Breath rate detection & blood oxygen measurement

Sleep duration is the sum of all your sleep stages (light, REM, and deep), not including waking stages - because you are not really sleeping when you are awake.
So on default settings, your Sleep Duration ,ay be a little shorter than your tracking time.

If you want your sleep duration to be the same as your tracking duration:

Smart Bluetooth allows us to collect HR data from a non-compatible wearables, or oximeters.

If nothing helps please send us a debug report using Left ☰ menu → Support → Report a bug..

We use a different input than polysomnographists, and define our own sleep phases, reflecting an objective aspect of sleep, easy to measure with common devices. One naturally needs to ask whether there is any relationship between the EEG-phases and our ACT-phases.

Fortunately, several research teams raised similar questions before (See this one, or this one, or this one, or this one). They measured a bunch of people on a traditional polysomnograph and recorded their physical activity at the same time (By filming them and then counting the movements manually, or by using accelerometer readings). The published analyses show that there indeed is a significant statistical relationship between EEG-phases and body movements.

You can also read about comparison of Sleep as Android algorithms and Sleep lab results on our blog here.

Battery saving mode currently resumes full tracking before the Smart Wakeup period to find the best time for you to wake up so that tracking uses only a fraction of the battery consumption for the entire night. When the battery drops below your defined standby threshold (default: 10%), the battery saver mode will resume.

Accelerometers are really sensitive, which is great for sleep tracking. Usually what you see when you leave the phone on the table is immediately dwarfed when you make a more significant movement. Just leave the phone on the table for a while and you will see a dramatic spike, but then move the phone and you will see that all the development is really tiny compared to the new peak.

So what you see is random noise caused by very small vibrations of the table or in very quiet areas by seismic movement. We mark the data relatively, so you can always distinguish between light and deep sleep. However, the algorithm works well only in conditions, it assumes i.e. in the bed with relatively large movement peaks.
To be more precise, if you leave the phone on a table, you may get values perhaps in the range of 0.000001 to 0.000009 m/s2 (the value is made up here, but it is physically very small). In the bed, you can get values from 1 to 9 m/s2 (which is physically large). However, the algorithm only sees that the high value is 9 times higher than the low value in both cases.
We had to do this because each accelerometer (in different phones) measures differently, so we couldn’t assume a standard conversion formula that responds to absolute values.

So if you use the phone in bed, it is indeed drastically different from measuring in a quiet place, like the table.

Please do not hesitate to contact support@urbandroid.org for clarification. You can also read more about how our data compares to sleep lab results at in this post.

This depends on several factors. The general rule is to not allow the pet to move your phone, ideally only your movements should move the device. So in this case it’s best to place Your device either under the pillow or to have an armband or smartwatch/smartband. If your pet is a calm one, it may just work. However, if your pet is used to jump in and out of bed several times a night, the sleep tracking will most probably register these events as light sleep occurrences.

Ultrasound is generally considered safe if it is at normal volume. Regarding health effects, it works in a similar way to normal audible sound, i.e. very loud ultrasound can damage your hearing, whereas at low volume it is safe to hear. When using speakers, smartphones are nowhere close to be able to produce such loud sounds as to damage your hearing.
We also use ultrasound that is very close to the hearing range (around 20 kHz), so the effects of the ultrasound are almost identical to hearing a high pitched sound at the same volume (expect you can’t hear it at all).
The ultrasound volume we use is around 40 dB – which is lower than normal speech volume. You can measure the sound level yourself using e.g. this app.

For pets that are able to hear it, the ultrasound emitted from Sleep as Android is a constant low noise. The situation is similar to e.g. refrigerator noise. It is there, you can hear it, but it’s not so much disturbing. The ultrasound definitely cannot damage your pets hearing at the volume used in Sleep as Android.
Bats can be confused and fly into walls.

The only difference between normal audible sound and our sonar is that the frequency is a little higher (normal frequencies 2 Hz-20 kHz, our sonar frequencies 18 kHz-22 kHz). This is so small difference for the mic and speaker membranes that there is definitely no chance of damage, even with prolonged usage.

