Question

please help me solve this riddle. "you've heard me before, yet you hear me again. Then I die, Til' you call me again." Who wrote this riddle?
Ms. Sue
http://wiki.answers.com/Q/You_heard_me_before_Yet_you_hear_me_again_Then_I_die_Til_you_call_me_again_What_am_I
Anonymous
Echo