Sound Machines Aren’t Just for Sleep. Here’s How to Use Brown Noise to Focus at Work.

The LectroFan EVO is a compact option with a small footprint best suited for tighter spaces. All of its control buttons are on the sloped top of the machine, making it easily accessible even if it’s shoved in the back corner of your desk. A favorite for its rich and clear sounds, the LectroFan EVO can generate 10 colored sounds ranging from a low-frequency brown noise to a high-frequency white noise. These noises sound like variations of low rumbles, rushing wind, or static. Press the button with the sound-wave icon to cycle through the options; brown noise is the first click.

The EVO can also connect to speakers to amplify the sound, or to headphones if you concentrate better when sound is localized. Once turned on, the EVO will play until it’s turned off, but you’re also able to set a timer with 60-minute increments up to eight hours. This is helpful if you like to work in intervals.

The Sound+Sleep has a range of white noise variations that are easy to select from, thanks to this machine’s well-labeled dial; simply spin the dial to brown noise. The Sound+Sleep also has a large variety of real-world sounds, like the rush of a waterfall, the crackle of a fire, and the rumble of a train. Not only does the machine have nine ambient noises, but it also allows you to enhance each of its sounds with the richness button, which layers in additional recordings to create a more complex soundscape. For instance, if you choose the wind blowing through a meadow, you can add in the sound of chirping birds or crickets. This sound machine is pricier than our top pick but can be a worthwhile splurge for folks who find that any kind of ambient sound helps them focus.

Like the LectroFan EVO, this sound machine can connect to speakers and headphones, and it also has a timer that can be set in 30-minute increments.

If you’re around others in a noisy office but need to focus, the free myNoise app can come in handy. Available in the App Store and on Google Play, this app offers a range of white noise and natural sounds, and the intensity of the various frequencies can be customized to suit your preferences and surroundings.

To access brown noise specifically, select White Noise & Co. The app’s display will show you a rainbow of adjustable columns corresponding to different frequencies; tap Default just below to open the preset menu. Navigate to Color then select Brown. It also allows you to set a timer to the minute, something the above sound machines we recommend don’t have. The free version of myNoise offers a decent range of sounds, and the full acoustic library is available for about $10.

YouTube and Spotify also have a trove of free brown noise content. On YouTube, you can easily find eight-, 10-, and 12-hour brown noise videos, and on Spotify, curated playlists dedicated to the soothing noise abound. Though these options are free, we still prefer the free version of myNoise: Many Spotify and YouTube options have ads throughout the stream, which can be jarring and distracting, and some are actually a series of much shorter sounds spliced together, unlike the immersive sounds on myNoise.

Ultimately, the audio quality of your sounds app (or the Spotify playlist of your choice) depends on the quality of your headphones. The 1More SonoFlow are budget-friendly noise-cancelling headphones that sound good and are comfortable to wear for extended periods. The lightweight design doesn’t pinch or press down on your head, and the squishy earpads feel like memory foam.

When you’re using your sound generator—no matter what you’re using it for—there are a few tiny things to keep in mind to protect your hearing and ensure your machine is working as effectively as possible.

Adjust the volume. If your white noise machine lives on your nightstand, it’s worth checking the decibel level with a free dB monitoring app to ensure you don’t hurt your ears. To protect your hearing, the decibel level should be no higher than the mid-50s but preferably in the 40s, as the Centers for Disease Control and Prevention categorizes this range as the upper level of what is safe and not likely to cause hearing damage. Wirecutter audio expert Lauren Dragan recommends using the NIOSH Sound Level Meter app (available for both iOS and Android) or Apple Watch’s built-in dB reader.

Place your sound generator between you and the source of the noise. Your sound machine will be most effective if it can act as a barrier to annoying sounds. If noisy traffic keeps you up at night, stick your white noise machine between your bed and the window, but if your kids are the ones making a racket while you’re trying to work, you should place your machine between you and the door.

Don’t place your machine anywhere it can be obstructed. You won’t be able to hear the ambient noise if you place it under your bed or behind thick curtains. We also recommend keeping it off the floor beside your bed—you wouldn’t want your blanket to accidentally fall on top of it in the middle of the night.

This article was edited by Alex Aciman and Catherine Kast.