For human beings the most common method of communication is by speaking to one another. We speak using our voices and interacting with other people, who for the most part, speak the same language. When two different languages are put into one conversation it may make communicating difficult but not impossible.
There are things that make communicating much more difficult than just having a language barrier. There are many people who have "an impairment in the ability to receive, send, process, and comprehend concepts or verbal, nonverbal and graphic symbols systems." This difficulty in communication is known as a communication disorder. More specifically, a person who has "a communication disorder, such as stuttering, impaired articulation, or a voice impairment that adversely affects a child's educational performance" is someone who has a speech impairment.
There are three basic types of speech impairments. The first is when a person continuously creates errors in the construction of their speech sounds; this is known as articulation disorders. The second basic type is fluency disorder which is when someone is having a hard time with the flow or the rhythm of speech. Finally, the third type is when there is a problem with the quality or use of one's voice, which is known as a voice disorder.
Communication disorders, more specifically, speech impairments have several different causes. Dysarthria for example refers to a group of speech disorders that are caused by several motor control impairments. According to Medterms, Dysarthria...