A method for detecting an audio adversarial attack with respect to a voice input (VI) processed by an automatic speech recognition system (ASR), the method being implemented by a detection device connected to the automatic speech recognition system, wherein the method comprises: obtaining an input audio signal (IAS) associated with the voice input; obtaining a transcript (T) resulting from the processing, by the automatic speech recognition system (ASR), of the input audio signal (IAS); converting the transcript (T) into a synthesized audio signal (SAS) associated with a target text-to-speech voice (TV); extracting , 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 the acoustic features of the first sequence of features vectors (sFV1) and the acoustic features of the second sequence of features vectors (sFV2) to corresponding acoustic features associated with a target reference voice (RV), respectively delivering a first sequence of converted features vectors (sCFV1) associated with the input audio signal and a second sequence of converted features vectors (sCFV2) associated with the synthesized audio signal; computing a dynamic time warping distance (D) between the first sequence of converted features vectors (sCFV1) and the second sequence of converted features vectors (sCFV2); and delivering 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 (D) and a predetermined threshold. obtaining an input audio signal (IAS) associated with the voice input; obtaining a transcript (T) resulting from the processing, by the automatic speech recognition system (ASR), of the input audio signal (IAS); converting the transcript (T) into a synthesized audio signal (SAS) associated with a target text-to-speech voice (TV); extracting , 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 the acoustic features of the first sequence of features vectors (sFV1) and the acoustic features of the second sequence of features vectors (sFV2) to corresponding acoustic features associated with a target reference voice (RV), respectively delivering a first sequence of converted features vectors (sCFV1) associated with the input audio signal and a second sequence of converted features vectors (sCFV2) associated with the synthesized audio signal; computing a dynamic time warping distance (D) between the first sequence of converted features vectors (sCFV1) and the second sequence of converted features vectors (sCFV2); and delivering 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 (D) and a predetermined threshold. <EOS>