Adaptive active noise cancellation apparatus and audio playback system using the same
AssigneeAiroha Technology Corp.
InventorsChao-Ling HSU, Li-Wen CHI
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Abstract
The invention relates to an adaptive active noise cancellation apparatus and an audio playback system using the same. The adaptive active noise cancellation apparatus shapes an error signal and a noise signal according to a shape of an ideal noise. After that, the shaped noise signal and the shaped error signal are sent into a parameter adjusting unit to perform an adaptive parameter adjustment. Thus, the adaptive noise filter unit is not only can adaptively suppress noise and minimize the error signal, but also can suppress specific frequencies that are sensitive to the human ear.
Claims28
An adaptive active noise cancellation apparatus, adapted for an audio playback system, wherein the audio playback system is for outputting an anti-phase noise audio signal according to an anti-phase noise signal, wherein the audio playback system comprises an error microphone for receiving an environmental noise and the anti-phase noise audio signal to generate an error signal, wherein the adaptive active noise cancellation apparatus comprises:
- an automatic noise shaping circuit receiving the error signal, shaping an interference signal to a shaped interference signal and shaping the error signal to a shaped error signal according to a preset noise shape, and outputting the shaped interference signal and the shaped error signal;
- an adaptive active noise filtering unit receiving the interference signal, outputting the anti-phase noise signal for generating the anti-phase noise audio signal;
- a first transmission channel simulation unit receiving the shaped interference signal for generating a simulated shaped interference signal according to a channel transfer function;
- and
- a coefficient adjustment unit receiving the simulated shaped interference signal and the shaped error signal, and adjusting a filter coefficient of the adaptive active noise filtering unit by an adaptive algorithm according to the simulated shaped interference signal and the shaped error signal.
An audio playback system, outputting an anti-phase noise audio signal according to an anti-phase noise signal, wherein the audio playback system comprises:
- an error microphone receiving an environmental noise and the anti-phase noise audio signal, to generate an error signal;
- and
- an adaptive active noise cancellation apparatus, comprising:
- an automatic noise shaping circuit receiving the error signal, shaping an interference signal to a shaped interference signal and the error signal to a shaped error signal according to a preset noise shape and outputting the shaped interference signal and the shaped error signal;
- an adaptive active noise filtering unit receiving the interference signal, outputting the anti-phase noise signal for generating the anti-phase noise audio signal;
- a first transmission channel simulation unit receiving the shaped interference signal for generating a simulated shaped interference signal according to a channel transfer function;
- and
- a coefficient adjustment unit receiving the simulated shaped interference signal and the shaped error signal, adjusting a filter coefficient of the adaptive active noise filtering unit by an adaptive algorithm according to the simulated shaped interference signal and the shaped error signal.
Dependencies are inferred from the claim text.