This woman consulted a doctor, explaining that for many years she sufferred from excessive farting, but there was never any sound or smell so she had done nothing about it. So the Doctor took down all of her medical history, a process that took quite a while.
At the end, the woman says, You see, Doctor, while Ive been sitting here talking to you Ive broken wind five times, but theres no sound and no smell.

At this point, the Doctor scribbled something on a pad, ripped off a sheet and handed it to the woman. Whats this? she asked, some pills?

No, replied the Doctor, that is a prescription for a hearing aid; come in next week, and we will operate on your nose.