Patent ID: 7963362

Claim:
An aircraft nacelle that comprises: a duct that extends from an air intake to a rear outlet, said duct being coated by an acoustic panel that comprises a reflective layer ( 28 ); at least one alveolar structure ( 30 ); and an acoustically resistive structure ( 32 ) that forms an aerodynamic surface of said duct on the surface of which at least on, acoustic wave propagates along an axis of propagation ( 24 ), wherein at least one of the characteristics of the acoustic panel influences the impedance of said panel that varies along the axis of propagation ( 24 ) of said at least one acoustic wave, and wherein at least one of the characteristics of the acoustic panel influencing the impedance is constant in a zone A disposed at the level of the air intake and has a value V 1 , is constant in a zone C disposed at the level of the outlet and has a value V 2 and varies within a zone B that separates the zones A and C passing continuously from the value V 1 to the value V 2 .