This audio codec should be natively played in both VLC and QT.
If not, then it might be either a settings related issue or a codec corruption.
As the first attempt, Reset the preferences in VLC media Player.
Open VLC. Go to Tools > Preferences > Reset Preferences.
If still it behaves the same, I would suggest you to re-mux the video with a different audio codec. There are many freeware tools that can do it, I prefer AVIdemux for this purpose.
Download and Install AVIDemux
Open it, drag the video in the window.
3. Under Audio Codec, Set it to either AAC, or AC3 or MP3.
4. Then, File > Save.
5. In the save dialog, dont forget to put the extension name, .avi.
Hopefully the issue will be gone then.