Speaker verification with sequential decision on a speaker specific vocabulary

The speaker veri:fication technique was evaluated with over 5000 words from 13 speakers employing telephone handsets and accessing a verification simulation over the switched telephone network. A total of 977 verifi.cation attempts and 21421 impersonation attempts was simulated. A false acceptance rate of 0.1% was attained after an average of 1.2 words input. The same conditions gave rise to a false rejection rate of 0.5% after an average of 2 words input. The above results are significantly degraded if the prompted words are selected at random from the entire training vocabulary and not according to their power to discriminate among the enrolled speakers.