The plugs in my ears have no vents. I am using a smaller plug in the right ear and a larger one in the left ear. with a little fiddling I can stop the feedback.
How can my hearing affect the feedback when there is no volume control on these HAs. There is a button that apparently selects between two programs. One beep is low freq and two beeps is high freq. best as I can tell. The on/off switch is opening and closing the battery compartment.