AceShowbiz - Cher spent months avoiding her transgender son Chaz Bono as he went through the process to become a man - because she was terrified she wouldn't recognize him as her child. Bono was born Chastity - Cher and ex-husband Sonny Bono's only daughter - and she broke her mother's heart when she came out as a lesbian.

Chaz feared more heartbreak was to come when he revealed his plans to undergo a lengthy and extensive sex change procedure, but Cher took the news well. However, once the process started, the pop superstar kept her distance.

In new documentary "Becoming Chaz", which debuted on Oprah Winfrey's new OWN network on Monday, May 9, Cher says, "I was so nervous. I hadn't seen her... and I was putting it off. My boyfriend finally said, 'This is crazy, just do it.' I said, 'I'm so terrified of what will happen. If I don't recognize her, what will happen?"

Cher admits there are many changes she's slowly having to come to terms with: "At some point, I'm gonna have to start calling her 'him'... It doesn't seem comfortable to me yet. Actually I just can't remember... and I guess I'll start forcing myself... (but) I'm not sure she cares."

And she reveals she asked her transgender son if she could have a copy of his old voice mail message - because it was her daughter speaking. She adds, "I was hysterical one day because I was calling Chaz's answering machine and I realized it was her old voice, and then I said, 'Chaz is there a way I can save it because I will never hear that voice again?' And there wasn't, it was gone."

"That's the most traumatic thing that has happened to me in this whole thing - hearing her voice and knowing I'll never hear it again."