Ochlear implantation and electro-acoustic stimulation: Current status and developments

The number of people with hearing loss constitutes approximately 6.5% of the world population. Hearing loss leads to alienation from social environments and deterioration in quality of life in adults. Children with hearing loss, on the other hand, have lower literacy and lower educational attainments. There are auditory prostheses, called cochlear implant (CI) devices, which are designed using a special speech coding strategy to convert acoustic information into electrical stimulation for patients with inadequate traditional hearing aids used for rehabilitation of hearing loss. These devices are surgically implanted and cause direct stimulation of primary afferent neurons in the inner ear. The auditory nerve is stimulated by the electrodes placed on the cochlea, and thus the auditory message can be sent up to the auditory cortex. With CI, increases in speaking, language and comprehension skills can be achieved.