3GPP Adaptive Multi-Rate - Wideband (AMR-WB) Speech Codec
(3GPP TS 26.204 V7.0.0)
http://www.3gpp.org/ftp/Specs/html-info/26204.htm

AMR-WB is a speech coding standard developed after the AMR using the same
technology like ACELP. The codec provides better speech quality due to wider
speech bandwidth of 50-7000 Hz compared to narrowband speech codecs.
AMR-WB is codified as G.722.2, an ITU-T standard speech codec.

Note that depending on law in your country, you may need a license for
distribution, any use, commercial use or even development.

WWW: http://www.penguin.cz/~utx/amr