In it’s quest to put an Echo device into every room in your home, Amazon has quietly begun rolling out Echo Spatial Perception (ESP) in the latest software update for 1st and 2nd generation Echo and Echo Dot devices.

ESP is the much anticipated feature revealed when the Echo Dot 2nd gen was announced, that allows several Echo and Echo Dot devices within listening range of each other to correctly identify which device is closest to the person interacting with them. This makes it so two devices don’t respond to the same voice request.

As some users have commented, software update 4008 seems to include the first release of this ESP feature. The new software build is to be hitting the first-generation Echo and Echo Dot, with expectations of the second generation Echo Dot being updated in the coming weeks. The second generation Echo Dot is shipping to U.S. customers on October 20th.

Update: As referenced on it appears software update 4148 includes ESP and not 4008 as reported earlier.