(one) can't believe (one's) ears
One is shocked by what one has heard. I can't believe my ears! You're not playing with me, right? I really got the job?
not believe (one's) ears
To be shocked or surprised by what one is hearing or has heard. I can't believe my ears! You're not playing with me, right? I really got the job? Jen didn't believe her ears when she heard her sister say that she was moving to Texas.
not believe one's ears
Fig. not believe the news that one has heard. I couldn't believe my ears when Mary said I won the first prize.