September 12, 2004 - Removing Light Hiss With Cool Edit Pro

REMOVING LIGHT HISS IN 8 EASY STEPS

by umboto

So, you have a song on tape which you really really want to include in your next mix.  You record it onto your hard drive, and give it a listen.  It's pretty good, except for that pesky tape hiss.  This little procedure will clean up the hiss with very little signal loss.  We're going to reduce the track to nothing but hiss, save the hiss to a clipboard, invert it and mix paste onto the track.  When it plays back, the inverted hiss will cancel out the hiss you hear.  If you wish to stay on the safe side, work with a copy of the track, keep your original just in case.  OK, here we go...

1.  Open the file you wish to clean up.

2.  Edit - Convert Sample Type (we're going to work with a 32 bit float).

When the window opens, on the right side, under 'Resolution', select 32, then click OK.

3.  Transform - Noise Reduction - Hiss Reduction

Or, this shortcut:

Select 'Light Hiss Reduction'.  If you are dealing with a lot of hiss, try either 'Standard' or 'High' reduction, but keep in mind the more aggressive you are, potentially you will lose more actual signal.  (Losing some of those highs and lows)  So be willing to experiment.

Check 'Keep Only Hiss'

then click 'OK'.

4.  Edit - Copy (Save to clipboard)

5.  Undo the hiss reduction

6.  Edit - Mix Paste

Make sure 'Lock Left/Right' is checked

Check 'Invert'

Make sure 'From Clipboard' is checked.

Make sure ‘Overlap (Mix) is checked.

Click 'OK'.

7.  Edit - 'Convert Sample Type' (back to 16 bit).

This time, make sure '16' is selected in the 'Resolution' window.

Click 'OK'.

8.  Save the file, you're done!