Follow the procedure below to use iTunes for deleting audio files.
- Start up iTunes on the computer.
- Connect your iOS device to the computer, and then select the iOS device that appeared (from the icons in the upper-left corner of the screen).
- Select “Apps” (left side of screen).
- Select “iAudioGate” below [File Sharing] in the page that appeared.
- Select the file that you want to delete, and then press the Delete key.