A voice recording has emerged in which Joan Rivers complains of trouble with her vocal chords.

The clip, which was taken on the same day she went into surgery to have the issue corrected, also sees the comedienne deliver some typically witty lines as part of a radio ad for her friend Brad Zimmerman's upcoming off-Broadway show, 'My Son the Waiter, a Jewish Tragedy'.

According to the New York Post's Page Six column, Rivers begins the clip by saying: ''I told [you] I didn't feel good. My voice has been bothering me. I don't know what it is . . . I feel like s***. I'm tired already.''

Later, she says: ''This is terrible copy. Who wrote this crap? I feel sick . . . Anyway, the critics are calling it hilarious, a total must-see, and I love him, too. So don't wait 29 years to see my friend.''

Rivers then complains: ''My voice is bothering me ... I can't ... I have to do it again.''

Finally, she adds: ''That's it - I don't feel good.''

Rivers died age 81 after suffering a cardiac arrest following a routine procedure on her throat.