In existing soundtracks, the system recognizes nondirectional sounds like falling rain and sends them to the new speakers.

在现有音道中，系统辨识出像落雨声那样的无方向性声音并把它们传送给新的扬声器。

A radio beacon which transmits nondirectional signals whereby the pilot can use the ADF to determine his bearing to or from the station.

发射无方向信号的无线电信标台。据此飞行员能够用自动定向仪 （ADF ）确定他的背台或向台方位。