speech transmission

例句：

1. 1. The new phone has a built-in microphone for speech transmission.
   这款新手机内置了麦克风，用于语音传输。
2. 2. Inthe old days, people used to transmittheir messages through the airwaves.
   在旧时代，人们曾经通过无线电波来传递信息。
3. 3. The scientists are trying toimprove the efficiency of speech transmission in communicationsystems.
   科学家们正在努力提高通信系统中语音传输的效率。