Terms for subject Rail transport containing audio

English	Chinese
audio alarming	发声报警
audio communication circuit	音频通信电路
audio communication circuit	音频通讯电路
audio-frequency track circuit	音频轨道电路
automatic block with audio frequency shift modulated track circuit	移频自动闭塞
Digital and Audio Announcements	数字语音广播器
pilot audio frequency signal	导音频信号