An old lady goes to the doctor and says, "I have this problem with frequent gas. Fortunately, the farts never smell and are always silent. As a matter of fact, I've farted at least 10 times since I've been here, and I bet you didn't even notice!"
The doctor says, "I see. Take these pills and come back next week."
The next week the old lady returns. "Doctor," she says, "I don't know what the hell you gave me, but now my silent farts stink like the dickens."
The doctor says, "Good! Now that we've cleared up your sinuses, let's work on your hearing."