Can You Hear While Sleeping

Can You Hear While Sleeping?

In Sleep by Jack Felix, ACA, BC, HISLeave a Comment

Jack Felix, ACA, BC, HIS
Latest posts by Jack Felix, ACA, BC, HIS (see all)

Have you ever fallen asleep and felt like you’ve missed a lot. It is possible to fall asleep in the middle of all the actions and not be aware of any of it. However, just because you don’t consciously remember it doesn’t mean your brain isn’t registering the sound around you. After you fall asleep, your brain is more responsive than you might first suspect. Here is a brief exploration into how you hear while you slumber.

Sleep Stages

To understand your brain’s relationships with hearing while you sleep it is essential to first understand the stages of sleep. There are four sleep stages that occur through the night sometimes several times in one night. In fact, on a typical night, you will probably experience four to six sleep cycles.

  • Stage 1: This is the stage where you start to drift off into sleep. Your body is still in the process of relaxing and may twitch as you slowly transition into the next stage. It is also very easy to become roused awake during this first stage of sleep.
  • Stage 2: As you continue into deeper sleep, your heart rate, breathing, and temperature all begin to slow down. This is also true of your brain waves and it becomes more difficult to be roused by external sources.
  • Stage 3: By the third stage of sleep, you are settling into a deep sleep.  Your breathing and heart rate continues to drop. This third stage is essential for health, healing, and regeneration. In this stage, you also restore your immune system and consolidate memories.
  • Stage 4: In the fourth stage of sleep is when you enter REM sleep. REM stands for rapid eye movement. During REM sleep, your eyes move around rapidly in a range of directions, but don’t send any visual information to your brain. However, your brain becomes very active, similar to when you are awake. Your breath will speed up. This is also the stage where you dream the most vividly. REM is important to your health, as it stimulates the areas of the brain that aid with learning and increases the production of proteins in the body and brain. Within the first cycle of sleep, REM will last about 10 minutes but by the final stage of REM, it could last up to an hour.

Hearing While We Sleep

In the past Doctors believed that while you slept you didn’t collect sound from the outside world. However, now we know this to not be entirely true. Have you ever woken from a dream in which a sound from the real world has infiltrated your dream life? Another example of this occurs when we wake up from a loud sound. This informs us that there is a part of our brain which is still listening while we rest. This is also exemplified by the likelihood of a new parent to wake up to the sound of their child’s cry in the night or when someone says your name.

Hearing and Sleep

2019 study was published in the  Human Nature Behavior Journal explored how our brain responds and processes external sound information during sleep. The findings revealed that even during sleep our brain is paying attention to the sounds around us. In fact, the brain actually prioritizes some sounds over others based on their importance to us. The study used a model in which they alternated playing two separate tracks during a sleep study of many participants. One track had a voice saying actual sentences while the other track was gibberish which mimicked speech. Using EEG brain monitoring the researchers were able to determine that even while sleeping, the participants of the study were able to pay more attention to the track playing actual sentences. 

Can You Hear While You’re Sleeping?

The study was able to identify that our brains were most able to hear and respond to external sound during the first two stages of sleep. As we enter deep sleep and then REM our brains typically are less likely to pick up external stimuli. If you have a hearing loss it can be more difficult to pick up and prioritize sounds. Treating a hearing loss during the day can retrain your brain to be more responsive at night. To find out more, schedule a hearing test today.

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