VLC is an infinitely better video player than Windows Media Player, so it's a good idea to have it on your PC. It's a free download, here:
http://www.cps.gov.uk/legal/h_to_k/homicide_mu rder_and_manslaughter/
VLC can play QuickTime videos. Click on Settings > Extended GUI > Equaliser
Click 'Enable'
Set the 1kHz in the middle of its range. Push the 3kHz slider to the top. Drag the other sliders to the bottom. (That should provide a good starting point for the filtering job that you're trying to do, but you might need to experiment a bit with the settings).
Chris