摘要 |
PURPOSE:To prevent production of noise sound at changeover by decreasing an intensity level momentarily and increasing gradually under a required time constant when the audio intensity level is switched from a low to a high level through the provision of a buffer means. CONSTITUTION:An audio signal outputted from a speaker 4 is switched to a low level or a high level by a changeover means 2 in response to a switching signal from a switching signal generating circuit means 1. When the low level is switched into the high level, the audio signal switched to the strong level is reduced momentarily by a buffer means 3 and the level is increased under a prescribed time constant. Thus, even when the intensity level is switched from the low level to the high level, production of sound noise is prevented. |