Hope I haven't posted this one already...
An old woman goes to her doctor with an odd complaint.
"Doctor, I have this embarrassing problem with gas, and I don't know what to do. My farts don't smell, and they're silent, but still, just knowing it's happening embarrasses me to no end. You probably haven't noticed, but I've already farted five times since I came into your office! Can you help me?"
The doctor frowns, grabs his pad, and scrawls a prescription down. "Take these for a week, and come back and see me."
A week later, the woman returns, visibly upset.
"Doctor, I don't know what you expected those pills to do, but they've made things worse! My farts are still silent, but now they stink to high heaven! I'm afraid to go out in public!!"
"Well, ma'am, now that we've cleared up your sinus problem, let's work on your hearing..."