What are the pros and cons of "cell phone listening" and "mp3 listening"?

From the aspect of sound quality, a bunch of cases, MP3 listening to songs is better than cell phones.

1, MP3 as a professional music song playback software, its sound, bit rate and other aspects of the specific optimization, its sound quality is better.

2, ordinary cell phones as long as the satisfaction of the call text messaging function, music playback is just a subsidiary function of its own self, play music naturally not as good as MP3.

3, but in terms of portability, most people still choose to use the phone to listen to songs.