Spectral shifting of speaker-specific information for narrow band telephonic speaker recognition

Speech-based authentication system can perform remote authentication over telephone channels. However, telephone channels are restricted to a bandwidth of ~0-4 kHz while studies on the distribution of speaker-specific information in the speech spectrum strongly suggests that useful speaker-specific information is present above 4 kHz. A method to shift a part of this speaker-specific information above 4 kHz into the telephone bandwidth in place of less speaker-specific information originally present below 4 kHz is proposed. Speaker recognition experiments conducted using the proposed method leads to ~18.5% relative improvement on equal error rate when compared to a system using the conventional telephone band speech, as evaluated on the Intelligence Advanced Research Projects Activity (IARPA) Babel Program Tamil language collection.