People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss . In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter,  stimulator and receiver, and electrode array.

Watching a speaker's lips is like hearing speech by eye instead of by ear and markedly improves speech perception. In this review I summarise studies over the last sixty years about lip reading, it's issues, methodological problems, experimental and co relational studies, issues of cerebral lateralization, localization and cognitive and neuro psychologic function. Several studies on speech reading in general suggest that hearing impaired groups actually do not possess superior speech reading skills compared to normal controls. With function magnetic resonance imaging (FMRI) it was also found that the linguistic visual cues are sufficient to activate auditory cortex in the absence of auditory speech sounds. Here I presented data and arguments about all aspects of the phenomenon of lip reading and it's use in rehabilitation audio logy

Background and Aim: Neuroimaging techniques in audiovisual speech processing are innovative approach to neuroscience investigation that steadily influences the deep survey of highly mechanisms involved in this process. The purpose of this study was to evaluate brain activity via functional magnetic resonance imaging throughout audiovisual speech perception in Persian language.
Methods: Functional MRI was used to assess 19 normal 20-30 year old women while they had been presented syllable /ka/ visually and /pa/ auditory using block design method, in which it would provide two series of imaging, functional and T1-weighted. Subsequently, the results were analyzed and compared by FSL software.
Results: The results of this study pointed out that both middle and cortical regions of brain are activated in visual stimuli and its middle regions are activated in response to auditory stimuli. Hence, left anterior supramarginal, some parts of motor speech system including insular and cingulate cortex-precentral cortex were stimulated with visual stimulus and left posterior supramarginal as well as right supramarginal gyrus were stimulated with auditory stimulus. Moreover, in this investigation, McGurk effect was behaviorally proven in fifteen subjects.
Conclusion: It was hypothesized that the activation of unique region, supramarginal gyrus, with both audio and visual stimuli indicated the presence of commonplace region for phonologic processing of sensory inputs. In addition, auditory stimuli develop more intense activity and on the other hand, broaden-maximum voxel-as well as extra regions are demonstrated in response to visual stimuli. These points represent the unfamiliarity of normal individual brain to percept visual speech stimuli.