As I described with the post on Tech For The Visually Impaired Student, work with the specialist to make sure what you are doing is going to work with what the specialist wants. In this case, it was an audiologist for a student who had recently gotten cochlear implants in both ears and was learning to speak.
Because of how the implants worked, I spoke with the audiologist about what could be done to allow the student to better hear from a computer, without trying to use headphones. The teacher was already using a wireless microphone with a transmitter so the student would be able to hear the teacher speaking. The answer?
From Radio Shack
The transmitter for the teacher's microphone also had a 1/8" port on it, allowing me to plug the student's transmitter directly into the headphone port on the computer itself. The student was learning to speak and chatting away by year's end.