A language delay is language development that is significantly below the norm for a child of a specified age.
Language delay is a communication disorder, a category that includes a wide variety of speech, language, and hearing impairments. The milestones of language development, including the onset of babbling and a child's first words and sentences, normally occur within approximate age ranges. However, individual children vary enormously regarding the exact age at which each milestone is reached. There also are different styles of language development. Most children have acquired good verbal communication by the age of three. But one child may be wordless until the age of two and a half and then immediately start talking in three-word sentences. Another child might have several words at ten months but add very few additional words over the following year. Other children start talking at about 12 months and progress steadily.
Language delay usually becomes apparent during infancy or early childhood. Any delay in general development usually causes language delay. Children with language delay may acquire language skills in the usual progression but at a much slower rate, so that their language development may be equivalent to a normally developing child of a much younger chronological age. Maturation delay, also called developmental language delay, is one of the most common types of language delay. Children with a maturation delay may be referred to as "late talkers" or "late bloomers." Maturation delays frequently run in families.
Speech/language delay is the most common developmental disorder in children aged three to 16 years, affecting approximately 3 to 10 percent of children. It is three to four times more common in boys than in girls.
Causes and symptoms
Common nonphysical causes of language delay include circumstances in which the following are the case:
- The child is concentrating on some other skill, such as walking perfectly, rather than on language.
- The child has a twin or sibling very close in age and thus may not receive as much individual attention.
- The child has older siblings who interpret so well that the child has no need to speak or whose talk is so continuous that the child lacks the opportunity to speak.
- The child is in a daycare situation with too few adults to provide individual attention.
- The child is under the care of a non-English speaker.
- The child is bilingual or multilingual, learning two or more languages simultaneously but at a slower speed; the child's combined comprehension of the languages is normal for that age.
- The child suffers from psychosocial deprivation such as poverty, malnutrition , poor housing, neglect, inadequate linguistic stimulation, emotional stress.
- The child is abused; abusive parents are more likely to neglect their children and less likely to communicate with them verbally.
Language delay may result from a variety of underlying disorders, including the following:
- mental retardation
- maturation delay (This delay in the maturation of the central neurological processes required to produce speech is often the cause of late talking.)
- hearing impairment
- dyslexia , a specific reading disorder which may cause language delay in preschoolers
- a learning disability
- cerebral palsy, in which numerous factors may contribute to language delay
- autism, a developmental disorder in which, among other things, children do not use language or use it abnormally
- congenital blindness, even in the absence of other neurological impairment
- brain damage
- Klinefelter syndrome, a disorder in which males are born with an extra X chromosome
- receptive aphasia or receptive language disorder, a deficit in spoken language comprehension or in the ability to respond to spoken language, resulting from brain damage
- expressive aphasia, an inability to speak or write, although comprehension is normal; caused by malnutrition, brain damage, or hereditary factors
- childhood apraxia of speech, a nervous system disorder
Mental retardation accounts for more than 50 percent of language delays. Language delay is usually more severe than other developmental delays in retarded children, and it is often the first noticeable symptom of mental retardation. Mental retardation causes global language delay, including delayed auditory comprehension and use of gestures.
Impaired hearing is one of the most common causes of language delay. Any child who does not hear speech in a clear and consistent manner will have language delay. Even a minor hearing impairment can significantly affect language development. In general the more severe the impairment, the more serious the language delay. Children with congenital (present at birth) hearing impairment or hearing loss that occurs within the first two years of life (known as prelingual hearing loss) experience serious language delay, even when the impairment is diagnosed and treated at an early age. However, deaf children born to parents who use sign language develop infant babble and a fully expressive sign language at the same rate as hearing children.
Symptoms of language delay
Symptoms of language delay include the following:
- failure to meet the developmental milestones for language development
- language development that lags behind other children of the same age by at least one year
- inability to follow directions
- slow or incomprehensible speech after three years of age
- serious difficulties with syntax (placing words in a sentence in the correct order)
- serious difficulties with articulation, including the substitution, omission, or distortion of certain sounds
Language delays resulting from underlying conditions may have symptoms specific to the condition. Nonetheless, specific symptoms of language delay may include the following:
- not babbling by 12 to 15 months of age
- not understanding simple commands by 18 months of age
- not talking by two years of age
- not using sentences by three years of age
- not being able to tell a simple story by four or five years of age
Symptoms of language delay with mental retardation
Mentally impaired children usually babble during their first year and may speak their first words within the normal age range. However, they often cannot do the following:
- put words together
- speak in complete sentences
- acquire a larger, more varied vocabulary
- develop grammatically
Mentally impaired children in conversation may be repetitive and routine, exhibiting little creativity . Nevertheless vocabulary and grammatical development appear to proceed by very similar processes in mentally retarded and developmentally normal children.
