Abstract: A method for use in a biometric process, comprising: with a headset in a known acoustic environment, applying an acoustic stimulus at a first transducer of the headset; receiving a response signal at a second transducer of the headset, the response signal comprising a component of the acoustic stimulus reflected at an obstacle in the acoustic path of the first transducer; determining a condition of the headset based on the response signal; and performing the biometric process based on the determined condition.

Abstract: This application relates to methods and apparatus for temperature monitoring for integrated circuits, and in particular to temperature monitoring using a locked-loop circuits, e.g. FLLs, PLLs or DLLs. According to embodiments a locked-loop circuit (200, 600) includes a controlled signal timing module (201, 601), wherein the timing properties of an output signal (SOUT, SFB) are dependent on a value of a control signal and on temperature. A controller (201, 601) compares a feedback signal (SFB) output from the timing module to a reference signal (SREF) and generates a control signal (SC) to maintain a desired timing relationship. A temperature monitor (202) monitors temperature based on the value of the control signal. For FLLs and PLLs the signal timing module may be a controlled oscillator (201).

Abstract: A method of performing speech recognition, comprises, at a first device: receiving an audio signal representing speech; performing a first data integrity check operation on the received audio signal; performing a speaker recognition process on the received audio signal; forwarding the received audio signal to a second device, wherein the second device comprises a speech recognition function; and forwarding an output of the first data integrity check operation to the second device.

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.

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.

Abstract: Detecting a replay attack on a voice biometrics system comprises: receiving a speech signal; generating an ultrasound signal; detecting a reflection of the generated ultrasound signal; detecting Doppler shifts in the reflection of the generated ultrasound signal; and identifying whether the received speech signal is indicative of the liveness of a speaker based on the detected Doppler shifts. Identifying whether the received speech signal is indicative of liveness based on the detected Doppler shifts comprises determining whether the detected Doppler shifts correspond to a speech articulation rate.

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.

Abstract: The present invention relates to methods, apparatus and systems for authentication of a user based on ear biometric data, and voice biometric data or other authentication data. The ear biometric data may be combined with voice biometric data or with a security question and response.

Abstract: The present disclosure relates to an artificial neural network (ANN) computing system comprising: a buffer configured to store data indicative of input data received from an input device; an inference engine operative to process data from the buffer to generate an interest metric for the input data; and a controller. The controller is operative to control a mode of operation of the inference engine according to the interest metric for the input data.

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 (?) 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.

Abstract: This application relates an activity detector (100) for detecting signal activity in an input audio signal (SIN), such as may be used for always-on speech detection. The activity detector has a first time-encoding modulator (TEM) 101 including a first hysteretic comparator (201) for generating a PWM (pulse-width modulation) signal based on the input audio signal. A second TEM (103) having a second hysteretic comparator (401) is arranged to receive a reference voltage (VMID) and generate a clock signal (SCLK). A time-decoding converter (102) receives the clock signal and generates count values of a number of cycles of the clock signal in periods defined by the PWM signal. An activity monitor (104) is responsive to a count signal (SCT) from the TDC 102 to determine whether the input audio signal comprises signal activity above a defined threshold.

Abstract: Embodiments of the disclosure provide a mechanism for performing a biometric algorithm on ear biometric data acquired from a user. The mechanism may be used for biometric authentication, or in-ear detect, for example. In one embodiment, a method is provided in which a quality metric of an input signal to a transducer and/or a signal on a return path from the transducer is monitored. One or more steps of a biometric process, comprising monitoring of a parameter related to an admittance of the transducer, comparison of the parameter to a stored profile for an authorised user, generation of a score based on the comparison, comparison of the score to one or more threshold values, and initiation of one or more actions, may be performed responsive to the quality metric meeting one or more criteria.

Abstract: This application describes methods and apparatus for generating a prompt to be presented to a user for the user to vocalise as part of speaker recognition. An apparatus according to an embodiment has a selector for selecting at least one vocal prompt element to form at least part of said prompt from a predetermined set of a plurality of vocal prompt elements. The selector is configured to select the vocal prompt element based, at least partly, on an indication of the operating conditions for the biometric speaker recognition, for example background noise. The prompt is selected to be one which will provide a good likelihood of discrimination between users when vocalised and used for speaker recognition in the current operating conditions. The prompt may be issued as part of a verification process for an existing user or an enrolment process for an enrolling user.

Abstract: Embodiments of the disclosure include methods, apparatus and computer programs for detecting the proximity of an ear to an audio device. In one embodiment, the disclosure provides a system for detecting the presence of an ear in proximity to an audio device. The system comprises: an input for obtaining a data signal from the environment of the audio device; and an ear biometric authentication module configured to: compare one or more ear biometric features, extracted from the data signal, to an ear biometric template; and generate a first output indicative of the presence or absence of any ear in proximity to the audio device based on the comparison of the one or more extracted ear biometric features to the ear biometric template.

Abstract: This application relates to methods and apparatus for temperature monitoring for integrated circuits, and in particular to temperature monitoring using a locked-loop circuits, e.g. FLLs, PLLs or DLLs. According to embodiments a locked-loop circuit (200, 600) includes a controlled signal timing module (201, 601), wherein the timing properties of an output signal (SOUT, SFB) are dependent on a value of a control signal and on temperature. A controller (201, 601) compares a feedback signal (SFB) output from the timing module to a reference signal (SREF) and generates a control signal (SC) to maintain a desired timing relationship. A temperature monitor (202) monitors temperature based on the value of the control signal. For FLLs and PLLs the signal timing module may be a controlled oscillator (201).

Abstract: Audio circuitry, comprising: a speaker driver operable to drive a speaker based on a speaker signal; a current monitoring unit operable to monitor a speaker current flowing through the speaker and generate a monitor signal indicative of that current; and a microphone signal generator operable, when external sound is incident on the speaker, to generate a microphone signal representative of the external sound based on the monitor signal and the speaker signal.

Abstract: A method of performing speech recognition, comprises, at a first device: receiving an audio signal representing speech; performing a first data integrity check operation on the received audio signal; performing a speaker recognition process on the received audio signal; forwarding the received audio signal to a second device, wherein the second device comprises a speech recognition function; and forwarding an output of the first data integrity check operation to the second device.

Abstract: Driver circuitry is disclosed for driving an electroacoustic transducer to provide an output comprising both ultrasonic and audio signal components. The driver circuitry comprises an adjustment module configured to reduce the level of said ultrasonic component signal in response to an increase in an operational variable indicative of a level of said audio signal component, while also increasing the pulse duration, duty cycle, repetition frequency or frequency span or bandwidth of the ultrasonic component.

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.

Abstract: In order to detect a replay attack in a speaker recognition system, at least one feature is identified in a detected magnetic field. It is then determined whether the at least one identified feature of the detected magnetic field is indicative of playback of speech through a loudspeaker. If so, it is determined that a replay attack may have taken place.