Cochlear implants, also known as electronic cochlear implants, are currently effective in helping adults and children with severe and profound deafness to regain hearing and speech function. Some patients may ask what is effective after cochlear implantation? The post-cochlear implant evaluation includes both the ability to hear and the ability to speak. This means the ability to hear, the ability to hear and understand speech, and the ability to speak clearly on the basis of hearing. Nerve Response Telemetry (NRT) is performed after cochlear implantation to determine whether the impedance of the electrodes is normal or not, and to determine whether the electrodes in the cochlea are open or short-circuited. The application of NRT technology can directly measure the electrically evoked compound action potential (ECAP), which can reflect the functional state of the auditory nerve fibers after electrical stimulation, and can be used to detect whether the implantation has been successful during CI surgery. 2.Electrically evoked auditory brainstem response (EABR) The origin of each wave of EABR is basically the same as that of each wave of ABR. Successful EABR testing can accurately and objectively reflect the functional status of the auditory nerve and the auditory conduction pathway of the brainstem. 3. Cochlear hearing threshold test – whether you can hear after wearing a cochlear implant Cochlear hearing threshold is a test of hearing acuity after cochlear implant surgery. Hearing threshold only partially reflects auditory rehabilitation, as increased audibility in quiet conditions does not necessarily mean increased speech intelligibility in everyday conditions, especially in noisy and reverberant environments. The ultimate goal of cochlear implantation is to enable the patient to understand speech and restore or develop language function. Speech and language assessment can clarify the efficacy of the treatment and also help in the improvement of cochlear implant performance and the development of rehabilitation programs. It is generally recorded using either (1) the speech recognition rate (SRS), which is important in the diagnosis of the lesion site, evaluation of conversational ability and rehabilitation outcome, or (2) the speech recognition threshold (SRT), which is the minimum speech level required for a listener to understand 50% of the speech signal for a given speech examination material. 5. Questionnaires Auditory Efficacy-Auditory Behavior Rating Questionnaire: Speech Efficacy-Speech Intelligibility Rating (SIR) and Meaningful Auditory Integration Scale Test (MAIS) questionnaires; Meaningful Auditory Integration Scale Test for Infants and Toddlers (for infants and toddlers under 2 years of age). Additional assessments of telephone use, acoustic analysis of voice and speech rhythm, and music perception were also used for evaluation. PET is a functional imaging technique based on radionuclide imaging, in which substances required for human metabolism (e.g., glucose) are labeled with radionuclides to create an imaging agent that is injected into the body and distributed throughout the body with blood flow. The results of the PET examination after CI show that the CI leads to functional reorganization of the cochlear implant in the auditory cortex.