Quality of sound in narration

I tried Articulate Presenter for the first time over the weekend and build a lesson. For each slide, I had text and pictures and was able to add narrative to each slide.  The problem is that the quality of the narration is bad.  It sounds like the narrator is talking into a tunnel.  The room was completely quiet and I used a microphone plugged into the USB port in my laptop.  Any suggestions to improve the narration quality?  (How can you confirm that the narration is going through the attached microphone and not just through the computer build in microphone--usually you can tap a microphone to check if it is on/working, but my microphone did not make the typical noise when I tapped it, it made no noise). Thanks.