Greyscale questions

What is Greyscale?

Greyscale is a free Android app by Sonicon Software that plays noise and ambient sound mixes for three moments: falling asleep, settling a baby and focusing. It has 19 sounds, a mixer for up to five layers and a sleep timer that fades out. It has no ads, no account and no internet permission.

Does Greyscale work offline?

Yes. Greyscale doesn't request Android's internet permission, so it can't go online at all. All 19 sounds ship inside the app: the noise colours and steady sounds are generated on your phone, and the eight recorded sounds are bundled files. Nothing streams or downloads, and there is no account to sign in to.

Is Greyscale free?

Yes. Greyscale is a free download with no ads, no in-app purchases and no subscription. Every sound, mode and feature works without paying or signing up, and the mixes you save stay yours to edit, rename or delete. There is nothing to buy inside the app.

What's the difference between white, pink and brown noise?

White noise has the same energy at every frequency, so it sounds bright and hissy. Pink noise turns the high end down and sounds softer. Brown noise turns it down twice as steeply, into a deep rumble. Greyscale also has grey noise, shaped to sound even across pitches, brighter blue and violet, and green, centred on the mid range.

Does the sound loop?

The noise colours and the four steady sounds (fan, wind, ocean surf and womb) are generated live on your phone, so they have no loop. Each recorded sound switches between three recorded passages with 2 to 4 second crossfades at random points, and thunder and birdsong arrive at random moments, so there is no fixed loop point.

Over a long night the same passages come back; no 30-second stretch repeats exactly within 10 minutes. See Inputs and limits.

How does the sleep timer end?

It fades out instead of cutting off. You set the fade-out in Settings, from 30 seconds to 10 minutes; Sleep and Baby start at 2 minutes. Sleep suggests a 45-minute timer, and the notification's Timer button steps through 15, 30, 45, 60 and 90 minutes. Cancel during the fade and the sound comes back up.

What does Baby mode do?

Baby mode starts at a low volume, 40% of Greyscale's own maximum, with a volume cap on Greyscale's sound that is on at 50% by default. It shows a placement tip once, offers a fade-off timer of 30, 60 or 120 minutes, and its mixes leave out thunder and forest birds, the two sounds with sudden noises.

Does Greyscale measure how loud it is in the room?

No. Greyscale has no microphone permission and doesn't measure sound levels. Its volume cap limits only Greyscale's own output, not your phone's volume or a connected speaker, so how loud it is in the room depends on your phone, speaker and settings. The Baby tip suggests placing the phone about 2 metres from the cot and keeping the volume low.

Can Greyscale play alongside music or a podcast?

Yes, in Focus mode. Focus has Mix with other audio on by default, so Greyscale keeps playing under your music or podcast. Optional focus sessions run work and break rounds, 25 and 5 minutes for 4 rounds to start. During a break the sound dips to 30%, and a soft chime, which you can turn off, marks each change.

Why did the sound stop during the night?

Some phones stop apps in the background to save battery, even while they play sound. Greyscale keeps playing with the screen off as a media playback service, and its Battery help shows the settings steps for your phone's brand. A phone call, unplugging headphones or the end of a timer also pauses or stops the sound.

Greyscale doesn't ask to be exempted from battery optimisation. Battery help can open Android's own settings screens; the change is yours to make.

Can I start Greyscale without opening the app?

Yes. The Quick Settings tile turns your last mix on or off. The home-screen widget has Play and Stop plus Sleep, Baby and Focus buttons. On the lock screen, the notification has Play and Pause, a Timer button and Next mix. Headset and Bluetooth media buttons work once a mix has played.

Does Greyscale collect any data?

No. Greyscale has no account, ads or analytics and no internet permission, so it can't send anything to us or anyone else. Your saved mixes and settings stay in the app's storage on your phone, and Android's own backup can copy them to your Google account or a new phone. The privacy policy has the details.