| 摘要 |
PROBLEM TO BE SOLVED: To easily recognize an audio state even at time of silence by storing the volume value of an amplifier as a target value, when power is turned off previous time, reading the target value when power is turned on at this time, increasing the volume value from a prescribed value around zero and energizing an audio signal generation circuit and a feedback sound generation circuit. SOLUTION: A control part 1 reads a volume value from a memory 2, when power is turned off at previous time with the turning on of power, sets a target value and controls the volume value against a preamplifier part 6 to zero or to the prescribed value, which is substantially zero and compares the present volume value with the target value. Since the present value is smaller than the target value at first, a feedback sound generating circuit 5 is energized, a feedback sound is rung once and the volume value is increased by one stage. The operation is repeated and the volume value is fixed in the case that the present value is equal to or larger than the target value. An audio signal is reproduced, and the feedback sound generation circuit 5 is de-energized.
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