The cochlear consists of many cells called hair cells, which are responsible for detecting sound waves, and sending electrical signals to the brain. When these hair cells are damaged – either due to old age or prolonged exposure to loud noises, they become less effective at sending electrical signals to the brain. As a result, the person’s hearing ability worsens and would be diagnosed with sensorineural hearing loss. Cochlear implants can only be effective for a patient with sensorineural or mixed hearing loss, whereas hearing aids can cater to patients with sensorineural or conductive hearing loss (i.e. sound has difficulty reaching the inside of the ear through the ear canal), or both.