Sleep Mask: Adaptive Noise

COOL-S

About this app

Most sleep sound apps just loop a recording. Sleep Mask is different: it listens to your room and continuously reshapes its noise to cover the specific sounds that keep you awake, like a snoring partner, traffic, a TV in the next room, or hallway voices.

ADAPTIVE MASKING, NOT A LOOP Sleep Mask synthesizes noise in real time and samples your room's sound several times a second. It analyzes what it hears across 24 perceptual frequency bands and automatically lifts the noise exactly where intruding sounds live, with no manual EQ and no guessing. As the room changes, the sound follows.

TWO WAYS TO MASK • Level mode covers everything, matching the loudness of detected sound in each band, for when you want a steady wall of sound. • Flux mode targets only changing sounds like snores, voices, or a passing car, while ignoring steady hum like a fan or AC. Quieter overall, and great for light sleepers.

PICK YOUR SOUND Choose from six noise colors: White, Pink, Warm Pink, Brown, Deep Brown, and Fan. Then shape the highs with Open, Soft, Warm, or Dark tone presets. From bright and airy to deep and rumbly, dial in the texture you actually like to fall asleep to.

SEE IT WORK A live spectrum view shows three traces at a glance: what your room sounds like, what the app is playing, and the adaptive correction it's applying. Watch it respond the moment a sound appears.

TUNE IT TO YOU • Adaptation speed (Fast, Medium, or Slow) sets how quickly the sound reacts. • Max boost caps how much louder it's allowed to push, so it never gets jarring. • A master volume and output picker let you send sound to the phone speaker, Bluetooth earbuds, or wired headphones.

SLEEP TIMER Set a stop time and Sleep Mask fades out on its own, with a live countdown so you always know when it ends.

PRIVATE BY DESIGN The microphone is used only to listen to your room so the noise can adapt. Audio is analyzed entirely on your device in real time, and nothing is ever recorded, saved, or sent anywhere. Sleep Mask has no internet permission at all: no accounts, no ads, no tracking, no data collection. What happens in your bedroom stays on your phone.

NO MONTHLY FEE No subscription and no monthly fee. Every feature is included, with nothing locked behind a paywall.

BUILT FOR SLEEP • Real-time adaptive noise masking • Level and Flux masking modes • 6 noise colors plus 4 tone presets • Live spectrum visualization • Adjustable adaptation speed and max boost • Sleep timer with countdown • Bluetooth, wired, and speaker output • Fully offline, with no ads, no accounts, and no tracking • No subscription, no monthly fee

Whether it's a partner who snores, a noisy street, thin apartment walls, or a restless mind that needs something to hold onto, Sleep Mask gives you a sound that actively works to keep the room quiet, so you can fall asleep and stay asleep.

What’s new

White, pink & brown noise that adapts in real time to mask the sounds around you.