here is a demo of various low bitrates codecs, here being used to Code-Decode music, music, i need to really get some speech for them to compare also, (not my voice!!!)

Thanks go to Cokemaster for allowing me to host these.

the first 5 are 500k downloads, the final is 2.7MB

First up, Simple, Old ADPCM (ima)
ADPCM 32Kbps, Original Size 124KB
SBC, one of the Windows Codecs,
SBC 21Kbps, Original Size 76KB
GSM 6.10, Before EFR
GSM 13Kbps, Original Size 52KB
CDMA Qualcomms Qcelp codec, based on old ACELP, currently a "surpassed" standard.
QCELP 13Kbps, Original Size 52KB
AMR (adaptive multirate) as currently used on Vodafones UMTS 3g network.
AMR 12Kbps, Original Size 48KB
LBfmt, What can you squeeze into 15Kbps., why don't mobile networks sound like this... Imagine......
LBfmt 15Kbps, Original Size 56KB

Let me know any comments please!