Using the Macs built-in text to speech functionality it is super easy to create custom ringtones for the iPhone.
- A Mac
- An iPhone
Open Terminal and create a ringtone audio file using the say command.
say -v Trinoids "Incoming Transmission" -o incoming.m4r
Pay attention to the folder you are in when you make this file, this will normally be your home folder.
Now go to iTunes and chose the menu option [File->Add To Library]. Navigate to the file you just created and select it. The audio file should be added to the Ringtones section of iTunes where you should be able to play it. Connect your iPhone or make sure it's on the same wifi network and appears in iTunes. Select your phone in iTunes and choose the Ringtones section. Make sure the new file is being synced by choosing "All Ringtones" or "Selected Ringtones" and checking the one you just added.
Now Sync your iPhone and TADA. The new ringtone should now be available for whichever alert you want to use it with.
For more information about the say command you can use man in the Terminal:
say -v ?
will give you a list of the available voices you can use.