Nanyang Technological University

Other

Hui Lan

Ming Zhang

Zhuliang Yu

Wee Ser

Susanto Rahardja

The present invention provides an adaptive directional microphone system for enhancing an acoustic signal from a second direction and for reducing an acoustic signal from at least a first direction different from the second direction, the system comprising:

Post-processing scheme for adaptive directional microphone system with noise/interference suppression

An adaptive noise canceling system for extracting a desired signal, comprising an adaptive noise cancellation filtering circuit for suppressing noise from a first input signal using a second input signal as a reference signal, and generating an output filtered signal representing the desired signal; and an adaptive noise cancellation controller for receiving the first and second input signals and the output filtered signal, and generating an output control signal for controlling coefficients of at least one adaptive filter of the adaptive noise cancellation filtering circuit, comprising a silence detector unit for detecting whether an acoustical signal is present in the input signals and the output filtered signal, and generating a first output signal which indicates whether the acoustical signal is present; a signal detector unit for detecting whether the desired signal is present in the input signals and the output filtered signal, and generating a second output signal which indicates whether the desired signal is present; and an adaptive noise cancellation filter (ANCF) controller unit for receiving the first and second output signal to determine the characteristic of the input signals, and generating the output control signal which represents an updated coefficient parameter for updating the coefficients of the at least one adaptive filter of the adaptive noise cancellation filtering circuit.

Adaptive control system for noise cancellation

A system with an accompanying method is provided to improve the signal-to-noise ratio (SNR) of noisy speech by suppressing acoustic background noise. The background noise consists of narrow band noise from rotating machine, audio signals from stereo-loudspeakers of audio entertainment device, and other ambient noise. In this system/apparatus, a microphone senses the speech intermingled with the background noise, and another microphone senses the noisy background. In addition, a measurement sensor is used to measure RPM (revolutions-per-minutes) of the rotating machine and two wires are used to acquire audio signals from the stereo-loudspeakers of the audio entertainment device. Furthermore, to provide better suppression performance for the acoustic audio signals, the characteristics of these loudspeakers are used to compensate for the distortion caused by the loudspeakers. Adaptive comb filters and adaptive FIR filters are applied to estimate the ambient noise and suppress the background noise. After processing, the system outputs the enhanced speech signal with higher SNR.

System for noise suppression, transceiver and method for noise suppression

An active noise control system is provided to specify an input transducer, an error transducer, an output transducer and an active noise controller for generating an anti-phase canceling acoustic signal to attenuate an input noise and to output a reduced noise. The active noise control system also performs on-line secondary path modeling. For this purpose the active noise control system comprises, in addition to known systems, a secondary path change detection circuitry (), a signal distinguishing circuitry () and an auxiliary noise control circuitry (), all of them being used to model said secondary path.

Active noise control system with on-line secondary path modeling

A known cross-talk adaptive noise cancellation apparatus uses two adaptive filters for suppressing the correlated noise in the main signal, which contains wanted voice and unwanted noise, by a reference signal, which contains unwanted noise and wanted voice via cross-talking. A noise canceler is provided in the present invention including some additional parts, such as a voice detection circuitry and a step size decision circuitry. The voice detection circuitry detects whether the wanted voice exists. The step size decision circuitry decides what the step sizes are used for the next update of the two adaptive filters.

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Singapore, Singapore

Hui Lan