The sky is blue. The sun rises in the east. My bull terriers think they’re lap dogs. These are undeniable universal truths that cannot be disputed.
Here’s another: repeated exposure to loud music causes hearing loss. We should limit our exposure. We’re supposed to wear hearing protection. Turn down the earbuds and headphones. Watch the volume on the stereo. Our hearing is going to degrade as we get older, anyway, so we’d better protect what we have.
But hang on. Not so fast. Is it possible we have that all wrong?
Over at the University of Texas at Dallas, Dr. Colleen Le Prell, a professor of hearing science, has been studying the causal relationship between “recreational noise exposure” and “auditory functions” in people. In a shocking discovery, Dr. Le Prell couldn’t find evidence of auditory nerve damage or any permanent hearing loss among young people who attended “loud events” like music festivals and dance clubs.
All the participants went to various music events with a smartphone app that recorded sound pressure levels. Their hearing was tested afterwards. The result? “For the typical young person going to common recreational events, [research] suggests that they’re not the primary group that’s going to be at risk for damage.”
Given the worrying implications of hidden hearing loss caused by recreational noise, Le Prell and her team assessed neural function and hearing performance in young adults before and after attending a loud recreational event. Different people attended different types of events, which included a concert, a multi-day music festival, a bar with live or electronic music, and a movie. The team also looked for any relationship between the participants’ history of noise exposure in the previous 12 months and their baseline “before” assessments.
The study, published in open-access journal Frontiers in Neuroscience, is the first to prospectively monitor potential hearing change: Previous studies have only examined this retrospectively based on self-reported noise exposure history. In another first, the participants used a smartphone app to measure the sound level during the recreational event. The tests included assessments of middle ear, cochlear and auditory nerve function, determination of the hearing threshold level, and a Words-in-Noise test to evaluate how well the participants could understand speech in background noise.
The team did not find any statistically significant relationship between retrospective recreational noise history and neural function. While a temporary threshold shift was observed within 24 hours of attending the recreational event, the effect was generally small and had disappeared one week later. Similarly, while Words-in-Noise performance was lower one day after the event, there was no significant effect one week later. There was also no evidence of neural injury following the recreational event, either within 24 hours of the event or one week later.
“Despite multiple calls for alarm in the media and in the scientific literature, we found no evidence that typical recreational noise exposure is associated with permanent decreased auditory nerve function or poorer understanding of speech when there is background noise,” says Dr Le Prell.
This does not mean that all recreational loud noise is safe, however. Other studies suggest that firearm users, for example, are almost certainly likely to be at risk for neural injuries.
Fascinating. Still, I’m going to maintain my healthy paranoia of hearing loss. Just in case, you know?
The whole study can be found here.