Sonar vs accelerometer, which gives better idea of sleep cycles?

Hello, just wanted to know if there’s any common thought or consensus on whether using the sonar or the accelerometer will yield more accurate sleep cycles (at least as accurate as we can get using a phone lol)?

Thank you!


Also curious about this!

It also depends on what device (phone) you have in how well it will operate with the sonar option!

but im also curious on wich would be the more reliable option to use… :thinking:

I think it depends on your sleep environment. I have too much white noise in the room for Sonar. I can’t even get normal sleep noises picked up. Plus I use both a body pillow and an extra pillow, and this will also likely block sonar.

But if you sleep like normal people :stuck_out_tongue_winking_eye: , in a quiet room with just a pillow for your head, I think Sonar should work just fine. I have tried it in other settings, and it works fine.


+Robin big thanks for the insight… we do maximum to filter any non-ultrasonic whitenoise or any other audible sounds in the room, we do a high order high pass filter on the sound before we do any analysis of the ultrasonic signal, but of course this is not 100% and noise in the room may have a slight effect on the final resolution of the algorithm… but I think what is more important is really the HW and SW of the phone and how well it is suitable for emitting and recording ultrasound…

So IMHO Sonar is a very good option if you are charging over night (as it consumes much more battery than accelerometer sensor - it is basically playing sound all nigh on max volume) if it is well supported by your phone in this case it can even detect breath rates (which you see as a blue line on your graph)… so it is very sensitive, gives you comfort of not having phone in bed…

If you have any issues with Sonar, like artifacts of the ultrasound being recorded, or it does not react well to your movements during sensor test or you want to play music through the media stream instead of Sonar… than use rather accelerometer… or even better a wearable on your wrist which can also very well detect high activity awakes…


Thanks for the swift reply! :grinning:

Perhaps I will give it a try for a night, but I have a very, very reliable wearable (two Pebble Times in new condition since last year), and I use sleep music/sounds/lullabies in addition to the white noise. Other people find it all quite loud. I am very used to it. If there’s a power failure, I am up until power is restored. Just different strokes for different folks. Sonar is handy for naps, though. It works well.

It would be amazing if the sonar could make it through my white noise, though. Because the snoring-feature microphone picks up no sleep sounds whatsoever: no snores, no random noises, no talking, nothing. I hear the white noise, though. Perhaps if it can use the microphone on a sleep Bluetooth headphones, which I often use for the binaural beats. It has a microphone for phone calls.

But it’s really okay this way. And I will give it a try soon, just out of curiosity. :slightly_smiling_face:

All the best!
P.S. – Five years ago, I used an old Note 2 in the bed, tucked under my head and shoulders inside a pillow case. Amazing that I didn’t become a human torch. The Note 7 catastrophe was instructive about lithium ion batteries and I will never again have the phone in the bed. Ever. There are so many options!

I just got a Mi Band 4 and tried it last night.
I woke up at 7:40 and tried sleeping until 8:20.
The app considered I kept sleeping the whole time (I did not sleep at all between those two hours.
By the way I turned on my phone at 7:40 but sleep as android did not considered I was awake at this time, the graph shows me I was asleep the whole time.

I’ll try it again this night and will activate constant detection for sleep and heartbreak (every minute) and come back here to say if it changed something.

No luck, it says I was sleeping at a moment where I woke up and did huge arm movements (had to shutdown the alarm of my old phone I forgot to shutdown)

Scusa, con Oppo A9 , mentre prima funzionava, ora al test sonar sleep android mi dice che il sistema impedisce mandare ultrasuono , non supportato .

Hello @Claudio_Cortese … try other modes F18, F19, F20… also check that everything si properly setup, your sounds are not muted etc…