| 摘要 |
PURPOSE:To enable hearing and detection in a low-pass or a high-pass frequency range by compressing a frequency band signal containing a hard-to-hear area in the frequency to be converted into a audible frequency range. CONSTITUTION:An input signal containing a hard-to-hear frequency band is inputted into a frequency-voltage converter 1. Each frequency is converted into a voltage coresponding thereto with the converter 1. The voltage is inputted into a damper 2 to be damped by a fixed value. The voltage damped is inputted into a vltage control oscillator 3 and a frequency signal corresponding each voltage outputted. |
