relatively recent discovery of “hidden hearing loss.” Dewey states that it used to be believed that “noise-induced hearing loss resulted from damage to the sound-sensing cells in the cochlea,” but recent studies have shown that “even relatively moderate amounts of noise exposure can cause damage to the auditory nerve – the nerve connecting the inner ear to the brain.”
Unfortunately, the standard audiology exam “measures hearing by finding the quietest sound a person can hear in a quiet environment,” but hidden hearing loss affects “the ability to hear subtle changes in loud sounds,” what is called “supra-threshold.” Supra-threshold hearing is used to “understand conversations in a noisy room or hear someone talk over the sound of a blaring television.” In short, a traditional hearing test can’t detect hidden hearing loss, and attempts to measure it by playing a recording of speech masked with background noise “depends a lot on the ability of the patient to understand and cooperate with the test.”
Fortunately, Dewey works on a team at University of Nottingham that is developing an objective test using MRI scans that will “detect hidden hearing loss by scanning the parts of the hearing system that connect the ears to the brain.” The goal is to “understand who is most at risk and act early to prevent further hearing loss.”
And prevention is key, because there currently is no treatment or cure for hidden hearing loss. So do yourself a favor and avoid loud noise when you can, use earplugs when you cannot, and lower the volume on your personal audio devices. One day there will likely be a good treatment available for hearing loss, but no one knows if that day is five, ten, 20, or more years away. Why gamble on a future cure when prevention works today?