Creating iPhone Ringtones
The iPhone allows you to set custom sounds for when you receive a call or text, as well as for when an alarm goes off. You can even assign specific tones to individuals, so you can tell who's calling or texting without even looking at the phone. Using Fission, you can turn any audio file into a tone for use on the iPhone.
To get started, just open an audio file in Fission and select the audio you want for the ringtone. Once you have your audio selected, use the Crop function to trim out any unwanted audio. Remember that iPhone ringtones need to be less than 40 seconds, and you'll likely want a very short (1-3 second) file for text tones.
After the rest of the audio is removed by clicking Crop, this file will be ready to be saved as a ringtone.
After cropping down your audio, play it to confirm it's exactly what you want, then select Save as iPhone Ringtone from the File menu. Fission will then process the file and pass it directly to iTunes. Your new ringtone will immediately appear in the Tones section. Sync it over to your iPhone, and you can start using it immediately.
The iPhone's Tones section in iTunes