| 摘要 |
When, in conventional sound systems, signals of sounds collected by a microphone are amplified and the amplified signals are applied to an ear by an earphone and a headphone, too loud sounds and environmental noises are unpleasant, and the intelligibility of words are poor. Hence, such problems are to be addressed. In addition, downsizing and performance improvement for sound apparatuses are to be accomplished. A signal having undergone an amplitude limitation with reference to an output potential of a high cut filter 17 which is an output by a low cut filter 12 in a high frequency band and inverted by an inverter 14 is added with, by an adder 15, an output signal from the high cut filter 17, and an addition signal is output. |
