一种定义
四种语言
0,1,2
- 德國
- 英語
- 中國
- 西班牙語
声音 (v)
loten (z.B. Echolotung) (v)
sound (v)
The effectiveness of the sound insulation depends on the excitation frequency.
The following formula shows how wave length , frequency and sound velocity are related: .
Measurements can also be taken at the source of the sound.
