公开(公告)号：US20210233509A1

公开(公告)日：2021-07-29

申请号：US16773259

申请日：2020-01-27

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Khosrow Lashkari ,  Narayan Kovvali ,  Seth Suppappola

IPC: G10K11/178 ,  H04S7/00 ,  H04R3/00

Abstract: A system performs pole-zero or IIR modeling and estimation of an inter-microphone transfer function between first and second microphones that output respective first and second microphone signals. The system includes a first adaptive FIR filter to which the first microphone signal is provided, a delay element that delays the second microphone signal by a predetermined delay amount, and a second adaptive FIR filter to which the delayed second microphone signal is provided. A first coefficient of the second adaptive FIR filter is constrained to a fixed non-zero value. The filters are jointly adapted to minimize an error signal that is a difference of the two filters outputs. The delay is small: approximately the acoustic propagation delay between the two microphones and is not determined by the environmental reverberation characteristics. The error signal may serve as a noise reference in a noise canceller, for implementing far-field beamforming with low delay.

公开(公告)号：US20190180014A1

公开(公告)日：2019-06-13

申请号：US15836677

申请日：2017-12-08

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Narayan Kovvali ,  Ying Li ,  Nima Yousefian Jazi ,  Seth Suppappola

IPC: G06F21/32 ,  G10L17/00 ,  G10L17/26 ,  H04R1/40

Abstract: The reliable differentiation of human and artificial talkers is important for many automatic speaker verification applications, such as in developing anti-spoofing countermeasures against replay attacks for voice biometric authentication. A multi-microphone approach may exploit small movements of human talkers to differentiate between a human talker and an artificial talker. One method of determining the presence or absence of talker movement includes monitoring the variation of the inter-mic frequency-dependent phase profile of the received microphone array data over a period of time. Using spatial information with spectral-based techniques for determining whether an audio source is a human or artificial talker may reduce the likelihood of success of spoofing attacks against a voice biometric authentication system. The anti-spoofing countermeasure may be used in electronic devices including smart home devices, cellular phones, tablets, and personal computers.

公开(公告)号：US20190096408A1

公开(公告)日：2019-03-28

申请号：US15714296

申请日：2017-09-25

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Ying Li ,  Ghassan Maalouli ,  Narayan Kovvali ,  Seth Suppappola

IPC: G10L17/00 ,  G10L15/22 ,  G10L17/06 ,  G10L25/21 ,  H04R1/40 ,  H04R3/00

Abstract: A change in the phase pattern of the inter-mic impulse response (IMIR), determined by a cross power spectral density, may be used to detect the appearance of a new talker or a dramatic movement of the current talker. For example, the phase of the IMIR is dependent on a location of the sound source relative to the microphone array. Any signal originating from a specific location has a specific phase pattern on the IMIR across the frequency domain. By comparing phase patterns of the current cross power spectral density with a recorded talker phase profile, a talker change can be detected. This detection can be used to control signal processing algorithms. For example, when talker change is detected, the step size of an adaptive filter can be increased to track the changes efficiently.