I guess it all depends on how much experience the NHS A.uD has @Zebras… Usually, if I have had problems with an aid, the NHS A.uD with listen for themselves, placing the aid in a stethoscope type instrument, and then they are able to hear the aid for themselves… I am astonished Ruth, a known issue wasn’t checked first, having said that, it is perhaps a fairly rare thing, but you would imagine, with the amount of patients that the NHS have, and the amount of BTE’s they issue, they would have come across the blocked damper problem before? I am delighted you have solved the problem @JohnD2, I would be inclined to go to your appointment John, that way you can inform this A.uD, so some other poor hearing aid user, isn’t a hearing aid down for months on end! And while you are there, ask them for an upgrade to a better set of aids, you might embarrass them into giving you, the Phonak Naida Paradise 70 UP’s, which have Bluetooth… If you don’t ask, you don’t get! Good Luck, cheers Kev