Insert the CD recording into the CD drive on your computer. Launch the digital audio editing application.
Select “Open” from the “File” menu in the digital audio editing application. Use the file browser to navigate to the CD. Select the first track, and click “Open” to extract the audio from the CD.
Perform a noise removal. Every audio application performs this process differently. Consult your software’s documentation for details. Highlight a portion of the waveform that is only noise (no music or speaking). Select an appropriate command such as “Get Noise Profile” or “Sample Noise.” Highlight the entire waveform. Choose a command, such as “Remove Noise” or “Suppress Noise.”
Save the new audio file into a separate folder. In the audio application, choose “Save As…” or “Export To…” Specify WAV or AIFF as the file format. Do not save as MP3 or any other format that may result in compression of the file and loss of audio quality.
Repeat Steps 2 to 4 for every track on the CD from which you want to remove the hiss or other background noise.
Eject the audio CD. Insert a blank CD. Use CD-burning software to write your cleansed audio files to the blank CD.