| 摘要 |
A fume extractor hood (1) is disclosed, comprising a box (2) with a motor-fan assembly and a muffler module (4) comprising a bearing frame defining an air extraction conduit (C) with axis (A), an active noise suppression system comprising at least one electro-acoustic transducer (5) and at least two microphones (6, 7), a passive noise suppression system comprising a sound absorbent material (49). Said muffler module (4) comprises at least two electro-acoustic transducers (5) connected to the walls (40) of said bearing frame, in opposite positions, in such manner to leave the central part of said conduit (C) free. The sound beams coming from said at least two electro-acoustic transducers (5) are mutually combined, obtaining a resulting sound beam that can be directed towards a preferred direction by means of beam forming algorithms. |
