Trying To Place A Call for 12 Hours ( Ringback tone, ringing tone )
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.
http://en.wikipedia.org/wiki/Ringback...
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