Ableton Forum

Perhaps its already been addressed, but here is one option:
-download itunes app on Windows PC
-email yourself the iphone sound
-log into your email on the PC
-right click sound file, save to itunes
-highlight the file in itunes
-on itunes bar, go to file, scroll down and select convert
-select convert to AIFF
-a new sound file will be created below the existing rile
-this new AIFF file can be dropped into an Ableton track
Good luck!

Even simpler:

Install iTunes on PC.
Connect iPhone to PC using lightning cable.
Copy over the audio file(s) into iTunes then proceed as you suggest. Or burn the audio to an audio CD then import the track into the DAW software.