Yes you can but you need to download software to convert from one to the other. There are plenty of free downloads on the Internet. Here's one that I came across - don't know if its any good or not.
Download "audacity" from http://audacity.sourceforge.net/ This is a great free programme which converts all kinds of audio. It can record audio from cd, youtube, dvd, the internet generally and convert to different formats - mp3, wav, ogg vorbis etc. You can create ringtones with audacity - taking sound samples from various sources. Audacity is like a digital sound studio and very versatile - use the help files and learn new techniques