Do the big ears of, say, Gary Lineker or Prince Charles help them to hear better than small ears?

Our ears aren't direction-finding, like those of bats or deer. And they play little part in collecting sound waves, so people with small ears collect sound and channel it towards the outer eardrum just as well as those with spaniels' lugs. Seals have no external ears, and sea lions have quite prominent ones, yet there's no suggestion that their abilities to hear are different. It's when the sound passes through the eardrum and is magnified by the three bones in the middle ear that the process of hearing efficiently really starts. The ears attached to the sides of our heads play no part in this process. So their most important use is merely to hold our glasses.

Why do my calves ache the day after I've been drinking?

That's not a good sign. You must be drinking so much that you are putting your 'electrolyte balance' out of kilter. To function properly, your muscles need exact levels of sodium, potassium, calcium, and bicarbonate, along with other electrolytes, plus the right levels of glucose in the blood. Disturb them and you are asking for cramps and spasms. Add to that rising levels of lactate in the muscles, because you have used up all your glycogen reserves, and you have a double whammy. Heed the warning and drink less. If your muscles are complaining like this, think of the organs you can't feel, such as your liver and brain.

· Do you have a question for Dr Smith? Email doctordoctor@theguardian.com