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(11) | EP 1 085 199 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Actively controlled induction noise using a quadrapole inlet |
(57) An active noise attenuation assembly for an air induction system of an internal combustion
engine is located in an air inlet duct leading to the engine. A fairing body is concentrically
mounted within the duct and defines an annular space with the duct through which air
travels. A loud speaker is mounted on the fairing body facing outwardly from the duct.
A controller generates an electrical signal amplified and phase shifted from a noise
field emanating from the engine. The signal is applied to the loudspeaker for broadcasting
a sound field phase shifted from the noise field for attenuating the noise field.
A transition housing having an outlet opening and an inlet opening forms a first pair
of opposing channels and a second pair of opposing channels. The housing mates to
the open end of the inlet duct. The first pair of opposing channels communicates with
the speaker and the second pair of opposing channels communicates with the annular
space. |