Google updated its Nest Hub smart home display for the first time since October 2018, highlighting new sleep tracking features alongside audio and processing performance improvements.

Though the second-generation Nest Hub retains the camera-free design of the original, Google said in a blog a new radar sensor will allow the device to monitor the sleep quality of the person closest to it by measuring their movement and breathing.

The company noted it previously used the sensor to enable gesture controls in its Pixel 4 smartphone, with the sleep tracking feature “the first wellness application” of the technology.

Nest Hub’s microphones and other sensors can be used to track disturbances such as coughing, snoring, or changes to light or room temperature. Google also plans to explore synergies with sleep-tracking features offered by its Fitbit wearables.

Google noted the sleep tracking tool is opt-in, with audio processed on-device rather than by the company’s servers.

Other improvements include a speaker offering 50 per cent more bass than the original; a Thread radio to control other smart home devices; and a dedicated machine learning chip to process common commands faster (US only).

The device costs $99.99, with ordering open to users in the US, UK, Canada, Germany, France and Australia: CNBC reported it will start shipping on 30 March.