Immediate fix!
One of my NHS hearing aids stopped working. I changed battery but that didn't sort it. I looked online for details of where to go to get it looked at but information on repairs was not evident. I decided to go to the Audiology dept. at West Suffolk Hospital either for a repair or for information on where to go. In the event the person on reception pulled various bits off and examined them, fitted a new tube and it was all systems go!!! Immediate fix.