My son has a severe hearing loss that was found when he was a newborn. We happened to luck out and he was born when our hospital was doing a trial of the Newborn Infant Hearing Program. He has the loss in both ears. The specialists feel the loss is caused in the middle ears. He has had a few ear infections and has tubes in his ears now. He has had hearing aids for about 8 months. He is starting to talk a little and understand a few questions we ask. I know ear infections can cause hearing loss, but Coty had the loss before he had any ear infections. My question is What can cause hearing loss?

Dear Mrs. Tucker,
Your little Coty is certainly receiving good audiologic follow-up. He was tested at birth and a severe loss was diagnosed. Testing later indicated middle ear pathology. Tubes have been inserted. Now you are being told that Coty's hearing loss is caused by middle ear infections. Naturally you want to know what type of hearing loss your son has.
There are three types of hearing loss: conductive, sensory and neural
Let's begin with a conductive loss. This type of loss results from pathology beginning at the ear canal and continuing through the middle ear. Wax build-up can cause a conductive hearing loss. A broken ear drum can also cause this type of loss. The eardrum is the entrance to the middle ear, which is an air filled space. When a person cannot 'pop' their ears, possibly the result of a cold or allergies, the middle ear can fill with fluid. And, middle ear fluid can also cause a conductive hearing loss. Conductive hearing losses are generally not greater than 60 dB in degree (moderately-severe), and they can be medically remediated. On occasion there is scarring on the eardrum or the small bones in the middle ear ear are harmed, and then hearing levels cannot be restored to normal. But in general, a doctor can treat middle ear pathology with no lasting hearing loss.
A sensory hearing loss occurs in the cochlea (the sense organ for sound). The cochlea is located beyond the middle ear, and it transmits sound to the hearing nerve. Diseases such as meningitis can cause a sensory hearing loss. There are also genetic causes such a syndromes or just gene mutations. A cochlear hearing loss is determined by Acoustic Brainstem Testing (ABR) and Otoacoustic Emissions Testing (OAE).
Neural hearing loss results when the nerve does not transmit sound clearly to the brain. This type of loss is also diagnosed by the use of ABR and OAE.
If Coty was diagnosed at birth, his test was probably ABR or OAE. Ideally, he should have been tested by both to determine the exact location of the loss. Now we come to the big question. Did your son have middle ear fluid at the time of the test? IF so, and if that is the only cause if his hearing loss, he should have normal hearing now with his tubes. If he had a sensory hearing loss and also middle ear fluid, his loss was "mixed" (conductive and sensory). The tubes will restore hearing levels that drop as a result of the fluid, but they will not change the sensory loss.
So your next step is to have Coty tested now that he has tubes. There probably is no longer a conductive aspect to his hearing loss and your physician and audiologist should be able to determine the exact degree and cause of his loss. And please share those test results with me. I am very interested to know what the audiologist found.
Also, please write again if you have more questions or if any of this is not clear. Audiology can be technical and often needs a bit more discussion. Thank you for writing!
Sincerely,
Kathleen Sutherland