Feedback - Home Remedies
a) Test for a fit problem by pressing the hearing aid tighter into your ear with your finger or the eraser end of a pencil (make sure you don't cover the microphone. If pressing it in or adjusting the angle stops the feedback, this indicates a fit problem. Although, if the feedback does not stop, that doesn't necessarily mean that it is not a fit problem.
b) Also try plugging the vent temporarily with putty or tape. If this helps, the fit may be a problem.
c) Try putting Keri lotion or Vaseline around the canal of the hearing aid before inserting it. If it is a small gap, this sometimes helps. d) Old time hearing aid dispensers used to put a coating of clear finger nail polish on the canal portion of hearing aids to make them fit slightly snugger. e) An ugly, but effective solution for very loose hearing aids is "[Poligrip-comfort seal strips](http://www.amazon.com/s/ref=nb_ss?url=search-alias%3Dhpc&field-keywords=Poligrip-comfort+seal+strips&x=0&y=0)". If it doesn't work, they can be removed.
f) Try Comply Soft Wraps. The Comply Soft Wrap is a strip of foam with an adhesive backing to stick onto hearing aids or ear molds. It reduces feedback and improves retention for hearing aids that are too loose.
g) Sometimes the best solution is getting a new ear mold or shell made. Check availability and prices locally for this, or find a hearing aid repair lab online. If you do go the online route, you might save money by getting an impression kit online also, rather than going local. HOWEVER, it is always the safest option to have your local professional take the impression and there are risks involved with taking your own. Plus, you will probably get a higher quality impression from an audiologist.
This is an excerpt from the longer article Whistling Hearing Aids - How to Stop the Embarrassment