I think this message may lack informations, but I have no idea about
what I can give except those one...
OK, so you've established that your microphone is working. You don't
normally want to hear your voice back when you speak into it, so mute
the microphone output (but not the input). You should be able to use
the sound recorder to still record your voice and play it back but
you
won't hear it when speaking.
Skype has a pulldown menu at the bottom left of the skype window.
Select Options | Sound Devices and try the different microphone
devices until you find one that works with the Skype test call.