To multilayer acoustical panel, the complex transmission coefficients of multilayer both forward and backward incidences are definitely the same.
对多层均匀介质板，正、反两方向上的正入射复透射系数相同。
2
In the oil - well monitoring system, the data transmission method using acoustical waves as carrier waves via the wall of oil pipeline can bring cost savings and reliability.
在油井监测系统中，以油管管壁作为信道的声波通信方法可以降低成本和提高可靠性。
3
The acoustical and communications engineer is concerned with the generation, transmission and absorption of sound.