http://www.atc-labs.com/

http://www.voiceage.com/

http://www.compandent.com/

http://www.dvsinc.com/

http://www.scalatech.co.uk/

http://www.opus-codec.com/

http://dev.skype.com/silk

http://celt-codec.org/

http://codec2.org/

http://www.xiph.org/

http://www.rowetel.com

http://www.adaptivedigital.com/

http://www.fraunhofer.de/en.html