| 摘要 |
PURPOSE:To enable the reverberation time in a hall room, to be almost continuously changed by forming a ceiling with an acoustic control member, and by setting the area of the ceiling variably. CONSTITUTION:The operating keys 19 of an operating board 20 are selected to be operated, and the then the kind of play is specified. After that, by a controller 17, out of a storage section 18, data on the paying-out quantity of the acoustic control member 12 of an acoustic reflection member or a sound absorbing member according to the play are read. After that, by the controller 17, according to the data, the motor 15 for a take-up device or a movable body is driven, and the movable body 14 is moved along rails 11, and the acoustic control member 12 is payed out or taken up, and the area of a ceiling 10 is set to come to a specified value. |
