Thanks. I thought about doing it the "echo" way where it is always listening for a control word like echo does, that way when you have a radio without DTMF you can still use the system. The problem with that is the free version of the voice api limits you to 50 (they say) transactions a day.
I also did this same thing with sphinx which is an offline voice recognition software. It works the same, but not nearly as accurate as the google engine. Then again it could all be based off DTMF pretty easy like the skycommand system was. I have a text to speech function so when I hookup a transmitter it can read back setting to confirm they are correct.
There isn't really any "purpose" to this system other than it was an extension of something else I was working on. It isn't designed to change the way we do ham radio just a fun tool.