ETSI ES 201 377-2-2009 语音和多媒体传输质量(STQ).语音传输质量的规范和测量.第2部分:包括终端在内的口-耳语音传输质量(版本1.4.1)
Speech and multimedia Transmission Quality (STQ); Specification and measurement of speech transmission quality; Part 2: Mouth-to-ear speech transmission quality including terminals (V1.4.1)