| 摘要 |
<p>A room microphone (RM) (6) links to a pre-amplifier (10), a current rectifier (11), a threshold detector (TD) (12) and a retriggerable monostable multivibrator (13). The RM picks up noises produced by a baby, converts them to electric signals, amplifies them and then rectifies them so as to forward them to the microphone. The TD determines whether the signals lie beyond a preset threshold.</p> |
