This EN contains an electronic copy of the ANSI-C code for the GSM Enhanced Full Rate codec. The ANSI-C code is necessary for a bit exact implementation of the Enhanced Full Rate speech transcoder (GSM 06.60 (EN 301 245) [3])@ Voice Activity Detection (GSM 06.82 (EN 301 249) [7])@ comfort noise (GSM 06.62 (EN 301 247) [5])@ Discontinuous Transmission (GSM 06.81 (EN 301 248) [6]) and example solutions for substituting and muting of lost frames (GSM 06.61 (EN 301 246) [4]).