| 摘要 |
PURPOSE:To muffle even a sound generated from the speeds of revolution which are not synchronized with each other by calculating a control signal for eliminating a detection signal which is fetched separately by synchronizing with every rotating body of each noise source at every sound source, fetching a signal by synchronizing with each rotation signal, superposing these signals and outputting them to a muffling loudspeaker. CONSTITUTION:With respect to rotation signals from plural sound sources 1, 2 for giving a noise, control signals are calculated separately, respectively, based on outputs of rotary sensors 6, 7, and outputted as a superposed control signal by a controller 16. Accordingly, from a complicated residual sound signal, the control signal can be calculated very exactly and easily. Also, it is superposed and outputted. In such a way, even if there are two sets or more of noise sources 1, 2 which are movable independently each other and have the speeds of revolution which are not synchronized with each other, a residual sound can be converged very efficiently. |
