echo source

例句：

1. 1. Theecho from the lake is so clear thatit can be heard from a distance.
   湖面的回声如此清晰，以至于可以远听。
2. 2.The sounding source of the earthquake wasdetected by seismometers.
   地震的震源通过地震仪被检测到。
3. 3. Thereverberation source in the room createsa soothing ambiance.
   房间内的回响源创造了一种令人放松的氛围。