Inconsistent audio levels

Hoping someone might be able to assist me with some audio recording issues I'm having with Audition. When recording audio, on playback, the initial volume is very quiet for about 15 seconds, then it gradually increases in volume. Any idea why this might be happening? I'm using a Logitech USB headset 540, and I've tried uninstalling and reinstalling Audition. I've also checked my recording levels on my computer which were set at 80 and after reading a post, changed the right to 100 and the left to 0 which seemed to work for someone else with this issue, but unfortunately not me. Any suggestions would be appreciated!