-
公开(公告)号：US11042616B2
公开(公告)日：2021-06-22
申请号：US16017072
申请日：2018-06-25
Inventor： John Paul Lesso
IPC: G06F21/32 , G10L17/26 , G06F3/16 , G10L17/24 , H04L29/06 , G10L17/08 , H04K1/00 , G10L25/06 , H04W12/06 , G10L17/00 , H04L9/32
Abstract: Detecting a replay attack on a voice biometrics system comprises receiving a speech signal; forming an autocorrelation of at least a part of the speech signal; and identifying that the received speech signal may result from a replay attack based on said autocorrelation. Identifying that the received speech signal may result from a replay attack may be achieved by: comparing the autocorrelation with a reference value; and identifying that the received speech signal may result from a replay attack based on a result of the comparison of the autocorrelation with the reference value, or by: supplying the autocorrelation to a neural network trained to distinguish autocorrelations formed from speech signals resulting from replay attacks from autocorrelations formed from speech signals not resulting from replay attacks.
-
公开(公告)号：US11037574B2
公开(公告)日：2021-06-15
申请号：US16122033
申请日：2018-09-05
Inventor： John Paul Lesso
Abstract: A method of speaker recognition comprises: receiving an audio signal comprising speech; performing a biometric process on a first part of the audio signal, wherein the first part of the audio signal extends over a first time period; obtaining a speaker recognition score from the biometric process for the first part of the audio signal; performing a biometric process on a plurality of second parts of the audio signal, wherein the second parts of the audio signal are successive sections of the first part of the audio signal, and wherein each second part of the audio signal extends over a second time period and the second time period is shorter than the first time period; obtaining a respective speaker recognition score from the biometric process for each second part of the audio signal; and determining whether there has been a speaker change based on the respective speaker recognition scores for successive second parts of the audio signal.
-
公开(公告)号：US10984269B2
公开(公告)日：2021-04-20
申请号：US16157843
申请日：2018-10-11
Inventor： John Paul Lesso
IPC: G06K9/00 , G10L17/00 , G01S15/88 , G01S7/539 , G01S15/58 , G01S7/52 , G06K9/22 , G10L25/51 , G10L25/03
Abstract: Detecting liveness of a speaker comprises: generating an ultrasound signal; receiving an audio signal comprising a reflection of the ultrasound signal; using the received audio signal comprising the reflection of the ultrasound signal to detect the liveness of a speaker; monitoring ambient ultrasound noise; and adjusting the operation of a system receiving the audio signal, based on a level of the reflected ultrasound and the monitored ambient ultrasound noise. The method can be used in a voice biometrics system, in which case detecting the liveness of a speaker comprises determining whether a received speech signal may be a product of a replay attack. The operation of the voice biometrics system may be adjusted based on a level of the reflected ultrasound and the monitored ambient ultrasound noise.
-
公开(公告)号：US10915614B2
公开(公告)日：2021-02-09
申请号：US16118950
申请日：2018-08-31
Inventor： John Paul Lesso
Abstract: A method for authenticating a user of an electronic device is disclosed. The method comprises: responsive to detection of a trigger event indicative of a user interaction with the electronic device, generating an audio probe signal to play through an audio transducer of the electronic device; receiving a first audio signal comprising a response of the user's ear to the audio probe signal; receiving a second audio signal comprising speech of the user; and applying an ear biometric algorithm to the first audio signal and a voice biometric algorithm to the second audio signal to authenticate the user as an authorised user.
-
公开(公告)号：US10692490B2
公开(公告)日：2020-06-23
申请号：US16050593
申请日：2018-07-31
Inventor： John Paul Lesso , César Alonso
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.
