Speech and language disorders refer to problems in communication and related areas such as oral motor function. These delays and disorders range from simple sound substitutions to the inability to understand or use language or use the oral-motor mechanism for functional speech and feeding. Some causes of speech and language disorders include hearing loss, neurological disorders, brain injury, mental retardation, drug abuse, physical impairments such as cleft lip or palate, and vocal abuse or misuse. Frequently, however, the cause is unknown.
More than one million of the students served in
the public schools’ special education programs
in the 2000-2001 school year were categorized as
having a speech or language impairment. This
estimate does not include children who have
speech/language problems secondary to other
conditions such as deafness. Language disorders
may be related to other disabilities such as
mental retardation, autism, or cerebral palsy.
It is estimated that communication disorders
(including speech, language, and hearing
disorders) affect one of every 10 people in the
United States.
A child's communication is considered delayed when the
child is noticeably behind his or her peers in
the acquisition of speech and/or language
skills. Sometimes a child will have greater
receptive (understanding) than expressive
(speaking) language skills, but this is not
always the case.
Speech disorders refer to difficulties producing speech
sounds or problems with voice quality. They
might be characterized by an interruption in the
flow or rhythm of speech, such as stuttering,
which is called dysfluency. Speech disorders may
be problems with the way sounds are formed,
called articulation or phonological disorders,
or they may be difficulties with the pitch,
volume or quality of the voice. There may be a
combination of several problems. People with
speech disorders have trouble using some speech
sounds, which can also be a symptom of a delay.
They may say "see" when they mean "ski" or they
may have trouble using other sounds like "l" or
"r." Listeners may have trouble understanding
what someone with a speech disorder is trying to
say. People with voice disorders may have
trouble with the way their voices sound.
A language disorder is an impairment in the ability to
understand and/or use words in context, both
verbally and nonverbally. Some characteristics
of language disorders include improper use of
words and their meanings, inability to express
ideas, inappropriate grammatical patterns,
reduced vocabulary and inability to follow
directions. One or a combination of these
characteristics may occur in children who are
affected by language learning disabilities or
developmental language delay. Children may hear
or see a word but not be able to understand its
meaning. They may have trouble getting others to
understand what they are trying to communicate.
- National Dissemination Center for Children with Disabilities (NICHCY)



