What do you fall asleep to?
Maybe it’s the whirring of a fan, your favorite audio book, or reruns of TV playing in the background. Everyone has their go-to sleep environment, some of us need total silence, but for many, Sound is indeed the secret to winding down.
While these habits might seem like bedtime quirks, research shows that certain frequencies of sound can do more than soothe. They can actually help regulate the nervous system and promote deeper, more restful sleep. From your roommate's noise machine that they swear by, to the sound of rain on the sidewalk, what we listen to can have a meaningful impact on how we feel.
But it’s not just about sleep. Sound plays a critical role in our waking hours too. Certain sounds can help manage anxiety, improve focus, and support emotional regulation. I’ve seen firsthand how integrating background noise or intentional sound into daily routines can bring a sense of calm and control into people’s daily lives.
So, let’s talk about how it works, and why some types of sound have different effects than others.
What’s with the “Colors” of Noise?
People often say, “white noise,” while referring to any kind of background hum. But technically, white noise is just one type, and there are many more with different sonic and neurological properties:
White noise includes all audible frequencies at equal intensity. It sounds like static or a fan and is great for blocking out environmental distractions. (Stanchina et al., 2005)
Pink noise, however, gives more emphasis to lower frequencies. It sounds like steady rain or waves and has been associated with improved deep sleep as well as memory consolidation (Zhou et al., 2012).
Brown noise is even deeper, with stronger low-frequency energy. It is often described as a low rumble or thunder-like sound, and many individuals with ADHD claim it helps them feel more grounded and focused (Jostrup, 2025).
Green noise typically refers to natural sounds like forests, waterfalls, and gentle ocean waves. This essentially blends aspects of pink and brown noise into a soothing, nature-like soundscape (Alvarsson et al., 2010).
Selecting the right type of noise can act like a switch for your nervous system, helping your body feel more regulated and less reactive.
Why Sound Calms the Brain
Here’s a little psychology lesson: our brains are built to scan for active threats, even in rest. This hyper-vigilance, while evolutionarily useful and effective, is a poor match for sleep and relaxation in our modern, and quite frankly, noisy, world.
When you sleep in a silent room, every small noise like a door creak, a distant elevator ding, or thunder in the distance can trigger your brain’s alarm system. These noises act as micro-arousals, briefly increasing alertness and disrupting the body’s ability to fully rest. Steady background noise, on the other hand, helps signal to the brain that the environment is stable and predictable. In response, the nervous system remains calm and stops scanning for threat (Goldman & Goldman, 2021).
Creating a Calm Bedtime Routine
If you’ve ever used a white noise machine or an ambient sleep playlist, you’ve already experienced the power of sound for sleep. For individuals experiencing insomnia, whether from anxiety, trauma, or racing thoughts, sound becomes more than a background feature. It acts as a signal to the brain, transitioning the body into rest mode.
Zhou et al. (2012) even found that pink noise not only helped participants fall asleep faster, but also improved the quality of their sleep. Similarly, nature-based sounds, or green noise, has been shown to reduce cortisol levels and heart rate, activating the parasympathetic nervous system, your body’s own “rest and digest” state (Alvarsson et al., 2010).
Many have found success with using sound intentionally to build nighttime rituals. They choose 30-minute ambient tracks, set timers, and use the repetition to train their brains to associate these sounds with winding down. Over time, the ritual becomes just as soothing as the noise itself.
Using Sound to Support Focus
When we think of sound we often think of its ability to disrupt focus. We study in quiet libraries, avoid noisy cafes when we need to concentrate, and associate silence with productivity. But the relationship between sound and focus is more complex than it seems.
Many individuals with Attention Deficit Hyperactivity Disorder (ADHD) or sensory sensitivity often experience silence not as calm but as a trigger for overstimulation. Without background input, there is much more room for internal distractions to take over. Racing thoughts, restlessness, physical discomfort to name a few.
Incorporating sound can act like a buffer, a steady anchor that grounds the brain in the present and reduces mental clutter. By ‘busying’ the auditory system, sound helps quiet the noise inside, securing attention and reducing the noise of internal stimuli.
Background noise gives the brain something predictable to focus on. It reduces the mental “chatter” and helps improve what neuroscientists call sensory gating: the brain’s ability to filter out distractions (Blomberg, 2022)
Research backs this up. One study found that white noise helped children with ADHD concentrate and retain information by stabilizing dopamine release, which is often dysregulated in ADHD (Sikström & Söderlund, 2007). Structured sensory input, such as background noise, tends to reduce inattentive behaviors while improving cognitive performance- a win win!
Sound as a Self-Regulation Tool
From a clinical lens, I see sound as a simple yet powerful tool in the broader toolkit of nervous system regulation. Sound is one of the most accessible and non-invasive tools we can use to regulate the nervous system. It doesn’t require a diagnosis, a prescription, or any sort of special equipment. Just curiosity and attention.
I often encourage clients to play around with different sound frequencies and notice what feels helpful. Try brown noise during when you need to get into a flow state, or pink noise as part of your bedtime wind-down routine. Pay attention to how your body responds. Do certain sounds bring a sense of calm, focus, or comfort? Could you use that awareness to build a personalized plan that supports your daily rhythms? There’s no one-size-fits-all.
Ultimately, the best tool is the one that works for you.
Tuning In: What Your Nervous System Might Need to Hear
Sound is more than background noise; it’s a form of regulation. A way to signal safety, create structure, and support your emotional and physiological well-being. Whether it be the low hum of a fan, nature sounds in your headphones, or a playlist that allows you to turn inward, it’s evident that sound has the power to shift how we feel in our daily lives.
So, if you’ve been feeling anxious, unfocused, or unable to truly unwind and rest, it might be worth asking: What does my nervous system need to hear?
References:
Alvarsson, J. J., Wiens, S., & Nilsson, M. E. (2010). Stress recovery during exposure to nature sound and environmental noise. International journal of environmental research and public health, 7(3), 1036-1046.
Blomberg, R. (2022). Auditory Distraction in ADHD from Behaviour to the Brain. Linkopings Universitet (Sweden).
Goldman, J., & Goldman, A. (2021). The Humming Effect: Sound Healing for Health and Happiness. Healing Arts Press.
Jostrup, E. (2025). Sensory noise as a possible non-pharmacological intervention for children with attention-deficit/hyperactivity disorder (Doctoral dissertation, Lund University).
Sikström, S., & Söderlund, G. (2007). Stimulus-dependent dopamine release in attention-deficit/hyperactivity disorder. Behavioral and Brain Functions.
Stanchina, M. L., Abu-Hijleh, M., Chaudhry, B. K., Carlisle, C. C., & Millman, R. P. (2005). The influence of white noise on sleep in subjects exposed to ICU noise. Sleep Medicine, 6(5), 423–428.
Zhou, J., Liu, D., Li, X., Ma, J., Zhang, J., & Fang, J. (2012). Pink noise: effect on complexity synchronization of brain activity and sleep consolidation. Jor. of Theoretical Biology.