Classifying Hearing Loss

As with any scientific discipline, at a basic level audiology is founded on categorization. Observing phenomena, then organizing that reality so as to make the complex more understandable, is the core of the scientific method.

The fact that October is National Audiology Awareness Month is a good time to review how hearing conditions are broken down into four comprehensive categories —conductive, sensorineural, auditory processing, and mixed.

When seeing a new patient, one of the first things an audiologist will do is attempt to pinpoint the exact type of hearing loss the person is suffering from:

  • Conductive Hearing Loss — In many ways the simplest type, this is a situation in which something is blocking or intruding into the physical structure of the ear canal and/or its components. It could be earwax, swollen tissue, fluid from an infection, a tumor or fibrous dysplasia (abnormal bone growth), or a tear of the eardrum.
  • Sensorineural Hearing Loss — This is when the normal communication channel between the ear and the brain is damaged, degraded, or flawed. This occurs in the inner ear when either cochlea or vestibulocochlear nerve fail for any reason.
  • Auditory Processing Disorder — Hearing loss that is not because of anything happening — or not happening — in the ear. It’s when the brain fails to process the information it is receiving — or at least process it within the range of what is considered “normal.” People with such issues usually hear sounds, just not the same ones that the vast majority of people do. It is a condition with striking similarities to dyslexia.
  • Mixed Hearing Loss — As the name implies, when some combination of the above come into play simultaneously. Figuring out what’s happening is even harder when more than one thing is happening.

When working with a hearing health professional, this is the framework he/she will have in the back of their mind while trying to help you.