公开(公告)号：US20220157334A1

公开(公告)日：2022-05-19

申请号：US16953104

申请日：2020-11-19

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： César ALONSO

IPC: G10L25/93 ,  G10L25/18 ,  G10L25/21 ,  G10L15/22 ,  G10L25/78

Abstract: A method of detecting live speech comprises: receiving a signal containing speech; forming a framed version of the received signal that comprises a plurality of frames; forming a first subset of the plurality of frames, wherein each frame of the first subset contains a signal that contains voiced speech; forming a second subset of the plurality of frames, wherein each frame of the second subset contains a signal that contains unvoiced speech; forming a first frame that is representative of a sum of a plurality of frames of the first subset; forming a second frame that is representative of a sum of a plurality of frames of the second subset; performing a time-frequency transformation operation on the first frame, to form an average voiced frequency spectrum; performing a time-frequency transformation operation on the second frame, to form an average unvoiced frequency spectrum; obtaining one or more voiced features from the voiced frequency spectrum; and obtaining one or more unvoiced features from the unvoiced frequency spectrum. Based on the one or more voiced features and the one or more unvoiced features, a determination is made whether the speech is live speech, or not.

公开(公告)号：US20190005963A1

公开(公告)日：2019-01-03

申请号：US16020406

申请日：2018-06-27

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： César ALONSO ,  John Paul LESSO

IPC: G10L17/22 ,  H04R1/40 ,  G06F21/55

Abstract: A method of detecting a replay attack on a voice biometrics system comprises: receiving an audio signal representing speech; detecting a magnetic field; determining if there is a correlation between the audio signal and the magnetic field; and if there is a correlation between the audio signal and the magnetic field, determining that the audio signal may result from a replay attack.

公开(公告)号：US20200043484A1

公开(公告)日：2020-02-06

申请号：US16050593

申请日：2018-07-31

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul LESSO ,  César ALONSO

IPC: G10L15/20 ,  G10L15/22 ,  G06F21/32 ,  G10L21/0208

Abstract: A method of detecting a replay attack comprises: receiving an audio signal representing speech; identifying speech content present in at least a portion of the audio signal; obtaining information about a frequency spectrum of each portion of the audio signal for which speech content is identified; and, for each portion of the audio signal for which speech content is identified: retrieving information about an expected frequency spectrum of the audio signal; comparing the frequency spectrum of portions of the audio signal for which speech content is identified with the respective expected frequency spectrum; and determining that the audio signal may result from a replay attack if a measure of a difference between the frequency spectrum of the portions of the audio signal for which speech content is identified and the respective expected frequency spectrum exceeds a threshold level.

公开(公告)号：US20210256971A1

公开(公告)日：2021-08-19

申请号：US17261786

申请日：2019-07-31

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul LESSO ,  César ALONSO ,  Earl Corban VICKERS

IPC: G10L15/20 ,  G06F21/32 ,  G10L15/22 ,  G10L21/0208

Abstract: A method of detecting a replay attack comprises: receiving an audio signal representing speech; identifying speech content present in at least a portion of the audio signal; obtaining information about a frequency spectrum of each portion of the audio signal for which speech content is identified; and, for each portion of the audio signal for which speech content is identified: retrieving information about an expected frequency spectrum of the audio signal; comparing the frequency spectrum of portions of the audio signal for which speech content is identified with the respective expected frequency spectrum; and determining that the audio signal may result from a replay attack if a measure of a difference between the frequency spectrum of the portions of the audio signal for which speech content is identified and the respective expected frequency spectrum exceeds a threshold level.

公开(公告)号：US20200265834A1

公开(公告)日：2020-08-20

申请号：US16869176

申请日：2020-05-07

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul LESSO ,  César ALONSO

IPC: G10L15/20 ,  G10L21/0208 ,  G10L15/22 ,  G06F21/32

Abstract: A method of detecting a replay attack comprises: receiving an audio signal representing speech; identifying speech content present in at least a portion of the audio signal; obtaining information about a frequency spectrum of each portion of the audio signal for which speech content is identified; and, for each portion of the audio signal for which speech content is identified: retrieving information about an expected frequency spectrum of the audio signal; comparing the frequency spectrum of portions of the audio signal for which speech content is identified with the respective expected frequency spectrum; and determining that the audio signal may result from a replay attack if a measure of a difference between the frequency spectrum of the portions of the audio signal for which speech content is identified and the respective expected frequency spectrum exceeds a threshold level.