Why miss a decibel of life?
Sensorineural hearing loss
This is the most common type of hearing loss. It has its origin in the inner ear or along the auditory nerve. Most commonly, the damage occurs in the inner ear (cochlea). In this instance, the hair cells in the cochlea are damaged and cannot transmit neuro-electrical impulses to the brain. Sensorineural hearing loss can be congenital (present at birth) or acquired after birth.
Common congenital causes include:
- Hereditary factors
- Viral infections
- Prematurity
- Birth trauma such as anoxia
Acquired causes include:
- Reactions to ototoxic drugs (damaging to the hearing system)
- Head injury
- Noise exposure
- Aging
- Ear infections
- Meningitis
- Encephalitis
- Ohter diseases
The audiogram displays a sloping hearing loss from 20 dB HL in the low frequencies up to 75 dB HL in the higher frequencies and (nearly) equal in both ears. Such a hearing loss can usually be amplified sufficiently by using conventional hearing instruments.
Learn how to read an audiogram
If sensory hearing loss in speech relevant frequencies exceeds values of about 80 to 90 dB HL, it might become difficult to make speech adequately audible. The reason here is that even though the person suffers from profound hearing loss, he/she nevertheless regards extremely loud sounds just as uncomfortable as a normal hearing person would. The challenge here is to fit the complete speech spectrum into the individual's residual dynamic hearing range. If this range is reduced to 10 - 20 dB, conventional hearing instruments cannot provide sufficient amplification anymore.
In these cases a cochlear implant (CI) might be the solution. A cochlear implant processes sounds and transforms them directly into electric impulses. The cochlear implant replaces the functionality of the inner ear. The electric impulses directly stimulate the auditory nerve. The auditory process in the brain is thus triggered. However, for the brain to interpret sounds correctly, patients need to have either adequate former listening experiences, or should be treated with a CI within the first four years of life.
Even under ideal conditions, patients provided with a cochlear implant need a lot of auditory training and continuous support. Even then, there is no guarantee that a CI works to every patientÂ’s satisfaction.
