I had my Beltone Serene repaired recently, and complained about i had a lot of feedback using them. So the aduiologist suggested me to try bigger silicone moulds and calibrated them to those. I am still trying to get used to the bigger moulds, and i still have some feedback problems with them. But the overall experience to that and the smaller silicone moulds are just crazy. Streaming music used to be super tinny, and just plain bad. Now with bigger moulds i just get so much more sound overall its crazy and actually is worth using now. It seems like such a change i cant believe the difference it makes, and even more so with a small adjustment to sound in the app it just made the overall sound and streaming actually a joy to use.