The new feature is currently rolling out for the Amazon Echo, Echo Dot, and Echo Show devices, but eventually, all users of Alexa-enabled devices (including those made by third-parties) should be able to take advantage of this new ability.
An extremely useful addition for people who are sharing an Amazon Echo, voice recognition enables your speaker to tell who is talking to it and provide personally-tailored responses. So if you instruct it to call John, it will call your friend, not your roommates.
To set this feature up, you will need to navigate to Alexa’s app settings, find Your Voice and then teach Alexa what your voice sounds like by reading out 10 full phrases. Once you’ve trained the virtual assistant, she will store the information in the cloud and make use of it again if you purchase another Alexa-enabled device.
For the time being, Alexa will take advantage of its new skill to personally tailor calls/messages, flash briefings, shopping activities and music playback via the Amazon Music Unlimited Family Plan. However, Amazon promises voice recognition will be made available to other additional Alexa features sometime in the near future.