In an earlier report [C. A. McGonegalet al., J. Acoust. Soc. Am.62, S4(A) (Fall 1977).] the effects of several transmission systems on speaker verification by human listeners were investigated. There it was shown that the transmission system played a significant role in the speaker verification process. In this talk we show the effects of the transmission system on an existing automatic speaker verification system [A. E. Rosenberg, Bell Systems Technical Journal55, 723–744 (1976)] in which the measured features are pitch and gain as a function of time for a specified utterance. There were ten male and ten female customers and 40 male and 40 female imposters in this experiment. All utterances were recorded using a conventional telephone connection. Post processing included ADPCM coding and LPC vocoding. Preliminary results indicate that, on the average, the transmission system affects the verification accuracy, especially when the reference and test utterances are subjected to different transmission conditions.