May i connect with you remotely to check this for you? Thanks
Reluctantly I am against remotely because their are three computers involved and that scares me. I would much more appreciate a more verbal answer to the problem so we don't have to expose are selves thanks
Since they cannot hear from you, i would suggest that you check and switch your Mic from Tools -> Options -> Audio Settings. Make sure the mic is working, if not then it is the mic that can be faulty. Let me know. Remote would have been easier to test and troubleshoot. Technical issues are not always straight forward, and usually most of them can't be fixed with a one line answer.
Also ask parents to make a skype test call, and see if they can hear themselves during the test call.
We have done all that
Since you've done all that, i can not suggest anything else other then a faulty mic on your end, if it works for others and not just the parents, then it is something that needs to be looked at. However, since you don't want remote, we have the option here of letting other experts assist. This will make me opt out and open the question to them. Shall i go ahead and do it?
Hello are you saying that when they do a Skype test call they can hear themselves back please?