| 摘要 |
PURPOSE:To reduce deterioration in sound quality by storing sequentially a state of a volume control circuit and a state of howling control means so as to discriminate a level difference of howling. CONSTITUTION:The equipment is provided with a volume control circuit 7 to generate howling, a howling detection circuit 8 detecting the occurrence of howling and its frequency, a level difference discrimination circuit 10 discriminating a level difference used to detect the occurrence of howling before and after the filter setting from the volume control circuit 7, and a display means 11 displaying a discriminated level difference as a gain improvement effect by the filter setting. Thus, the gain improvement effect by the filter setting is recognized based on a difference between a volume level when howling suppressed by the filter and a volume level when howling is detected after filter setting, and the gain improvement effect is informed to the operator by displaying the result. |
