You can buy Voice Attack (there's a free trial but limited to ~15 commands IIRC). On its own it won't do much, but you can then install Voice Packs. There's commercial ones (eg, from HCS) as well as free ones (eg, KICS). They may require a greater or lesser effort to configure to your keybinds; I set mine up a very long time ago and heavily customised it at the time so I don't know how easy it is to set up the current crop.
You can also use EDDiscovery (free) which has learned voice commands in the last year or so; personally I haven't used this so don't know how well it works but it seems to autoconfigure based on your current keybindings which is rather nice.
Apart from functionality, which you can probably tweak to be similar no matter what you use, the main difference is that the commercial packs mostly have professionally voice-acted responses whereas free offerings mostly rely on the Windows speech synthesis. Immersive difference.
I use VA (Voice Attack) with a heavily modified version of KICSv3 with bits of KICSv4 thrown in. I also have EDDI running as a VA plugin which adds a tremendous amount of in-game information via voice (handy when flying in VR).
EDIT: PS. HCS currently has a sale on one of their Voice Packs which is voiced by William Shatner for £5, if that's your cup of tea.
Point about the recommendations above about headsets. If, like me, you use a speaker system and wish to keep using it in E D then you need to experiment with microphones to get VA to just respond to your voice and not be confused by the sound from the game. I have loads of microphones so had plenty to choose from, in the end the best results come from using a dynamic microphone - basically like the ones you see used on stage. I find that using condenser microphones should be avoided if you are using speakers as they are far too sensitive.
I agree you don't need HCS - but I can't fly without my crew these days - makes up for the abysmal in-game comms with other players so it is not just for automating game actions. Worth watching for sale promos for them, often 50% or more discounts available.