August 5, 2013
Often patients, especially new patients, will remark on the extensive testing we perform and the equipment we use. Often they have never seen or experienced such an array of diagnostics examining various parts of the ear and hearing system. “For my commercial driver’s license test they just stood behind me and whispered”. “When they tested me at ____ (retail hearing aid center), we were in a room with other people and copying machines running. All I had to do was click the clicker when I heard a sound, but you’re doing so much more”, etc. Many patients seem impressed at our comprehensive test battery, but we like to explain the value of each test. They do not exist merely to give the appearance of thoroughness; we are gathering information and making judgments about a very elusive system that can’t be directly observed. This is the problem with ears.
Most of us learned in school that the ear has “three parts, the outer, middle, and inner ear” without a good understanding of where one region ends and another begins. Many people will complain of pain in the “inner ear” any time the sensation is deep and away from the pinna (the visible portion of the outer ear). In our office we use a high-resolution fiber optic camera to visualize the ear canal, and the patient can look as well. Barring wax or other occlusion or malformation, the tympanic membrane (eardrum) is as far as we can see even with a camera or microscope. Often the middle ear bones, or ossicles, can be seen behind some eardrums. The region that can be seen through the canal is just the beginning of the hearing mechanism.
The true “inner ear”, also known as the cochlea, lies past the ossicles and is encased in part of the temporal bone of the skull. Neither the oval window nor the round window provides even a reasonable view of the workings of the inner ear (perhaps they were poorly named!). The organs of hearing, where mechanical energy is converted to electrochemical nerve impulses that travel towards the brain, are housed in complex structures within the cochlea. Even advanced MRI, CT, PET or ultrasound imaging can inform the clinician if the inner ear is functioning normally, as the structures are neither bone, nerve or vascular in nature.
We have described the tests we use to locate damage in the outer, middle and inner ears in previous blog entries. We use them because visual inspection of the ear canal and the patients’ symptoms are simply not sufficient for a diagnosis. Often the eye can be fooled. Again we see the problem with ears! Patients with apparent eardrum perforations, as viewed through an otoscope or microscope, often prove to have a perfectly sound drum, as verified by tympanometry, an objective measurement that relies on reflected sound and measurement of ear canal volume.
Always opt for a full diagnostic evaluation when your ears are in question. Let us put you on a clear path to good hearing and ear health.