You could hit the little microphone icon next to the space bar and it'll listen to whatever you say. Or as Xrayeyes says, use Siri. It may take a little practice to get the sequence just right.
I'm super surprised at how accurate my voice texting was on the 5c. Only thing I couldn't figure out was the punctuation at the time. Heck it even put in a typo I'd spoken and it made me laugh. That's pretty good actually. Haha.