I think most people are just using Amazon echo for voice control. It works great with smartthings, and it has amazing far field voice recognition hardware, but it doesn’t give you the context information (which room you’re in) that you’re interested in. “Lights” would always be the same thing unless you put a different Amazon account on each Amazon Dot.
There are two other ways that people have done it. The easiest is probably just using a combination of Tasker and sharp tools on any android device. Then each device would have a meaning for “lights” which was specific to that room. So you would need one android device in each room, but they’re pretty cheap. @joshua_lyon can say more about that.
There’s also a community member who built himself a whole house system using multiple hardware and software pieces.