A ringback tone (or ringing tone) is an audible indication that is heard on the telephone line by the caller while the phone they are calling is being rung. It is normally a repeated tone, designed to assure the calling party that the called party's line is ringing, although the ring-back tone may be out of sync with the ringing signal.
The ringback tone (or "RBT") is in most cases generated in the distant switch and transmitted in-band. A message is also sent over the signaling system (usually SS7). In most public phone networks the tone is not generated in the handset or by the local switch, as customized tones or voice announcements may be generated by the distant switch in place of a ringing signal.
Read more about Ringback Tone: Ringback Music, Ringback Advertising, Interactive Reverse Ringback Tone, Ringback Patents, See Also, References
Famous quotes containing the word tone:
“...I ... believe that words can help us move or keep us paralyzed, and that our choices of language and verbal tone have something—a great deal—to do with how we live our lives and whom we end up speaking with and hearing; and that we can deflect words, by trivialization, of course, but also by ritualized respect, or we can let them enter our souls and mix with the juices of our minds.”
—Adrienne Rich (b. 1929)