I could be wrong, but I am thinking that the problem might lie with what the
Skype people have done to Skype for either Kindle or perhaps even android: I
tried it with ear buds to see what would happen, and the other person still
sounded faint, no matter what I did with the button for audio settings. I went
into the device setting for managing apps, and saw that for Skype, among the
permissions you are agreeing to is one for controlling the audio volume of your
system globally, I.e. I believe across the whole device. There was no way I
could see to disallow that. On my Apple devices everything is how I would
expect. The same thing held true for Skype from the play store, and another
product that is under development, that they say is for the market in India,
but which apparently we can use, called Skype light, meant for use on lower end
devices or slow cellular networks.