An old lady went to the doctors; I dont know whats wrong with me, she says. I keep farting but my farts are silent and odourless. In fact, Ive farted 20 times since walking in here without you noticing.

The doctor gives the lady some medication and instructs her to return in a weeks time.

At her next appointment, the lady has noticed a change.

I dont know what was in those pills you gave me, but my farts now stink like hell. Theyre still silent, though.

The doctor smiles. Well, now that weve cleared up your sinuses we can work on your hearing.