AL H

I like to know the detail steps of removing a particular unwanted noise mixed with the speech in my audio. The auto noise reduction functions did not help. Using this auto function also reduces the quality of sound and getting lower. I just want to remove the paritcular noise only. I think I need to use " Grab noise sample from selected area for Spectral Subtraction" and Spectral Subtraction based on Sample" Am I correct ? I cannot find the help in the Help. I already watched the basic noise removing video tutor. It did not help my issue. 2) I also like to know more advanced noise reduction tutor video that explains each functions of noise reduction menu.

My Wavepad sound editor is not opening M4a file nor playing NOW. I could open M4a file and edited and saved it as mp3 before. Please help.