Exploring linear prediction residual signal for developing countermeasures to playback attacks

Playback attack is an approach for acquiring the unauthorized access to the automatic speaker verification (SV) system by using targets' pre-recorded speech samples. It is now a widely acknowledged fact that state-of-the-art SV systems are quite vulnerable to playback attacks, and developing countermeasures are in progress. In that direction most of the attempts try to capture the trace of the playback device characteristics by using spectral related information, that remain almost intact in playback signals, resulting less improvements in false acceptance rate. In this work we explore the use of linear prediction (LP) residual signal to counter the playback attacks. We observed that, as compared to spectral related vocal-tract features, the parametric representation of the LP residual signal shows relatively more robustness against playback attacks. In future, we aim to model the LP residual signal explicitly and develop countermeasures to playback attacks.