Hi I have trouble with editing channels separately. Is it possible with audacity?
To edit the channels of a stereo track separately, split the stereo track into separate left and right channels.
Click on the name of the track and from the drop down menu select “Split Stereo Track”.
Hello!
Thank you, but I have a bit more complicated problem.
I’d like to find out If I open a file, then I import another they are appearing in two channels. but I’m not able to mark only one channel. So whatever I’m doing with one channel the same thing happening with the other too. I cannot delete or move forward or backward one part only one channel.
Thanx for any help.
OK, so you actually have two separate stereo or mono tracks.
You should be able to make a selection in one track and modify it without affecting the other tracks.
Do you have Sync-lock tracks on?
http://manual.audacityteam.org/man/Sync-Locked_Tracks
– Bill
Yep, that was that! 
Thanks Bill, very much.
You saved my life!