The issue is that the audio is encoded with a codec that isn't supported by VLC. If it's not supported by VLC, then odds are there are no free programs that do. You're basically going to be stuck using QuickTime for those specific files so you have my sympathies.
if you ready to give up .mov formats than try "handbrake" to convert your files into mp4 or mkv..
or .mov is your's priority , then download "format factory" and choose all to MOV( yes .mov to .mov, but if your older files may have some codec issues, this will fix it)
just try with 1 file to check, if converted new file works fine vlc, then you may convert rest of your files
both handbrake and format factory are freeware, so just give a try
what camera you got,, brand and model number...
generally vlc has it's own codecs , so no choice for any codec pack for it,, better get klite codec pack & try to play the video using media player classic or any other player ,