Parrot

Parrot Drones

Phong Hua

Benoit Pochon

Vu Hoang Co Thuy

Pierre Guiu

The headset includes an active noise control, with an internal ANC microphone () placed inside the acoustic cavity () and delivering a signal including an acoustic noise component. A digital signal processor DSP () comprises a feedback ANC branch () applying a filtering transfer function (, H) to the signal delivered by the ANC microphone, and a mixer () for mixing the signal of the feedback branch with an audio signal to be reproduced (M). The headset comprises a movement sensor () mounted on one of the earphones. The DSP comprises an anti-saturation module () for analyzing concurrently i) the signal delivered by the internal microphone () and ii) the signal delivered by the movement sensor (), and verifying whether current characteristics of these signals fulfill or not a set of predetermined criteria. Upstream from the feedback ANC filter (), an anti-saturation filter (, H) is selectively switched as a function of the result of this verification. The filtering of an equalization branch (, H) of the signal to be reproduced (M) is also modified by a similar anti-saturation filter (, H).

ANC noise active control audio headset with prevention of the effects of a saturation of the feedback microphone signal

The headset comprises two earpieces each having a transducer for playing back the sound of an audio signal and received in an acoustic cavity defined by a shell having an ear-surrounding cushion. The active noise control comprises, in parallel, a feedforward bandpass filter receiving the signal from an external microphone, a feedback bandpass filter receiving as input an error signal delivered by an internal microphone, and a stabilizer bandpass filter locally increasing the phase of the transfer function of the feedback filter in an instability zone, in particular a waterbed effect zone around 1 kHz. A summing circuit delivers a weighting linear combination of the signal delivered by these filters together with the audio signal to be played back. Control is non-adaptive, with the parameters of the filters being static.

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Paris, France

Phong Hua