Disabling speech

I am using Tiger Server and a mix of Tiger and Panther clients. We are in a school setting and I would sooooooo like to use workgroup manager to disable the "speech" tool on the client machines so that the students cannot make the computer say what ever they want. I have been looking but have been unable to find a way to do this other than going to the individual machines and taking away all access to the "speech" folder in library. This is what I had done on a couple machines but this would be too timely to go to all and do this. thank you in advance.