noise removable

I am using 1.2. I have a hum for about the first 10 min of the recording(80 min). I selected a few sec(3-5) with the analyze in noise removable, then selected the 10 min, then went to effects and noise removable. It removed the noise but totally changed and distorted the voice. It is speaking not singing. What do I do to get rid of the hum and keep the voice sounding normal.

1). the noise removal tool in Audacity 1.3 is much better than 1.2
2). If the noise is mains hum could try this dehummer plugin.
3). Applying Noise removal or de-hum almost always has some unwanted effects, ideally these are less obtrusive than the original noise/hum.

Thanks Trebor,
I was reading about 1.3 and was not sure I should use it on xp by some things that were said.

Audacity 1.3.12 is good on XP (I use it all the time :wink: )