Tinnitus is a condition affecting 250 million people globally. Tinnitus can be caused by intense exposure to sound, hearing loss, or damage to the ear. Individuals with tinnitus most commonly have damage to the hair cells or fibres of the auditory nerve. The phantom perception of tinnitus is often accompanied by hyperactivity in the auditory system and parts of the brain involved in hearing.

Sleep and Tinnitus

A recent study found that 54% of people with tinnitus also have a sleep disorder. This relationship between tinnitus and sleep is due to the interaction between the sleep-wake cycle and tinnitus. During sleep, the brain goes through multiple stages, with about 75% of the total sleep time spent in non-rapid eye movement (NREM) sleep. This stage is the most restful and critical for the recovery of neurons in the brain. 

In people with tinnitus, the brain regions impacted by tinnitus show slow-wave activity during NREM sleep meaning some people with tinnitus have disturbed sleep and night terrors, as the hyperactive brain regions do not enter deep sleep, leading to more time spent in light sleep. The hyperactivity can be explained by the overcompensation of the central auditory system as a result of the damage in the auditory nervous system.

Suppressing Tinnitus

In some cases, people with tinnitus did not have their sleep affected as the brain activity during deep sleep suppressed the tinnitus. The first way that tinnitus can be suppressed during sleep has to do with neurons. With a long period of wakefulness, neurons will switch to slow-wave sleep to recover. As a result, the more neurons in the slow-wave sleep cycle, the more likely it is that other neurons will join in this process. With the rest of the neurons joining in this process, parts of the brain that would normally be awake due to tinnitus are instead performing slow-wave activity.

The suppression of tinnitus during deep sleep (NREM) is due to the slow-wave activity interfering with communication between brain areas, resulting in the hyperactive regions of the brain not being able to disrupt other areas of the brain. It is also important to know what activity or action aggravates your own tinnitus so you can better manage your hearing health during the day, and night.

Treating Tinnitus and Better Sleep

Discoveries on the correlation between sleep and tinnitus will continue with more research on how tinnitus changes during each sleep stage. This could further the understanding of why tinnitus changes in intensity. Future treatments for tinnitus could include manipulating sleep. Some professionals suggest that having patients go to bed when tired could boost the intensity of sleep.

Some people with tinnitus would benefit from better sleep and from creating a healthy sleep-friendly environment. This can include tinnitus sound therapy such as SoundRelief by Lios. Sticking to a sleep schedule is also very important, as a consistent sleep schedule helps the brain know when to shut off. Caffeine can often be a trigger for people with tinnitus, so limiting caffeine, especially after lunchtime is important. Lastly, turning off electronic devices can help people with tinnitus to sleep better. Electronic devices emit blue light which mimics daylight and reduces the production of melatonin, a hormone produced by the body which is needed to fall asleep.

With the ongoing study of the link between sleep and tinnitus, there are many more discoveries to come. As researchers dive deeper into the different sleep cycles and how each stage reveals more about tinnitus, there is hope for future treatments.