transmission noise

I had a rear main bearing replaced and they changed the clutch and throughout bearing while at it. Afterwards the car has a noise (grating crickets?) when accelerating or decelerating with the clutch engaged. The noise goes away when the clutch is depressed. The shop doing the work says it's not them and sent me to a transmission shop. The transmission shop said it was the throw-out bearing. I thought throw-out bearings generally made noise only when pressing the clutch.