CDA, which stands for "Compact Audio Disc," is a small shortcut file that Microsoft Windows uses to track the time and duration of songs on an audio CD. When you copy music from a CD to your computer, perhaps the songs may not play because of the incompatibilities between your music player and the audio files. However, you can convert CDA to MP3 using Windows Media Player, iTunes or a third-party CDA to MP3 converter.
Windows Media Player
Click on "Tools" and select "Options" in Windows Media Player
Click on the "Copy music from CD" tab in the "Options" window.
Select "MP3" from the "Format" drop-down menu under "CD Copy Settings".
Move the selector under "Audio quality" to the far right next to "Best quality". Files converted from CDA to MP3 will be slightly compressed and will result in poor quality audio as a result. In Windows Media Player, 320 kbps will produce the highest possible sound quality.
Click on "Apply" and then "OK."
Insert an audio CD into your computer's disk drive.
Click "Copy from CD" at the top of Windows Media Player. The program will begin to automatically convert all CDA files to MP3 files.
Wait for your computer to automatically eject the audio CD from the disk drive. Songs that you have copied can now be played in MP3 format without producing CDA file errors
To convert CDA to Mp3 you'll need a couple items
1. A PC or a Mac
2. An audio converter application
Then you'll have to open your CDA file on your converter, and convert the files you need to mp3.