| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the muffling effect by arranging plural speakers in an active muffler. SOLUTION: In this active muffler having a first noise detecting means, a means mounted at a downstream side of a duct and outputting a muffling signal, an operating means calculating a muffling signal of a phase opposite to that of a noise signal detected by the first noise detecting means, and a second noise detecting means mounted at a downstream side with respect to the output means on the duct mounted at a noise side, a muffling signal output means is mounted on a branch pipe branched from the duct, and plural muffling signal outputting means are arranged in parallel.</p> |
