Our sleep tracking system tries to use all the data available to it - including accelerometer data, ambient light data, filtered microphone input and more.
After speaking to Sleep Experts, we don't track levels of sleep such as REM as we were advised that this wasn't the most accurate way to analyse good sleep. But we do track Awakenings, Sleep Opportunity, Sleep Quality, Sleep Regularity etc - which helps us build an accurate Sleep Score.
In order to record data correctly however you do need to ensure it is set up correctly:
Please ensure your phone is on charge to ensure your phone has enough power to track your full nights sleep. Data is only saved at the end of tracking, so if your phone powers-down during the night then no sleep tracking data will be saved.
Place your phone on the corner of your mattress, with any cables safely tucked away to avoid strangulation risk.
Ensure your room is dark and windows are closed so that no loud noises from outside get picked up. While the app will filter out Sleepiest audio - other background noise can inadvertently lead to the app detecting you as awake when you're not.
If you find that your sleep data still seems incorrect, you can use the 'Pen Tool' when viewing your Sleep Score to edit your Sleep Opportunity and Awakenings.
Note: Sleep tracking is a relatively new Sleepiest feature, and is something currently undergoing continuous refinement.