Automatic speaker recognition using vocoded speech

Automatic speaker recognition (ASR) offers potential benefit for numerous applications, including identification of users of communication channels such as the telephone and channels using processed or vocoded speech. Currently the listener must subjectively determine whether the person on the other end of the line is who he or she claims to be. However, when the speech is processed, recognition of voices can be very difficult for human listeners. A series of tests was conducted to evaluate the feasibility of automatic speaker recognition with processed or vocoded speech. The analog outputs of six different voice processors were used as input to a real-time ASR system. Recognition accuracy results for the processed speech were 70% to 95% using a 2500 Hz bandwidth input filter, and 75% to 95% using a 4000 Hz input filter. These results indicate that ASR using vocoded speech is definitely feasible, though further research is needed to determine which speech parameters are best suited for use with each voice processor.