Amazing Test---Mp3,OGG,WMA10 Pro format comapring at low bitrates!

I use the sample music WES - Alane (Radio-Mix).wave (size 38Mb, CD Name: Summer Time Hits 3rd CD) as the source file to test. Then I've transferred it to different formats at low bitrates 64k bps:

Then I use the wave editor to generate their frequency spectrums.

The original wave spectrum:

The mp3 wave spectrum:

The ogg wave spectrum:

The WMA wave spectrum:

Conclusions:
1. Apparently the MP3 frequency reaches maximal approximately 12000Hz, which is very unsatisfactory to listen as voice instead of general music. Comparing with mp3, OGG reaches highest frequency of 16000Hz, this is much better than MP3 (its quality almost reaches the level of MP3 at 128kbps, which can be frequently heard from the official website as well as some official audio testing). So it is not surprised that a lot of audio magazines call the OGG format the killer at low bit rates (<128kbps)>
2. What a great surprising is that, the WMA amazingly reaches the highest frequency of 21000Hz! It nearly fits the original wave unbelievably. So the new WMA10 Professional codes which is promoted by Microsoft is really powerful, it theoretically provides much higher quality of music at smaller size at 64kbps comparing to OGG format(from the figures) as well as its former WMA9. However, the open source project OGG music format is becoming more popular currently and it’s expected that it will replace the MP3 in the future, as long as more content providers or music companies give support.

3. For voice or stream application, it is pretty wise to choose WMA10 or OGG, but the popularization of WMA10 may still have a long way to go because of its patent fee, unlike OGG---an open source format can be accepted much easily by electronic manufactures.

Therefore quality ranking: WMA10 (64kbps)>OGG (64kbps)>MP3 (64kbps)
WMA10 Pro: ++++++
OGG: ++++
MP3:++

Attachment:
The same sample music file is transformed using WMA9 codes; it’s only a little bit better than mp3 above.

Links:
Lame MP3: http://lame.sourceforge.net/index.php
OGG Vorbis: http://www.vorbis.com/
WMA:http://www.microsoft.com/windows/products/winfamily/mediaplayer/default.mspx