Many people have more than one disability.
The prevalence of most forms of impairment increases considerably with age, and therefore the population of people with disabilities grows disproportionately as life expectancy rises. This does not influence speech communication itself but makes it hard to make a phone call or use a wide range of other telecommunication equipment. Impaired Reduced function of legs and feet means depending on a wheelchair or artificial aid to walking. In addition to people who are born with a disability, this group includes a very large number whose condition is caused by age or accidents. Wheelchair user 3 Million Cannot walk without aid 45 Million Speech, Language and Cognitively Impaired Speech impairment may influence speech in a general way, or only certain aspects of it, such as fluency or voice volume.