| 摘要 |
PURPOSE: A soundproofing using a band-pass filter is provided to protect noises by using a method of using a frequency filter instead of a method of absorbing noises. CONSTITUTION: In a soundproofing, a text display device(100) displays a frequency. An inductance adjusting device(300) controls inductance. A capacitor adjusting device(400) controls the capacitor. A specific frequency is passed in a first step and is displayed as a text in a second step. |
