The Amazon Echo and Echo Dot speakers, which were first shown at the Amazon Event earlier this month, will now transform your warm places into smart spaces by detecting motion and occupancy in your house. The latest Echo and Echo Dot speakers can detect the presence of people in a room and switch on and off connected devices like your lights or Fire TV by using “inaudible ultrasonic waves.”

Using the Alexa app, users will be able to activate or disable this capability. Another amazing aspect of this new feature is the ability for users to configure occupancy schedules to turn on lights when they enter a room and then turn them off when no one is there. Also, Alexa may start playing music or a radio station as soon as motion is detected near an Echo device within a certain time period, and then stop playing music when the motion changes. All features are displayed under Motion Detection in the Alexa app settings for different compatible Echo devices and may be toggled on or off there.

The motion-sensing capabilities of the newer Echo Show devices are quite similar, with the exception that they use cameras to identify the presence of humans in a location. The Echo speakers do not have cameras; instead, the gadget detects motion by releasing an inaudible ultrasonic wave that bounces off adjacent objects before returning to the device’s microphones.

Google is another tech behemoth that has successfully used ultrasonic capabilities in its smart products. The Nest Smart Displays and Nest Mini Speakers can recognize when a human is near to the display or speaker and provide several interfaces. Volume controls exist on the Smart Mini speakers, but, unlike the newer Amazon Echo and Echo Dot speakers, they do not presently provide the ability to utilize ultrasonic detection to activate Google Home Routines.