I did a test with hot glue. Adding to different spots and finally had it completely covered over. It didnt help. I can change the sound by touching down on components.
I did not try adding a small load like you said Bob. Will try that tonight for a test. What i dont like about that solution is it will slowly drain the battery power if a person was to leave their main switch on for a day or two.
Was getting help from an engineer at Linear. He said i need to "use caps other than ceramic, such as aluminum electrolytic which are a bit bigger, but not piezoelectric in nature."
Im still not sure if Ferrite rings are a good option. Tried to change the title in the other thread. Please feel free to combine them if you like. I had an idea of maybe putting the voltage regulator on a small heat sink, then completely cover it with a type of sound reducing foam. Either from a bottle or buy a sheet and wrap it around the regulator and tape it together.