-
Patent Agency Ranking
公开(公告)号：US10674253B2
公开(公告)日：2020-06-02
申请号：US15935428
申请日：2018-03-26
Inventor： John Paul Lesso , Emmanuel Philippe Christian Hardy
Abstract: This application describes a noise reduction apparatus (800) for a microphone device (100) having an acoustic port (110). The apparatus has a spectrum peak detect block (301) for receiving a microphone signal (SMIC) and determining, from the microphone signal, at least one characteristic of a resonance peak (202) associated with the acoustic port of the microphone. The at least one characteristic may comprise a resonance frequency (fH) and/or quality factor (QH). A noise reduction block (801) is configured to process the microphone signal based on the resonance characteristic so as to reduce noise in the processed microphone signal due to said resonance. The noise reduction block may apply a function which is the inverse of the determined resonance characteristic.
-
公开(公告)号：US10567896B2
公开(公告)日：2020-02-18
申请号：US16275726
申请日：2019-02-14
Inventor： John Paul Lesso , Emmanuel Philippe Christian Hardy
Abstract: This application describes an apparatus (300) for monitoring for blockage of an acoustic (110) port of a microphone device (100). The apparatus has a spectrum peak detect block (301) for receiving a microphone signal (SMIC) and determining, from the microphone signal, a resonance frequency (fH) and a quality factor (QH) of a resonance (202) associated with the acoustic port. A condition monitoring block (302) is configured to determine any change in resonance frequency and quality factor and to determine a blockage status for the microphone based on said detect changes. The condition monitoring block identifies a change in blockage status if there is a change in quality factor.
-
公开(公告)号：US10375493B2
公开(公告)日：2019-08-06
申请号：US16009638
申请日：2018-06-15
Inventor： John Paul Lesso , Yanto Suryono
IPC: H04R29/00 , H04R3/04 , G10L19/12 , G01R31/3167 , G10L19/04
Abstract: An audio system receives an input signal and, if the input signal has a sparse representation in the frequency domain, comprising components at at least one frequency of interest, the input signal is filtered in at least one band pass filter, such that only components at the or each frequency of interest are passed to an output. The operation is able in some case to analyze the input signal to determine whether the input signal has a sparse representation in the frequency domain.
-
公开(公告)号：US10263633B2
公开(公告)日：2019-04-16
申请号：US15991619
申请日：2018-05-29
Inventor： John Paul Lesso , David Paul Singleton
Abstract: This application relates time-encoding modulators such as may be used as part of analogue-to-digital conversion. A time-encoding modulator (100) receives an analogue input signal (SIN) at an input node (102) and outputs a corresponding time-encoded signal (SOUT) at an output node (103). A hysteretic comparator (101) has a first comparator input connected to the input node and a comparator output connected to the output node. A feedback path extends between the output node and a second comparator input of the hysteretic comparator; with a filter arrangement (104) arranged to apply filtering to the feedback path. The hysteretic comparator (101) compares the input signal (SIN) to the feedback signal (SFB) with hysteresis. This provides a pulse-width modulated output signal (SOUT) where the duty cycle encodes the input signal (SIN).
-
公开(公告)号：US10003344B2
公开(公告)日：2018-06-19
申请号：US15009405
申请日：2016-01-28
Inventor： John Paul Lesso
CPC classification number: H03L7/099 , G06F3/162 , H03G5/00 , H03G5/005 , H03L7/08 , H03L7/087 , H03L7/14 , H03L7/18 , H03L2207/50
Abstract: A clock generator receives first and second clock signals, and input representing a desired frequency ratio. A comparison is made between frequencies of an output clock signal and the first clock signal, and a first error signal represents the difference between the desired frequency ratio and this comparison result. The first error signal is filtered. A comparison is made between frequencies of the output clock signal and the second clock signal, and a second error signal represents the difference between the filtered first error signal and this comparison result. The second error signal is filtered. A numerically controlled oscillator receives the filtered second error signal and generates an output clock signal. As a result, the output clock signal has the jitter characteristics of the first input clock signal over a useful range of jitter frequencies and the frequency accuracy of the second input clock signal.
-
-
-
-
-
-
-
-
-
Search Results
160
records
(took 0.061 seconds)
