The audio you share to iTunes can be found in the File Sharing section of iTunes on your computer, when you have your device connected.
- Connect your device to iTunes and select your device by clicking the button in the upper right corner (iTunes 11) or selecting it in the list to the left (iTunes 10 or earlier)
- Click the Apps tab
- Scroll down to File Sharing, click on Figure in the list and download your selected files, or press the Delete key on your keyboard to delete them
Read more about iTunes File Sharing at the Apple support pages.