Sony announced at IFA 2018 today that it is bringing Amazon Alexa support to a number of its headphones as well as its HT-ZF9 Soundbar. This is going to allow users to control their Sony audio products with Alexa. The way Alexa is implemented here, is that you'll be able to install a skill on your account to control these devices through an Amazon Echo or another Alexa-compatible device. Unfortunately, Alexa is not going to be baked in here, Alexa can just control these devices. It is the most useful on the soundbar, as you can tell Alexa to turn up the volume while you are watching a movie.
Currently, Sony is not mentioning which wireless headphones will be getting Alexa support, with a future update. But it is likely going to be Sony's newer headphones, including the WH-1000X M3's that were announced today at IFA. Sony expects the firmware update for Alexa to come out in the winter, for its wireless headphones, while the HT-ZF9 soundbar will get it in the fall. On top of getting Alexa, the soundbar is also going to get multi-room functionality with Alexa, and that update will come as a separate update a bit later on - Sony is currently targeting winter for that update. It's also worth noting that these updates are going to vary based on the country, so Europe may get these updates before those in the US do.
Amazon Alexa has been added to a ton of devices at IFA so far, so it's not a big surprise to see Sony jumping on the train and adding it to its own devices. Sony added Google Assistant to a number of headphones last year, and now that it has Alexa coming, it means that the two most popular assistants will be available on its headphones. Making, what are already really good headphones, even better.