I’m 110% with Nevada on this. What you need is a different mechanic.
If my count is right, he has RETURNED the car to you FOUR TIMES with the noise still present. Or is it five? Why on earth would he return a car that still had the problem you asked him to fix?!? That’s crazy. If he can’t even recognize that the noise is still there, then you definitely don’t want him touching your car ever again!
If you don’t know any other mechanics in your town, look at the “mechanics files” at the top of this page. And ask everyone you know for recommendation for other shops to consider. But do not go back to this guy, except to insist on a refund for the work he did and charged you for which did not fix the problem.