METHOD FOR DETECTING AN AUDIO ADVERSARIAL ATTACK WITH RESPECT TO A VOICE INPUT PROCESSED BY AN AUTOMATIC SPEECH RECOGNITION SYSTEM, CORRESPONDING DEVICE, COMPUTER PROGRAM PRODUCT AND COMPUTER-READABLE CARRIER MEDIUM

摘要

The disclosure relates to a method and device for detecting an audio adversarial attack with respect to a voice input (VI) processed by an automatic speech recognition system (ASR). The method includes: obtaining (11) an input audio signal (IAS) associated with the voice input; obtaining (12) a transcript (T) resulting from the processing, by the automatic speech recognition system, of the input audio signal; converting (13) the transcript (T) into a synthesized audio signal (SAS); extracting (15, 15'), at a sampling time interval, at least one acoustic feature of a same type, respectively from the input audio signal and from the synthesized audio signal, delivering a first sequence of features vectors (sFV1) associated with the input audio signal and a second sequence of features vectors (sFV2) associated with the synthesized audio signal; converting (16, 16') the acoustic features of the first sequence of features vectors and the acoustic features of the second sequence of features vectors to corresponding acoustic features associated with a target reference voice (RV), respectively delivering a first sequence of converted features vectors (sCFV1) and a second sequence of converted features vectors (sCFV2); computing (17) a dynamic time warping distance (D) between the first sequence of converted features vectors and the second sequence of converted features vectors; and delivering (18) a piece of data representative of a detection of an audio adversarial attack, as a function of a result of a comparison between the dynamic time warping distance and a predetermined threshold.