Characteristics of a Low R Verification S

The performance of a speaker verification (SV) system is normally determined by the false reject (FRR) and false accept (FAR) rates as averages on a population of test speakers. However, information on the FRR distribution is required when estimating the portion of clients that will suffer from an unacceptably high reject rate. This paper studies this distribution in a population using a SV system operating in low reject mode. Two models of the distribution are proposed and compared with test data. An attempt is also made to tune the decision threshold in order to obtain a desired portion of clients having a reject rate lower than a specified value.