| 摘要 |
PURPOSE:To make it possible for a person to feel noise as comfortable sound by sending the noise from a speaker arranged in a room through an electric filter whose pass band can be controlled, analyzing a receiving signal of a microphone by an acoustic spectrum monitor and controlling amplifiers constituting the electric filter in accordance with the analyzed result. CONSTITUTION:When the gain of respective amplifiers A1 to An constituting the electric filter 2 is fixed, the output power spectra of respective narrow band pass filters(BPFs) F1 to Fn are fixed. Since the power spectra are distorted by acoustic characteristics in the room, the output power spectra of the narrow BPFs F1 to Fn constituting the acoustic spectrum monitor 5 are not fixed. A control part 6 detects the unfixed output power spectra of the narrow BPFs F1 to Fn and increases the gain of the amplifiers A1 to An in the filter 2 corresponding to the narrow BPFs F1 to Fn. Since the room can be filled with noise with optional spectra, the person can feel the noise as comfortable sound. |
