ringback tone

基本解释

What is a Ringback Tone?
彩铃英语，什么是彩铃?。
A ringback tone is an audible indication that is heard on the telephone line by the caller while the phone they called is still in use.
随着数字产品的普及，个性化的定制服务也在走向每一个普通人。打电话时，我们听到的不再是单调的“嘟嘟”声，而是悦耳动听的音乐。
Ringback music, also called personalized ringback tone, is a piece of music heard by the caller instead of the traditional telephone ring signal when a telephone call is placed.
“个性化接通回音”）则是打电话时，传统的电话提示音被音乐所取代，于是成为了我们所说的“ 彩铃”。
12530xiazai.com

Apparently white people haven't yet mastered the art of making a ringback tone that sells, because the Caller Tunes chart is dominated by hip hop acts, with Lil Jon (aka Mr. Crunktastic) grabbing the top two spots.
ENGADGET: Lil Jon dominates T-Mobile Caller Tunes (aka ringback tones) chart