| 摘要 |
<p>A method of analysis of characteristics of a telecommunications network by measuring properties of speech carried by a line under test comprises the steps of identifying a part of the speech signal which has a property independent of the talker, and detecting deviations from that property in the received signal, thereby identifying characteristics of the signal imposed by the system. The properties identified may be characteristic waveforms of speech phonemes, in which the fact that the human voice is only capable of making certain sounds is used to determine what deviations from those sounds have been imposed by the system. In an alternative arrangement identifying a part of the speech signal having a property which varies in a predetermined manner in relation to an absolute characteristic of the talker, and deriving the absolute characteristics therefrom. The absolute characteristic may be the absolute level of the voice, and the other property may be a talker-independent function of the absolute level, such as the spectral content of the unvoiced fricatives in the speech.</p> |
