Speech Impairments
(Communication Disorders)
(Information on this web page is provided by the National Dissemination Center for Children
with Disabilities [NICHCY].)


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, intellectual
disability, drug abuse, physical impairments such as cleft lip or palate, and vocal abuse or misuse.
Frequently, however, the cause is unknown.


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
than expressive (speaking) language skills, but this is not always the case.

Speech disorders are 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.

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.

Educational Implications:

Because all communication disorders carry the potential to isolate individuals from their social and
educational surroundings, it is essential to find appropriate timely intervention. While many speech and
language patterns can be called "baby talk" and are part of a young child's normal development, they can
become problems if they are not outgrown as expected. In this way an initial delay in speech and language
or an initial speech pattern can become a disorder which can cause difficulties in learning. Because of the
way the brain develops, it is easier to learn language and communication skills before the age of 5. When
children have muscular disorders, hearing problems or developmental delays, their acquisition of speech,
language and related skills is often affected.

Speech-language pathologists assist children who have communication disorders in various ways. They
provide individual therapy for the child; consult with the child’s teacher about the most effective ways to
facilitate the child’s communication in the class setting; and work closely with the family to develop goals
and techniques for effective therapy in class and at home. The speech-language pathologist may assist
vocational teachers and counselors in establishing communication goals related to the work experiences
of students and suggest strategies that are effective for the important transition from school to employment
and adult life.

Technology can help children whose physical conditions make communication difficult. The use of
electronic communication systems allow people who do not speak and people with severe physical
disabilities engage in the give and take of shared thought.

Vocabulary and concept growth continues during the years children are in school. Reading and writing are
taught and, as students get older, the understanding and use of language becomes more complex.
Communication skills are at the heart of the education experience. Speech and/or language therapy may
continue throughout a student’s school years either in the form of direct therapy or on a consultant basis.

Kinds of speech and language disorders ...

Aphasia        A complex speech and language impairment that results from a stroke or brain injury. It is
more common in elderly people, and young children who develop aphasia are more likely to make a more
full recovery dependent on the nature and extent of brain injury. Aphasia may also occur as a component
of a disease that attacks brain tissue (e.g., tumors, dementia, etc.) There are several types of aphasia:

Difficulty understanding language because of the inability to hear words correctly. Speech may be
understandable, but utterances would be meaningless – words strung together seemingly at random.
Speech may be fluent, but the words may not be real (jargon).
Difficulty speaking. Words are stuttered and halting. Articulation coordination is difficult.
Word-finding problems.
The ability to repeat words, name objects, and understand speech are preserved, but the person cannot
speak spontaneously.
Ability to speak spontaneously and name objects intact, but inability to repeat words.

Aphonia        Literally means “no voice.” This may occur through any injury or condition that prevents the
vocal cords (called “vocal folds” in speech-language pathology), the paired bands of muscle tissue
positioned over the trachea (windpipe) from coming together and vibrating. Aphonia may vary over time,
and may be the result of a cold or flu. Additionally, tumors on the vocal cords would prevent vibrations.
Neurogenic voice disorders (due to nerve or brain damage) include paralysis of the vocal cords;
spasmodic dysphonia – spasms of the vocal cords – may cause them to freeze in an open position.
Neurological disorders such as myasthenia gravis, multiple sclerosis, Parkinson’s disease, and
amyotrophic lateral sclerosis involve gradual destruction of nerve tissue, which may result vocal cord
paralysis. Further, aphonia may occur due to stress, abuse (excessive talking/yelling, smoking,
drinking excessive caffeine or alcohol, exposure to fumes/toxins).

