To convert an M4A file to WAV in iTunes, change the encoding format in the Import Using menu in the Importing Settings preferences, and create a WAV file out of the file afterward. You need to use a non-Protected AAC file.
- Open Importing Settings
Launch iTunes. If you are on a Windows system, go to Edit, and select Preferences. If you are on a Mac, go to iTunes, and select Preferences. Click General, and select Importing Settings.
- Choose an encoding format
View the Import Using menu from within Importing Settings. Choose the encoding format that matches the format that you would like to convert the file to. In this case, select WAV. Click OK to save your preferences.
- Convert to WAV format
Select the song that contains the M4A format in your iTunes library. Go to File, and select Create New Version. Choose Create WAV version. If you would like to convert an entire folder, such as an album, hold down Shift on a Windows system or Option on a Mac, and click File. Select Create New Version, and select Convert. To convert a song that does not yet exist within your iTunes library, convert the file as you import it into iTunes.