Did you mean "sign off?" "A sign-off" can mean the words used at the end of a radio or television program, or the end of the broadcast day. "To sign off" can mean to say the closing words of a program. "Newscasters Chet Huntley and David Brinkley signed off with the words 'Good night, Chet.' 'Good night, David. And good night for NBC News.'" "And this is [so-and-so] signing off. Stay tuned now for [next program]." "And this is WMBR signing off. WMBR is owned by the WMBR Foundation and operated as a student activity by students at the Massachusetts Institute of Technology." (Closing music, then silence).

"Sing off" is when 2 or more people compete against each other to get through the next round in a singing show like "American Idol" or "The Voice". I hope it helps you:)