https://www.cnet.com/news/sonys-wh-1000x-series-noise-cancelling-will-get-amazon-alexa-support-ces-2019/

Alexa set-up in Sony's Headphones Connect app.

To access either voice assistant you'll still have to tap a button. You can then use your voice to ask Alexa (or Google Assistant) to play music, change tracks, control smart home devices, search the internet for information and more. Of course, you'll have to have your headphones connected to your phone (or internet-connected tablet) to use voice controls.