These unique language systems are often called "home sign." The name reflects the fact that it is often only used at home, is often poorly developed, and fully understood among only a few individuals.

At different points throughout history, and even today, some parents believe that allowing their deaf child access to sign languages-even ones as basic as home sign-will cause them to become less proficient in spoken languages.

Home signs are developed naturally as a result of a need to communicate information. When deaf children are unable to hear or speak to convey their needs or wants, or unable to understand the information that is presented to them, it is natural for them to invent another way to communicate.

Home signs are not full languages, however. Since children need full languages for their complete intellectual development, home signs should not be a child's main language. Children who cannot hear need exposure to complete sign languages (such as Kenyan Sign Language).