External auditory Canal

May 15, 2008
Conduit auditif externe
The external auditory canal is not simply a tube that brings sound to the eardrum. It has a specific shape to permit the resonance of sounds and has a complex maintenance mechanism that shouldn’t be disturbed.

The auditory canal is not straight, but is angled in various ways depending on the individual. It is composed of two portions which keep it open. The first portion is made of cartilage; it’s actually the prolongation of the external ear cartilage, this keeps the ear from closing. The second portion is made of bone; it allows sound to be amplified and reach the eardrum.

Recent discoveries demonstrated great individual variations of the diameter of the auditory canal. In fact, it can range between 10 to 2 mm! These variations are generally hereditary and may lead to particular problems which must be addressed.

How does the ear protect itself?

The sebaceous glands and the little hairs in the external part of the auditory canal protect the ear by limiting the access of foreign bodies and dust particles. The production of wax in large quantities also has a role in the resonance of the auditory canal. The displacement of superficial cells inside the auditory canal towards the outside of the ear also drives wax, other secretions and foreign bodies with it.

Some individuals who produce abnormal wax may have various problems. For several people, the abnormal migration of superficial skin cells towards the outside of the ear can lead to the production of scales and dandruff. This can cause a blockage in the ear or result in a film lining the ear canal, disrupting the proper use of the hearing aids.

Greater is the accumulation of wax in the ear canal; greater are the risks of developing an external ear infection. It is a vicious cycle which can be an important obstacle for the use of hearing aids. Therefore, it is important to remove wax, but also to treat the consequences of its accumulation.

If your auditory canal is abnormal in any way, including of reduced size, you should consult your family or Ears-Nose-Throat (ENT) doctor every six months to ensure the external auditory canal’s proper function.