I play it on XB1, and it uses the voice recognition through kinect. Id assume the PC version has it using a regular microphone, or headset etc. It is a nice feature. You can do it all with the controller as well, but good luck navigating the little popup menu to select the commands while trying to drive at those speeds, on these tricky tracks. It does some cool things... some commands like weather update for those races where the weather may change from cloud to rain and back. You can ask for updates on your team mate, time to driver in front, or behind. etc. etc.
They have also done a pretty awesome job IMO with the handling of the cars. They're a real beast to drive with assists off. That being said, I do find the game very playable with an XB1 controller too. Sure, I can't keep up with the most difficult AI levels using my controller, but truth be told, I probably couldn't with a wheel either. The game though, plays very well with a controller.
Im not the biggest F1 fan. I watch occasionally. However, this game just makes you a fan of playing it because, as I said earlier it actually makes you feel like you're running a real F1 race, and dealing with the things they deal with, especially getting out of the racing line. I lost count of how many times Ive hit a fast corner, a bit off my line into the marbles, and just sliding... try accelerating out of a slower corner while in the dirty part of the track too. Good luck. lol.
I'll stop gushing about it now, but it's probably the racing game I enjoy the most, and I love Forza 7 and Horizon 2 & 3. Id say though, F1 has been my favorite racing game every year the last few years.
Hope you enjoy it as much as I do if you pick it up.