| 摘要 |
PROBLEM TO BE SOLVED: To change over the sound volume level and display of each loud speaker without applying muting, etc. SOLUTION: Sound volume levels of four loudspeakers located on the right and left in front and rear in a cabin respectively are divided into a plurality of steps and stored in a storage part 4, and when an operation part sets an input of a change is a sound level, a signal processing part 8 compares the sound volume level at a present step with that at the step of the input setting, and operates calculations to make the present sound volume level approach to the set sound volume level with each loudspeaker kept singing, therefore, it is possible to control sound volumes of each loudspeaker without muting, etc. Moreover, since a display control circuit 2 controls a display part 1 according to each sound volume level, it is possible to visually display a sound volume level according to change in the sound volume level. |
