What is brown noise?

Brown noise is a deep, low, rumbling sound, a little like steady rainfall or a distant waterfall, with far more of its energy in the low frequencies than white noise. Many people find it soothing for focus, reading or drifting off to sleep, because the harsher high frequencies are rolled away.

Brown noise is one of three common colours of noise. Here is what each one is and how it sounds.

White, pink and brown noise, in plain terms

• White noise has every frequency at equal strength. It sounds bright and full, a bit like radio static or a fan on a high setting, and it masks sudden sounds well.
• Pink noise softens the higher frequencies, so it feels more balanced and natural, closer to steady rain or wind in the trees. Many people find it gentler than white noise.
• Brown noise, also called red noise, rolls the highs away further still, leaving a deep, low rumble. It is the warmest and heaviest of the three.

None of these has a single pitch. They are broadband, meaning they carry a whole spread of frequencies at once, which is why you cannot tune noise to a musical note.

Where 432 Hz fits in

432 Hz is a tuning, the idea of setting the musical note A to 432 rather than the usual 440. It is a single tone rather than a colour of noise, and some people simply enjoy the sound of it sitting quietly under the rumble. It is offered as a pleasant option, with no claims made about health or brainwaves.

Frequently asked questions

What is the difference between brown, pink and white noise?

They differ in how the sound energy is spread across frequencies. White is even across the board and sounds bright, pink softens the highs and sounds balanced, and brown rolls the highs away further for a deep, low rumble.

Is brown noise good for sleep or focus?

Many people find the steady, low sound helpful for concentrating or settling at night, mostly because it masks sudden noises. Everyone is different, so it is worth trying each colour to see which suits you. We make no medical claims for it.

Can I play brown noise free online?

Yes. The Kalm 432 Hz player generates brown, pink and white noise live in your browser, so there is nothing to download and nothing is uploaded.

Who makes Kalmtools

Kalmtools is built by Outside of the Fox, a design and learning studio in Stockport. We take the confusing, the half-built and the not-yet-existing and turn it into websites, e-learning, accessibility audits and digital products that work. If you have a project that needs that kind of care, come and say hello.