Okay then I assume you have the DLL with you. So you should have the documentation of that DLL also. That is you must know the functions available, what the functions do, and what are the parameters the functions need to execute properly. After looking up for those in the documentation you can refer this site, which is an example on How to call the function in the . I think it is fairly straightforward, but you can ask if you run into further problems.

I must also say that I appreciate what you are doing to help those kids with speech problems.