It is normally a repeated tone, designed to assure the calling party that the called party's line is ringing.

这种声音一般都是一个重复的音调，目的只是提示打电话的人，对方的电话正在接通中。

youdao

It is normally a repeated tone, designed to assure the calling party that the called party's line is ringing.

这种声音一般都是一个重复的音调，目的只是提示打电话的人，对方的电话正在接通中。

youdao