The benefits of cochlear implantation are diverse and cannot be described by a single measure. Almost all patients receive some benefit, although there is a range of performance.
The cochlear implant allows a hearing impaired individual to access speech information and environmental sounds; this usually improves the quality of the voice and speech production in deafened adults and gives young children the potential to develop spoken language. In terms of hearing speech, some patients find the signal from the cochlear implant helps with their lip-reading skills, while others find they no longer rely on lip-reading at all and can even use the telephone.
Benefit can be measured using tests of auditory and linguistic performance; however patients or parents often report more general improvements, for example confidence, behaviour and quality of life. These may not be reflected in the scores on audiological tests.