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Can You Hear Without Ears?Can you smell without a nose?

By Christopher Beam
Posted Wednesday, March 21, 2007, at 6:47 PM ET

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On Saturday, Taliban guerrillas punished a group of Afghan truck drivers suspected of collaborating with U.S-led troops by chopping off their ears and noses. Can the victims still hear and smell?

Yes, but with more difficulty. The outer part of your ear, known as the pinna, funnels sound into your ear canal, like a megaphone in reverse. If someone cut it off, everything would sound quieter. (A wound that scabbed over would make the sound suppression more severe.) The pinnae also tell you where sounds are coming from: The ridges and grooves shape sound waves differently depending on where the sound originates. As a result, the brain learns to associate certain amplification patterns with certain directions. So, if you lost your ears, you might be able to tell what music you're hearing, but not where the speakers are.

Likewise, the nose funnels air (and smells) toward receptor neurons,* which sit behind the face and near the front of the brain. You can't really damage this odor-sensing area by slicing off cartilage. More likely, cutting off someone's nose will affect their breathing, which in turn affects their ability to smell. The front of the nose has two main functions: It guides airflow and filters out dust and other large particles. The nostrils direct incoming breaths up and over turbinates located behind the nose. These turbinates secrete moisture to humidify the air before it reaches the receptors. At the same time, particles get stuck in nasal mucus before dripping or getting sneezed out. Without a nose, you'd end up inhaling more dry, dusty air—which makes Saturday's nasal severance especially cruel, given Afghanistan's arid climate.

Of course, if you lose your ears and nose, you can always get new ones. Doctors sometimes make ears for children born without them—a deformity called microtia. The process is complicated, though: Surgeons take a graft of cartilage from the ribs, carve it into the shape of a pinna, and implant it under the skin. (They often graft skin onto the back of the fake ear to make it protrude.) The entire process—three or four surgeries in all—can take up to two years. Adults with severe skin cancer on their ears usually get a prosthetic ear instead of one generated from their own tissue. (Plastic ears can be amazingly realistic.)

Reconstructing a nose is easier. Doctors cut a flap of skin loose from the forehead (leaving it attached between the eyebrows to preserve blood flow) and rotate it down to cover the nose area. To recreate its structure, they can take bone from the patient's skull and cartilage from the ears, and then lay the flap of skin over it. If you're only replacing a small piece of the nose, you can sometimes reconstruct it using a pie-shaped piece of cartilage from the ear. (For patients without ears, doctors can use rib cartilage instead.)

Got a question about today's news? Ask the Explainer.

Explainer thanks Dr. John Oghalai of the Baylor College of Medicine and Dr. Madan Kandula of Advanced Ear, Nose & Throat Specialists.

Correction, March 23, 2007: This article mistakenly stated that the olfactory receptors are located on the olfactory bulbs, instead of near them. (Return to the corrected sentence.)

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Christopher Beam is a Slate political reporter.
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