| 摘要 |
PURPOSE:To attain a vivid sound audibility despite reverberation in the room by storing in a memory means an impedance value corresponding to the acoustic absorptivity around the speaker, comparing the stored value with a measured one by a comparing means to judge the acoustic absorptivity, and by controlling the amounts of delay and attenuation of the additional sound by a controlling means. CONSTITUTION:Switches 12a and 6a are turned to A-side, and an impedance measuring signal 1 is supplied to the speaker 7a to measure then impedance by an impedance measuring circuit 8. The measurement result is compared with the impedance value corresponding to the acoustic absorptivity stored in the storing means 10 by a comparing-judging means 9. After the means 9 judges the absorptivity, the controlling means 11 outputs a control signal to execute the adjustment of the delay time of the delayer 3a and 3b and the attenuation amount of the attenuators 4a and 4b corresponding to the acoustic absorptivity. Then the switches 6a and 6b and those 12a and 12b are switched to B-side. A signal that underwent the delayers 3a and 3b and the attenuators 4a and 4b is added to a signal from an sound source 2 by adders 13a and 13b, and is reproduced by speakers 7a and 7b. |
