The Surprising Sleep Sound That Can Improve Sleep Quality (Nope, Not White Noise)

Bedtime stories hold a special place in many people's hearts, and for good reason. Aside from the sentimental value they carry, recent research suggests that bedtime stories might have benefits for adults as well.

The study, published in the Journal of Sleep Research, found that when relaxing words were played during non-rapid-eye-movement sleep (NREM), there was an increase in deep sleep duration and subjective sleep quality. 

To reach these conclusions, they tested how word presentation affected ECG (heartbeat) activity during NREM sleep. They observed that the time between heartbeats was longer during the presentation of relaxing words compared to control words, indicating a slowdown of cardiac activity specific to the relaxing words when compared to control words. 

They also found that cardiac activity carries information about sleep depth and modulation, independent of brain activity, supporting the importance of considering bodily signals when analyzing sleep functions. 

Most of the time, research around sleep focuses solely on the brain, not the full body. However, this study shows that even while you're clocking some shut-eye, your body does pick up sounds in the space around you—impacting both your heart rate and sleep quality. 

All the stages of sleep work together to help you restore your body and mind and wake up feeling rested.

Deep sleep (also sometimes called slow-wave sleep) is the third stage of sleep, following two stages of light sleep. About 20% to 25% of our time asleep is spent in this stage, during which muscle and tissue growth are promoted, as well as cellular repair.

In other words, if you don't get enough deep sleep, you don't give your body a chance to properly recover from the day. So if you think you're lacking in deep sleep (or your wearable sleep tracker tells you so), it's worth investing some time into optimizing your sleep environment and maybe even testing out some relaxing words. 

You can search soothing words on YouTube or get a sound machine with some prerecorded sleep stories. Whatever you choose, be sure to let it play throughout the night (at a low volume of course) for optimal benefits. 

You'd also be wise to elevate other elements of your wind-down routine while you're at it. A few ways to do so include keeping your space cool (generally between 60 and 68 degrees Fahrenheit), investing in high-quality sheets you love, and considering melatonin-free sleep supplements. 

Now, if you've tried it all and have been met with little to no sleep improvements, pay a visit to your health care provider for a more tailored game plan.