Headphones, earplugs and central gain theory: a honey-trap for sound intolerance

These days everyone uses headphones and earplugs can be easily purchased. It is sensible to protect our hearing from loud noise: noise exposure is one of the most common cause of hearing loss. Protecting your hearing can prevent certain types of hearing loss and because damage to the hearing can lead to Tinnitus, it also reduces the risk of developing Tinnitus.

But what happens if you overuse ear protection? How would it affect your hearing if you were to use earplugs all the time? The answer to that question is: you become more sensitive to the loudness of sounds. Surprising? Maybe but it well explained in central gain (or another name for it is auditory gain) theory. Central gain theory says that when there is not enough external input (external noise) the auditory cortex tries to compensate and turn on the sensitivity by lowering the threshold of loudness. In practice, everyday sounds will seem louder.

This theory was put to test in experiments: people with normal hearing were asked to wear earplugs for 2 weeks and then they were tested what level of loudness they would find uncomfortable. The outcome was that all participants became more sensitive and less tolerant of the loudness. After this first phase, the researchers fitted the participants with sound devices for another 2 weeks. This time the participants were listening to sounds constantly. When the 2 weeks were up, participants were retested: and this time they were less perceptive of the loudness. Conclusion: the lack of sounds result in hypersensitive hearing. It also shows neuroplasticity : how our brain tries to compensate for the “missing” information.

What does this mean for people who have sound intolerance? It is understandable that if you find certain sounds too loud, you would try to avoid them: nosy people, crowded places, cinemas, theatres, hissing fans, loud waterpipes etc. People who have Hyperacusis or Misophonia find everyday sounds triggering, this could be the sound level of a normal conversation, someone tapping their foot or clicking a pen, to the noise of breathing, chewing, yawning. If the sound is triggering intense emotions such as frustration, disgust or even fear, it seems sensible to mask them by wearing headphones or earplugs.

However, this can unintentionally make symptoms worse because of central gain, the overcompensation and increasing sensitivity. So if you rely on earplugs to get through your day, you will find it harder and harder not to use it.

What can you do to avoid this effect? If you find yourself being overly reliant on earplugs and headphones, you can try gradually reduce how long you have them on. How to do this: don’t go all-in first time, it is better if you choose situations that you find relatively easy and not too distressing. Take this as an experiment: ask yourself to take it off for a while (you can set a timer) and see what happens. If you find you can tolerate it better than imagined, then increase the time when you don’t use these devices.

If it was indeed too much to handle, then think about what would be an easier first step, a different situation or shorter time. Don’t put too much pressure on yourself to get it right: it is an experiment. You can gradually expand your window of tolerance.

In CBT for Hyperacusis and Misophonia we do something similar: we create a variety of behavioural experiments to increase your tolerance toward trigger sounds. This is a very important step to gain more confidence and start the journey toward habituation (when you get used to the sound and can ignore it most of the time).

Headphones and earplugs can be beneficial to protect your hearing from noise exposure, they can play a role in making life easier for those who experience sound intolerance. However, using it too often can backfire and increase sensitivity to loudness. All in all, finding the right balance for you is the most important.