In ROBOTC, where in the motor and sensor setup do I declare a VEX speaker?
you don’t, it plugs into a dedicated port on the cortex.
The one labeled SP next to digital IO 12
There are websites that will create a wav file from typed in text. Write something out that you want your robot to say, run the resulting wav through audacity (free audio editor) to convert it into the correct file format, then load it to the robot.
The girls did this and had the robot introduce itself during judges interviews by assigning buttons on the controller to play certain audio files. Came off as pretty neat.