Auditory perceptual processing        (Also called auditory perceptual problem, central auditory
dysfunction or central auditory processing disorder [CAPD]). Difficulty in listening to or
comprehending auditory information, especially under less optimal listening conditions (e.g.,
background noise). Simply, a condition wherein a person does not process speech/language

Developmental articulation disorder        Involves the mispronunciation of speech sounds, for
example, lisping, substituting “w” for “r”, etc. These are common childhood speaking errors, but by
the age of 5 or 6, nearly all speech sounds have been learned by typically developing children.
There are two kinds of developmental articulation disorders: those that occur due to a physical
disability (called “organic”) and those that occur in the absence of a physical disability (called

Organic articulation disorders occur due to some detectable abnormality, such as hearing loss,
cleft lip, and cleft palate. Children who have congenital hearing loss will have difficulty learning to
speak, and their speech may be imprecise, unusual in pitch, and nasal sounding. Children with
frequent middle ear infections may have similar problems.
Functional articulation disorders are not due to a physical abnormalities, but have problems
hearing sounds properly and/or producing sounds to match adult speech. Over there is a chart of
the typical order of speech sound mastery in children. Keep in mind that children are wildly diverse
in their development.

Language delay        A condition wherein a child does not learn language as quickly as his/her peers.
This child may have normal intelligence, or he/she may have a condition involving intellectual
disability or a language delay. Developmental language disorders in the absence of intellectual
disability or any other impairment may be hereditary, or genetic. Also developmental language
disorder may be the result of hearing loss. Children with developmental language disorder learn
language in the same sequence as their peers, but the pace is delayed. Developmental language
disorders (vs. a delay, which resolves with or without treatment) never “go away”, and they will
always be a part of a person’s life. (Also called
Developmental Language Disorder.)

Dysarthria        (Also called SLURRED SPEECH.) Involves disturbances in control over speech
muscles. Thus dysarthria is grouped in the category of motor speech or speech motor disorders.
Dysarthria occurs due to impairment or damage to the nervous system (brain, spinal cord, nerves).
The speech muscles themselves may be impaired, weak or paralyzed, or the areas of the brain
responsible for coordinating their function may be affected or damaged. This disorder could also
occur due to tumors in the nervous system or a traumatic brain injury. Degenerative diseases such
as Parkinson’s disease, amyotrophic lateral sclerosis, dementia, Huntington’s chorea, syphilis, and
other neurological diseases are other causes of dysarthria. This can be seen in children due to
paralysis, weakness, altered muscle tone, or incoordination of the muscles used in speaking.
Conditions such as cerebral palsy can cause this. There are many kinds of dysarthria, based on
the site of the lesion (damage).

FLACCID DYSARTHRIA involves muscle weakness and loss of muscle tone. This person’s
speech is breathy, weak, lacking in intonation, and has imprecise consonants. Reflexes are absent.
SPASTIC DYSARTHRIA involves excessive muscle tension and overly sensitive reflexes.
This person’s voice often sounds strained or strangled, and reflexes are so easily excited that these
extraneous movements interfere with speech production.
ATAXIC DYSARTHRIA involves difficulty in coordinating the rate, range, and force of speech
movements. This person may over or undershoot the appropriate positions of the articulators (lips,
tongue, jaw) in speech.
HYPERKINETIC DYSARTHRIA involves a loss of inhibitory (stopping, halting, slowing)
control – thus, abnormal, involuntary movements interrupt speech. These may occur in the form of
tremors, tics, athetosis (writhing movements), or dystonia (movement to an extraneous posture and
momentary freezing in that position).
HYPOKINETIC DYSARTHRIA involves lack of movement, usually caused by Parkinson’s

Stuttering or stammering        A complex fluency disorder of speech affecting the smooth flow of
words, which may involve repetition of sounds or words, prolonged sounds, facial grimaces,
muscle tension, and other involuntary physical movements; hesitations, repetitions, omissions, or
extra sounds in speech patterns. It is believed that childhood stuttering is caused by an interaction
of neurological (within the brain), environmental, and developmental factors.

