Digital Audio Format for Handphone

Now a days when you have a phone which can works like a MP3 player, the thing that you want to have in it is songs and mostly people will put in the songs under MP3 file (eg: .mp3). I used to put that type of audio files into my 256MB card but only able to fit in around 30+ songs depends on the quality of the encoded song.
So, while I was having a break from my exam revision, I found something which i think useful for those who wants to fit in more audio files with less space. Introducing AAC HEv2 codec encoding or known as eAAC+. With this encoding, you convert your other audio file to something.m4a which now a days most handphones and portable audio devices support it. I found out that the size of a song from the initial 6MB(mp3 file encoded using MP3 LAME-one of the best quality) to around 2MB only!!
Many sure things that the quality will be very poor as the file size is so small but surprisingly the quality is almost as good as CD quality which hardly able to differentiated between the file before encoded. Maybe my earphones(HPM-70) is not the best in the market but seriously to those who wants to fit lots of songs into your audio device, this is quite a good choice.