Cochlear implants are electronic devices that help people with severe hearing loss gain hearing by stimulating the damaged auditory nerve directly through electrodes. Cochlear implant technology began in the 1950s and has been around for more than 40 years. More than 50,000 people in 61 countries worldwide have undergone the procedure. The mechanism of speech production Speech production is accomplished by instructions to peripheral generative organs under the control of the central nervous system. The instructions are first confirmed by the cerebral cortex, which transmits them to the motor cortex in the pre-central gyrus of the frontal lobe of the brain, which then transmits them to the motor nuclei in the brainstem and to the spinal cord, and then to the muscles of the respiratory, laryngeal and articulatory systems. Classification of speech sounds Vowels are defined as speech sounds in which the vocal tract is unrestricted. It is expressed as a quasi-periodic process of modulating the exhaled airflow through vocal fold vibration. Consonants are speech sounds with a constraint or obstruction somewhere in the vocal tract. Turbulence is generated when the exhaled airflow passes through this constraint, acoustically resulting in an irregular sound wave. The corked sound is pronounced with the uvula elevated, the nasopharyngeal passage closed, and the sum closed somewhere in the oral cavity. The release of the corked sound is the relief of the air pressure built up by the closure and harmony, which acoustically results in a burst sound. Phonological problems in the speech of deaf children The position of the tongue contraction affects the articulation errors, the tongue is too far back causing an occlusive nasal sound, such patients can be trained to bring the tongue forward and to pay attention to the seating position. Match the tip of the tongue to the gingiva and practice /t/ /d/ /s/ /z/. A tongue that is too far forward will make the sound thin and lack the resonance of the back vowels. You can practice /i/ /e/ /o/ /u/ and also pronounce the back vowels as loudly as possible. Hearing Speech Rehabilitation The process of rehabilitation is different for different patients. Patients with adult post-verbal deafness have established an auditory speech system before deafness and are able to understand speech and communicate. Combined with a period of training after switching on, they can grasp sound signals more quickly. Restore the principle of encouragement: give them the experience of success and build confidence. Ensure a quiet environment, start with familiar content, provide rich sounds, and evaluate regularly.