Hearing well depends on all parts of our auditory system working normally so that sound can pass through the different parts of the ear to the brain to be processed without any distortion. Hearing loss of any type can affect one or both ears and can range in severity from modest to profound. The type of hearing problem you have depends on which part of your auditory system is not responding well. Commonly, hearing loss is divided into three primary types based on the region where it occurs:
- Sensorineural hearing loss (SNHL) If the problem is somewhere between the cochlea in the inner ear and the brain, this is called a sensorineural hearing loss. The pathway through the outer and middle ears is functioning normally but, after sound arrives at the cochlea, it isn’t processed normally either because of damage to the delicate ‘hair cells’ in the cochlea or to the auditory nerve or because of defects in the auditory pathway leading to the brain.
There are many causes of sensorineural hearing loss but exposure to excessive noise or the effects of ageing are the most common. SNHL impairs the capacity to detect faint sounds. Even when speech is sufficiently enough to be audible, it may still be unclear or muffled.
- Conductive hearing loss If you have a problem in the outer or middle ear, it means that there is inefficient transfer of sound to the cochlea in the inner ear. Generally, this affects the volume of sound so that it simply doesn’t seem loud enough.
A typical example would be the effect of a blockage of wax in the ear canal or a perforated eardrum. This is called a conductive hearing loss because sound vibrations are not being conducted efficiently. The cochlea is still working normally but simply not receiving enough information via its connection with the middle ear. This form of hearing loss is often treatable with medication or surgery.
- Mixed hearing loss as its name suggests, is a combination of sensorineural and conductive hearing loss, and it can affect the inner, middle, and/or outer ear.
The type of hearing impairment you have will decide the most effective treatment for you.