No sound on Garage Band playback
I am brand new to Garage Band and am trying to record an audio book.
I have set up a usb-connected microphone to my MacBook Air. I have changed the input to reflect the microphone. When I attempt to record a track, it seems to be working. As I speak into the microphone, the track shows the squiggly lines that would seem to indicate it is recording my voice onto Garage Band. But when I go back to the beginning & hit the play button, no sound comes out.
I have tried playing music on my computer to make sure the audio is working, and it is. I've tried using headphones, but no sound comes out with or without headphones. I've checked all the possible common sense trouble shooting I can think of, but no sound comes out.
Suggestions appreciated.
MacBook Air (13-inch Mid 2013), OS X Yosemite (10.10.5)