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公开(公告)号：US09628040B2
公开(公告)日：2017-04-18
申请号：US14836006
申请日：2015-08-26
Inventor： John Paul Lesso , Toru Ido
CPC classification number: H03G3/3089 , H03F1/26 , H03F1/32 , H03F1/34 , H03F3/187 , H03F3/217 , H03F3/2171 , H03F3/2173 , H03F3/2175 , H03F2200/102 , H03F2200/339 , H03F2200/432 , H03G7/002 , H03G7/007
Abstract: This application relates to Class D amplifier circuits (200). A modulator (201) controls a Class D output stage (202) based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block (205), which may comprise an ADC (207), generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input (204) of a signal selector block (203). The input signal may be received at a second input (206) of the signal selector block (203). The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal. The error signal can be used to reduce distortion at high signal levels but is not used at low signal levels and so the noise floor at low signal levels does not depend on the component of the error block (205).
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公开(公告)号：US12288553B2
公开(公告)日：2025-04-29
申请号：US17261786
申请日：2019-07-31
Inventor： John Paul Lesso , César Alonso , Earl Corban Vickers
IPC: G10L15/20 , G06F21/32 , G10L15/22 , G10L21/0208 , G10L15/06
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.
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公开(公告)号：US12183333B2
公开(公告)日：2024-12-31
申请号：US17549528
申请日：2021-12-13
Inventor： John Paul Lesso , Robert James Hatfield
IPC: G10L15/20 , G10L15/08 , G10L15/28 , G10L17/24 , G10L21/0208
Abstract: A speech recognition system comprises: an input, for receiving an input signal from at least one microphone; a first buffer, for storing the input signal; a noise reduction block, for receiving the input signal and generating a noise reduced input signal; a speech recognition engine, for receiving either the input signal output from the first buffer or the noise reduced input signal from the noise reduction block; and a selection circuit for directing either the input signal output from the first buffer or the noise reduced input signal from the noise reduction block to the speech recognition engine.
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公开(公告)号：US12026241B2
公开(公告)日：2024-07-02
申请号：US17193430
申请日：2021-03-05
Inventor： John Paul Lesso
IPC: G06F21/32 , G06F3/16 , G10L17/00 , G10L17/08 , G10L17/24 , G10L17/26 , G10L25/06 , H04K1/00 , H04L9/40 , H04W12/06 , H04L9/32
CPC classification number: G06F21/32 , G06F3/167 , G10L17/00 , G10L17/08 , G10L17/24 , G10L17/26 , G10L25/06 , H04K1/00 , H04L63/0861 , H04L63/1466 , H04W12/06 , H04L9/3231
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.
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公开(公告)号：US11909362B2
公开(公告)日：2024-02-20
申请号：US17835326
申请日：2022-06-08
Inventor： John Paul Lesso
CPC classification number: H03F3/217 , H03F2200/129 , H03F2200/165
Abstract: This application relates to amplifier circuitry, in particular class-D amplifiers, operable in open-loop and closed-loop modes. An amplifier (300) has a forward signal path for receiving an input signal (SIN) and outputting an output signal (SOUT) and a feedback path operable to provide a feedback signal (SFB) from the output. A feedforward path provide a feedforward signal (SFF) from the input and a combiner (105) is operable to determine an error signal (ε) based on a difference between the feedback signal and the feedforward signal. The feedforward comprises a compensation module (201) configured to apply a controlled transfer function to the feedforward signal in the closed-loop mode of operation, such that an overall transfer function for the amplifier is substantially the same in the closed-loop mode of operation and the open-loop mode of operation.
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Patent Agency Ranking
公开(公告)号：US11880728B2
公开(公告)日：2024-01-23
申请号：US18296297
申请日：2023-04-05
Inventor： John Paul Lesso
CPC classification number: G06G7/48 , G06N3/065 , H02M1/0845 , H03M1/06 , H03M1/12
Abstract: This application relates to computing circuitry, and in particular to analogue computing circuitry suitable for neuromorphic computing. An analogue computation unit for processing data is supplied with a first voltage from a voltage regulator which is operable in a sequence of phases to cyclically regulate the first voltage. A controller is configured to control operation of the voltage regulator and/or the analogue computation unit, such that the analogue computation unit processes data during a plurality of compute periods that avoid times at which the voltage regulator undergoes a phase transition which is one of a predefined set of phase transitions between defined phases in said sequence of phases. This avoids performing computation operations during a phase transition of the voltage regulator that could result in a transient or disturbance in the first voltage, which could adversely affect the computing.
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公开(公告)号：US11799657B2
公开(公告)日：2023-10-24
申请号：US17253765
申请日：2018-10-01
Inventor： Michael Page , John Paul Lesso
IPC: H04L9/32
CPC classification number: H04L9/3231 , H04L9/3242 , H04L9/3252
Abstract: There is described a system and method for performing biometric authentication, preferably voice biometric authentication. The system has a host device such as a mobile phone and a coupled headset device. The headset device is arranged to receive audio, and to cryptographically protect the audio before transmission to the host device for verification and biometric authentication.
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公开(公告)号：US11755701B2
公开(公告)日：2023-09-12
申请号：US16029015
申请日：2018-07-06
Inventor： John Paul Lesso
CPC classification number: G06F21/32 , G10L17/12 , H04R5/033 , H04R1/1083 , H04R3/005 , H04R2410/00 , H04R2460/01 , H04R2460/13
Abstract: Methods, apparatus and systems for biometric authentication based on an audio signal are provided. The audio signal comprises a representation of a voice signal of a user conducted via at least part of a user's skeleton. Further embodiments may relate to biometric authentication based upon a combination of a bone-conducted audio signal, or a bone-conducted voice biometric process, with an air-conducted voice signal.
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公开(公告)号：US11748608B2
公开(公告)日：2023-09-05
申请号：US16844551
申请日：2020-04-09
Inventor： John Paul Lesso
Abstract: The present disclosure relates to a neural network system comprising: a data input configured to receive an input data signal and analog neural network circuitry having an input coupled with the data input. The analog neural network circuitry is operative to apply a weight to a signal received at its input to generate a weighted output signal. The neural network system further comprises compensation circuitry configured to apply a compensating term to the input data signal to compensate for error in the analog neural network circuitry.
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公开(公告)号：US11705135B2
公开(公告)日：2023-07-18
申请号：US17060339
申请日：2020-10-01
Inventor： John Paul Lesso
IPC: G10L17/26 , G10L17/00 , G10L25/51 , G10L25/03 , G01S7/539 , G01S15/88 , G01S7/52 , G01S15/58 , H04W88/02
CPC classification number: G10L17/26 , G01S7/52004 , G01S7/539 , G01S15/58 , G01S15/88 , G10L17/00 , G10L25/51 , G10L25/03 , H04W88/02
Abstract: Detecting a replay attack on a voice biometrics system comprises: receiving a speech signal from a voice source; generating and transmitting an ultrasound signal through a transducer of the device; detecting a reflection of the transmitted ultrasound signal; detecting Doppler shifts in the reflection of the generated ultrasound signal; and identifying whether the received speech signal is indicative of liveness of a speaker based on the detected Doppler shifts. The method further comprises: obtaining information about a position of the device; and adapting the generating and transmitting of the ultrasound signal based on the information about the position of the device.
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