Results of 64kbit/s Listening Test
Interestingly venerable MP3 codecs fair better than more recent Windows Media and Quicktime.
1. No codec at 64 kbit/s can claim to be as good as mp3 at 128 kbit/s.
2. High efficiency AAC (AAC with spectral band replication, similar to mp3 with SBR, aka mp3pro) makes a good first showing, being the first among equals (he-aac, mp3pro, and ogg vorbis).
3. WMA9, Real, and Quicktime AAC make poor showings. While better than the hoary mp3 at 64 kbit/s, they are definitely worse than the top three 64 kbit/s contenders.