Available as a free preview until next year Sleep Sensing uses Motion Sense (powered by Soli low-energy radar technology) to analyse how the person closest to the display is sleeping, based on their movement and breathing - all without a camera or wearable.

Sleep Sensing can also detect sleep disturbances like coughing and snoring or the light and temperature changes in the room with Nest Hub's built-in microphones and ambient light and temperature sensors, Google said in a statement on Tuesday.

"We'll also be looking for ways to work with Fitbit's sleep-tracking features in the future," said Ashton Udall, Product Manager, Google Nest.

Sleep Sensing can also connect to your Google Fit app on Android and iOS devices, so you can see your sleep summary alongside your other health and wellness information.

The company said that Sleep Sensing is completely optional with privacy safeguards in place.

"You choose if you want to enable it and there's a visual indicator on the display to let you know when it's on. Motion Sense only detects motion, not specific bodies or faces, and your coughing and snoring audio data is only processed on the device -- it isn't sent to Google servers," Udall said.

Even if you don't enable Sleep Sensing, you can still fall asleep and wake up easier with Nest Hub.

When it's time to wake up, Nest Hub's Sunrise Alarm gradually brightens the display and increases the alarm volume.

The second-generation Nest Hub comes for $99.99 and can be preordered online in the US, Canada, the UK, Germany, France and Australia.