I think that the 3G will present unique issues with 3rd party voice modulation software, as it would depend on how sound is channeled with the software. Many times these programs create a virtual port for microphone output. Try editing your Microphone configuration in the SimMan interface, making sure to use the same input that the voice modulation software is using.
What software are you using?
Have you successfully transmitted your voice to the manikin without the software?
Another consideration is that the SimMan 3G operates with an XP computer built into the 3G body. It would have its own input output, and interfaces with the control computer, primarily, as a front end user interface. Sound is actually being transmitted from within the 3G's own computer.
I don't have a 3G myself, so I may be completely off base, but I thought I would give you some ideas to go on in the absence of other responses.
Let us know how you overcome this issue, as I'm sure you will succeed. If you haven't called Laerdal support, give that a try, although I would be surprised if they would give you any direction as 3rd party setups are typically not supported.
Michael Young
Technology Support Specialist
Tarleton State University
Center for Instructional Innovation
Assigned to: College of Science & Technology, Department of Nursing
254-968-9594 (Office)
254-967-5693 (Cell)