| 摘要 |
The headset includes an active noise control system, with an ANC microphone delivering a signal including an acoustic noise component. A digital signal processor DSP (50) comprises a feedback ANC branch (54) applying a filtering transfer function (HFB) to the signal picked up by the ANC microphone, and means (46) for mixing the signal of the feedback branch with an audio signal to be reproduced (M). The ANC microphone is an internal microphone (28) placed inside the acoustic cavity (22), and the feedback ANC filter (54) is one between a plurality of selectively switchable, pre-configured feedback ANC filter. The DSP (50) comprises means (62) for verifying whether current characteristics of the microphone signal fulfil or not a set of predetermined criteria, and for selecting one of the pre-configured feedback ANC filters as a function of the result of this verification. The filtering (HEQ) of an equalization branch (58) of the signal to be reproduced (M) is also modified as a function of the current selected feedback ANC filter. |
| 主权项 |
1. An audio headset, comprising two earphones (10) each including a transducer (18) for the sound reproduction of an audio signal to be reproduced, said transducer being housed in an ear acoustic cavity (22), said headset comprising an active noise control, ANC, system with:
an internal ANC microphone (28) placed inside the acoustic cavity (22), adapted to deliver a signal picked up in this cavity; and a digital signal processor, DSP, (50), comprising:
a closed-loop feedback branch (36), comprising a feedback ANC filter (54) adapted to apply a filtering transfer function (HFB) to the signal picked up by the ANC microphone, the feedback ANC filter (54) being one between a plurality of selectively switchable, preconfigured feedback ANC filters (F1, F2);means (62) for analysing in real time the signal picked up by the ANC microphone, adapted to verify if current characteristics of this signal, comprising values of energy of the signal (Rms1, Rms2 . . . ) in a plurality of frequency bands (Filter1, Filter2), fulfil a set of predetermined criteria;selection means (62), adapted to select one of the pre-configured feedback ANC filters (F1, F2) as a function of the result of the verification of the set of criteria performed by the analysis means; andmixing means (46), receiving as an input the signal delivered by the feedback branch at the output of the feedback ANC filter (54) as well as an audio signal to be reproduced (1W), and delivering as an output a signal adapted to pilot the transducer (18),characterized in that the DSP (50) further comprises:
an equalization branch, comprising an equalization filter (58) adapted to apply an equalization transfer function (HEQ) to said audio signal to be reproduced (A4) before application of the latter to the mixing means (60), the equalization means (58) being one between a plurality of selectively switchable, pre-configured equalization filters,and in that the selection means (62) are means adapted to select simultaneously:
i) one of the pre-configured feedback ANC filters (F1, F2) as a function of the result of the verification of said set of criteria; and ii) one of the pre-configured equalization filters, as a function of the current selected feedback ANC filter. |
