Patent ID: 8401204

Claim:
Method for the active reduction in a determined zone ( 22 ) of the energy of a sound signal (d k (n)), called propagated noise signal, generated in said zone ( 22 ) by a primary signal (x k (n)), called noise signal, said method comprising a transmission, by transmission means, of at least one counter-noise signal (y k (n)) comprising at least one first so-called feedback counter-noise signal (yfbk k (n)), counteracting said propagated noise signal (d k (n)), said method also comprising at least one iteration of the following operations: measurement, by measurement means arranged in said determined zone ( 22 ), of a so-called error signal (e k (n)), representing information on the effectiveness of the reduction of the energy of the propagated noise signal (d k (n)) in said zone ( 22 ); modelling, by at least one first filter (Ŝ kk (z)), of a direct acoustic path (S kk ), called secondary path, between said transmission means of the counter-noise signal (y k (n)) and said measurement means of said error signal (e k (n)); detection of at least one periodic component of said propagated noise signal (d k (n)) by analysis of a propagated noise signal (de k (n)) estimated from, on the one hand, the error signal (e k (n)) and, on the other hand, the feedback counter-noise signal (yfbk k (n)) processed by the first filter (Ŝ kk (z)), said detection providing said periodic component; and adjustment of said feedback counter-noise signal (yfbk k (n)) as a function of said detected periodic component, of said error signal (e k (n)) and of said modelled secondary path (Ŝ kk (z)).