is it legal to use Google Speech Api in a Stand Alone Commercial Software

Hi,

This is Fatih Barut. A programmer. I had a recent idea adding speech
recognition to my program. And the best way was using Google Speech api. I
did it. Now I have a speech recognizing program. On the other hand I want
to sell this program however have no idea whether it is permitted by Google
or not?

I would be very appreciated if you could enlighten me
With best wishes.
Fatih Barut