Voice disturbances        These may occur for a variety of reasons. Any change in the shape or
functioning of the vocal cords will cause a voice disturbance. The vocal cords sit above the
trachea, and air from the lungs cause them to vibrate, producing the sounds of one’s voice. There
are five categories of conditions that can interfere with vocal cord vibration:
Structural changes of the vocal cords. Growths such as nodules, polyps, cysts, papilloma,
or granuloma growths or malignant growths can distort the straight edges of the cords.
Neurogenic voice disorders, caused by brain/nervous system damage or malfunction, include vocal fold paralysis, vocal tremor, and spasmodic
dysphonia which can interfere with normal vibrations. Neurological diseases such as myasthenia gravis, multiple sclerosis, amyotrophic lateral
sclerosis, and Parkinson’s disease can paralyze the vocal cords.
Diseases such as respiratory infections, allergies, and esophageal reflux disorder can cause swelling of the vocal
cords and prevent normal vibration.
Vocal abuse (excessive/loud talking, excessive caffeine or alcohol intake, lack of water consumption, exposure to fumes smoking, etc.) can cause
swollen vocal cords or growths on the folds.  
Idiopathic voice disorders (unknown origin)

Verbal dyspraxia        A motor speech disorder, also called apraxia, verbal apraxia, and developmental verbal dyspraxia. A child with verbal dyspraxia
has difficulty producing sounds, syllables, and words because they cannot consistently find the correct placement for the structures of speech (e.g.,
lips, tongue, jaw). This affects their ability to say certain sounds/sound combinations and sequence the sounds into words and sentences. This is
neurologically based. It can be present at birth or acquired due to brain damage.

Ankyloglossia        Sometimes called “tongue-tied,” the skin under the tongue (lingual frenulum) is shorter and wider than normal and restricts distinct
sounds to be made. In infants, this may result in potential feeding problems.
Terminology that might be useful here ...

Speech        The audible, oral output of language.

Language        A socially shared, rule-governed code used for communication. It is not limited to oral expression, however – it occurs in written form,
through the use of gestures , alternative methods of communication for those who are low verbal or nonverbal, and within one’s own thoughts.

Speech disorders        Difficulties producing speech sounds or problems with voice quality; abnormal speech that is unintelligible, unpleasant, or
interferes with communication and includes problems of voice, speech clarity, or fluency (stuttering).

Language disorders        Difficulty or inability to master language systems, their rules, or applications, which interferes with communication.

Receptive language disorders        Difficulties in comprehending what others say.

Expressive language disorders        Difficulties in producing language.

Fluency disorder        Speech disorder in which hesitations during speech interfere with communication.

Cluttering         A speech disorder characterized by excessively rapid, disorganized speaking, often including words or phrases unrelated to the topic.

Delayed speech        Deficit in speaking proficiency whereby the individual performs like someone much younger.

Articulation        Movement of the tongue, teeth, lips, and palate to produce the sounds of language.

Articulation errors or problems        Abnormal production of speech sounds; speech problems such as omissions, substitutions, additions, or
distortions of words; or speech sounds that are inconsistent with the native language (usually a temporary developmental irregularity).

Cleft lip        A congenital condition characterized by incomplete closure of the upper lip that may affect speech and nutrition and can be closed with

Cleft palate        A congenital split in the palate that results in an excessive nasal quality of the voice and can affect speech and nutrition. It can be
repaired by surgery or a dental appliance.

Malocclusion        A condition in which the upper and lower teeth do not meet properly.

Voice disorder        A condition in which an individual habitually speaks with a voice that differs in pitch, loudness, or quality from the voices of others
of the same sex and age in a particular cultural group.

Speech/language pathologist (SLP)        A specialist who diagnoses and treats or remediates communication disorders in children. The SLP provides
individual therapy for children, consults with the child’s teachers about the most effective ways to facilitate the child’s communication in the class
setting, and works closely with the family to develop goals and techniques for effective therapy in class and at home.

AGE                                         SOUNDS MASTERED
2-3                                        p, m, h, n, w, b, k, g, d, t, ng  
3-4                                         f, y                                           
4-5                                         r, l, s                                        
5-6                                       ch, sh, z, j, v, th                    
6-7                                       th                                          
7-8                                       zh