QC20 Right Ear Feedback Noice when Noise Cancelling Activated
The right ear on my QC20's has recently developed a loud squealing like noise, similar to feedback, when the Active Noise Cancelling (ANC) is activated and the earbud is in my ear. Removing the earbud, the noise goes away, placing my finger over the earbud and the noise returns. I've removed the rubber cover and checked for debris in the earbud speaker canal and it all looks clear. The filter is in place. If I place my finger over the speaker canal with the ANC on then the squealing / feedback noise starts. Its almost like there is a blockage somewhere causing feedback to occur into the ANC. This has made the earbuds unusable with the ANC active. Any tips?
The headphones themselves are around 5 years old and have been absolute rock stars having been used almost daily and having been worn for many hours of transpacific flights. To say that these headphones have served me well would be an understatement.
Tips to keep them going would be appreciated.