GB/T 15485-1995 in English

《GB/T 15485-1995声学 语言清晰度指数的计算方法》由TC17（全国声学标准化技术委员会）归口，主管部门为中国科学院。
本标准描述了计算清晰度指数AI的方法和步骤并给出AI与音节清晰度之间的函数关系。本标准所述的计算方法的根据是男女成年正常发音人，以汉语普通话发音和男女成年正常听音人的平均结果。本方法中的数据不适用于儿童。

Scope

Because the speech intelligibility test is complicated and time-consuming, a computable physical measure that is highly correlated with speech intelligibility has been developed, which is like organizing a group of speakers and listeners to conduct speech perception tests to evaluate speech intelligibility . This physical measure is called the Articulation Index, or AI for short. AI is the effective ratio (part) of the normal speech signal available to a listener to obtain speech intelligibility under a given speech channel and noise condition, it is a weighted score, determined by the measured or estimated speech The spectrum and the effective masking spectrum of the noise present at the listener's ears allow computing the AI. This standard describes the method and steps of calculating the articulation index AI and gives the functional relationship between AI and syllable articulation. The calculation method described in this standard is based on the average results of male and female adult normal speakers, pronouncing in Mandarin Chinese and male and female adult normal listeners. The data in this method are not applicable to children. The method for calculating the intelligibility index AI described in this standard partly adopts the American National Standard ANSIS3.5-1969 "Calculation method for speech intelligibility index".