What is speaker authentication?.- Statistical approaches to detection, identification and verification.- Representations of speaker characteristics for authentication purposes.- Robust endpoint detection and feature extraction.- Statistical models for dynamic pattern recognition.- Fundamental approaches to speaker verification and identification.-Discriminative training.- Relation among discriminative training objectives.- Fast discriminative training algorithms for real application.- Fast and detection-based decoding for a large group of users.- Verbal information verification.- Sequential speaker authentication.- Sequential multi-modality biometric tests. Microphone array for speaker authentication and speech recognition.