作为国防尖端研究工程局计划的一部分,研究话音在分组转换计算机网内传输,一种实时可变帧速率LPC声码器己在美国通信委员会信息科学研究所实现了。该声码器是在一浮点系统AP—102B阵列处理机上实现的。使用似然比门坎控制什么时候传输数据帧。该声码器的平均数据速率和语言质量取决于所使用的门坎值,但对于连续语言在数据速率低于2000bit/s时仍可获得满意的话音质量。 As part of its Defense Advanced Research Projects Agency (AIPA) project to study the transmission of voice over a packet-switched computer network, a real-time variable frame rate LPC vocoder has been implemented at the Institute of Information Science of the United States Communications Commission. The vocoder is implemented on a floating-point system AP-102B array processor. Use the likelihood ratio threshold to control when data frames are transmitted. The average data rate and speech quality of the vocoder depend on the threshold used, but satisfactory speech quality can be achieved for continuous speech at data rates below 2000 bit / s.