Usually this is not caused by the sleep tracking directly as this is usually not consuming too much resources (usually around 1-3% battery per hour of tracking).
The issue appears because we hold a wake lock (keeping the phone awake) – any badly written apps may access the CPU extensively during the sleep tracking time. We suggest checking which services are running before you get to sleep.
For us it is hard to debug this. Also battery statistics are not a hint here as all battery consumption is accounted to the app which holds the lock even it did not consume the battery – this is by design in Android.

To conclude, this issue may happen, although we did not get any similar reports for a very long time now. But the most probable cause is some wrong 3rd party service or app on your device.

To see more on the issue we would need a debug report (menu > report a bug).

A good test would be to reboot your phone before sleep tracking (or kill any unnecessary services running) and see if that helps.

At first Sleep as Android may look complex with all its options, but in fact it is fairly easy to get started improving your sleep and wake up.
You can delve deep into all the amazing options Sleep as Android provides later on. But to get started just rely on our carefully selected defaults.

This can be the result of several things, so please try the following troubleshooting steps:

We have had reports of audible artifacts during sonar tracking on some devices. It sounds like this:

Some of the signal gets into the audible range, probably due to either insufficient speaker quality or some post-processing applied to the output by your device’s firmware.

We also have some reports that Sonar can suddenly become audible while tracking at night. Unfortunately, we are not sure why this might happen, we have very few such reports, and we are not able to reproduce this on our phones.

To make any audible artifacts less likely:

If you get completely flat graphs with automatic tracking with sonar sensor after upgrading to Android 11, make sure the app has permission Draw over other apps, Display over other apps or Appear on top (Samsung).
This permission is necessary for accessing the microphone from the background.

If the tracking stops completely after few minutes, the background processes are restricted by your system.

If you notice your volume gradually dropping after a while while tracking is running, the Turn off when sleeping is enabled. This feature lowers the system-wide volume, so it also affects music played outside of Sleep.

Unfortunately, this also affects media volume in third-party applications, and we cannot control those separately from Sonar’s media volume. This means that while using Sonar, you can only use media applications at full volume.

You can set a time delay to start tracking in Settings → Sleep Tracking → Awake Detection → Delayed Sleep Tracking.

Usually the battery consumption issue or related issues that cause the phone to overheat during sleep tracking are not directly caused by sleep tracking.

In most cases, sleep tracking itself does not consume too much battery (usually around 1-2% per hour of tracking). But because we keep a wake lock (keeping the phone awake), any other apps and processes can access the CPU extensively during the sleep tracking time. We would suggest checking what services are running before you go to sleep. Also, battery statistics are not a clue here, as all battery consumption goes to the app holding the wake lock, even if it did not consume the battery (this is by design in Android). This is hard for us to debug.
A good test would be to restart your phone (or kill any unnecessary services running) before using Sleep as Android and see if Sleep as Android still uses too much battery after that. One of the features of Sleep as Android that may cause higher CPU load during tracking is the noise recording. You can try tracking without it as a reference. We also strongly recommend tracking with airplane mode enabled.

The red block indicates that something went wrong with tracking at that time and the device stopped providing sensor data for some reason. Usually those are some non-standard battery optimizations or battery savers, the battery gets too low so we preserve it for the alarm or connectivity issue if you use a wearable.

Unfortunately, due to security restrictions introduced by the Android team in 4.2, there is no way to automatically enable airplane mode from an app. You always have to go into settings or long press the power button. If you have a rooted phone you might consider using https://play.google.com/store/apps/details?id=lv.id.dm.airplanemh we have support for this in Sleep. A similar hack exists for 4.3.

If you don’t agree with the Android team’s design decision, you can upvote issue 40497 here http://code.google.com/p/android/issues/detail?id=40497.

There is no clearcut answer to which day the sleep between them belongs.

We have decided to attach the sleep to the day after, because how you slept will largely determine how your day will be.

If you have separate mattresses there is minimum interference from your partner. If you have one big shared mattress (which isn’t recommended as you partner may need different mattress for his healthy sleep), it could still work assuming you keep your phone close to your body and ideally on your side of the bed.

You can also consider using a armbands or smartwatches. This certainly solves the problem for a little convenience trade-off.

If both of you are tracking, you can enable pair tracking, which filters out the partner’s activity.