General In the process of generating speech and audio coding standards@ the following situations often happen: a) In many cases@ experimental results generated with different software tools may not be directly compared. b) Software tools used by different organizations may not perfectly conform to related ITU-T Recommendations@ which may delay ITU-T standardization processes. c) ITU-T Recommendations may leave scope for different implementations. d) New speech and audio coding standards are increasing in complexity@ leading to non-bitexact specifications; furthermore@ appropriate testing procedures to assure interoperability of different implementations are needed. The need for a common set of tools has been recognized in past ITU-T standardization activities of speech algorithms. As a consequence@ a library of portable@ interworkable and reliable software routines has been established.