teething problems

As I have said its very easy to teach on-line...that is unless you develop a technical hitch of course.Yesterday we had sound problems and today they were no better.I could hear my students but they could not hear me.The frustration is very strong!!I did all audio and sound checks ,my mic was fine according to the computer but two students in a row could not hear me and so we had to cancel the lessons...got students tomorrow so will fiddle about with wires and connections in the hope that I can get it sorted out.Wish me luck!