The mp3 file has a couple of issues I want to touch on. First off, the 15 second period of silence at the end should be cut, it serves no purpose. Second, the mp3 file shows compression artifacts consistent with YouTube, which compress the file down to 128kbps. This means that the audio file was ripped directly from a YouTube video, and is not the highest available quality. To summarize, I recommend trimming the mp3 a bit, and also getting a higher quality mp3.