The Amazon Echo, Echo Dot, and possibly other Alexa devices will soon be able to synchronize audio across multiple devices. Users have reported seeing a new audio synchronization feature appear in the Alexa app. The feature, often referred to as whole home audio, will allow you to use multiple Alexa devices to play music as if they were satellite speakers connected to the same audio source.
You’ll be able to trigger multiple Alexa devices to start playing the same thing by adding “everywhere” to the end of a request. So saying “Alexa, play music everywhere” to one device will start playback on multiple devices simultaneously. You’ll be able to select specifically which of your Alexa devices are triggered, when the “everywhere” request is made, from within the Alexa app.
It does not appear as if audio synchronization is working just yet. Those who are seeing the new setting in their Alexa app are unable to select their Alexa devices to participate because the app states a firmware update for those devices is required. The app also states “saving will interrupt streaming audio and activate Bluetooth connections,” so the feature may use the Echo and Echo Dot’s Bluetooth signal to keep audio in sync. It’s unknown when the feature will make its way to all devices, but it should be coming soon.