8kHz strange output

Hi everybody,
I have some 8kHz 16bit mono recordings, some made by me and some by other people, they sound different in Audition compared to other programs: I tried the windows sound recorder, Winamp, VLC, and Windows Media Player 11 and they provide an identical output, while in Audition they sound different: less bass, some distortion. I noticed that if in Audition I convert them to 44100/16/mono they now sound identical as to the other programs. Can anyone explain me why this happens?
Thank you
  Clausfor

The other programs are, most likely, transcoding to 44.1/16-bit in real time.  I do not believe you can stream DirectSound at 8-bit resolution, hence the reason...but I may be wrong on this.