In general the severity of language delay depends on the severity of the mental retardation. Levels of retardation and language skill are ranked as follows:
- mild retardation ( intelligence quotient [IQ] range of 52–68): usually eventually develop language skills
- moderate retardation (IQ range of 36–51): usually learn to talk and communicate
- severe retardation (IQ range of 20–35): have limited language but can speak a few words
Language delays among mentally retarded children vary greatly. Some severely mentally impaired children who also have hydrocephalus or Williams syndrome may acquire exceptional conversational language skills, sometimes called the "chatterbox syndrome." Some children (called savants) test as mentally retarded but learn their native language, as well as foreign languages, very easily. With Down syndrome and some other disorders, language delay is more severe than other mental impairments. This factor may be due to the characteristic facial abnormalities and relatively large tongues of Down-syndrome children. Children with Down syndrome also are at higher risk for hearing impairment and ear infections that cause hearing loss.
Symptoms of language delay with other disorders
Symptoms of language delay in a hearing-impaired child include the following:
- babbling at an older-than-normal age
- babbling that is less varied and less sustained
- first words at age two or older
- only two-word sentences by age four or five in a profoundly deaf child
Dyslexic children have difficulty separating parts of words and single words within a group of words. Symptoms of dyslexia may include:
- poor articulation
- difficulties identifying sounds within words, blending sounds, or rhyming
- difficulty putting sounds in the correct order
- hesitation in choosing words
A learning-disabled child usually exhibits an uneven pattern of language development. In addition, about 50 percent of autistic children never learn to speak. Those who do speak often have severe language delay and may use words in unusual ways. They rarely participate in interactive dialogue and often speak with an unusual rhythm or pitch. The speech of some autistic children has an atonic or sing-song quality.
Children with congenital blindness average about an eight-month delay in speaking words. Although blind children develop language in much the same way as sighted children, they may rely more on conversational formulas.
The speech of children with receptive aphasia is both delayed and sparse, ungrammatical, and poorly articulated. Children with expressive aphasia fail to speak at the usual age although they have normal speech comprehension and articulation. Children with defined lesions in language areas on either side of the brain have initial but quite variable language delays. Usually their language catches up by the age of two or three without noticeable deficits.
Apraxia affects the ability to sequence and vocalize sounds, syllables, and words. Children with apraxia know what they want to say, but their brains do not send the correct signals to the lips, jaw, and tongue to form the words. In addition to language delay, apraxia often causes other expressive language disorders .
When to call the doctor
Children who are not talking at all by the age of two should have a complete developmental assessment . Children who are not progressing in word-learning skills by the end of the first grade should be tested for dyslexia.
Diagnosis of language delay requires a complete physical examination and a thorough developmental history, with special attention to language milestones. In young children it may be very difficult to distinguish between a late talker and a developmental expressive disorder. The diagnosis often is made by a speech/language pathologist. Language performance of bilingual children must be compared to that of other bilingual children of a similar cultural and linguistic background. Generalized delay in all developmental milestones suggests mental retardation.
Numerous tests are used to screen for language delay and assess language development. Some of these are described below:
- The Denver Developmental Screening Test is the most popular test in clinical use for children from birth to six years of age. Since language delay is the most common early symptom of global intellectual impairment, the test provides a comprehensive developmental assessment.
- The Early Language Milestone Scale is a simple tool for assessing language development in children under the age of three. It relies on parents' reports and a very short test focusing on visual, receptive, and expressive language.
- The Mullen Scales of Early Learning is a comprehensive assessment of language, motor, and perceptual abilities in children from birth to five years eight months of age.
- The Peabody Picture Vocabulary Test, for children aged two-and-a-half to 18 years, is a useful screening instrument for word comprehension.
- The Receptive One-Word Picture Vocabulary Test provides information about a child's ability to understand language.
Other tests for language delay include:
- Early Speech Perception Test
- Assessing Prelinguistic and Early Linguistic Behaviors in Developmentally Young Children
- Joliet 3-Minute Preschool Speech and Language Screen
- Fluharty Preschool Speech and Language Screening Test
- Assessment of Fluency in School-Age Children
- Children's Articulation Test
- Clinical Evaluation of Language Fundamentals
- Phonological Assessment of Child Speech (Initial assessment may indicate the need for additional testing to identify underlying physical conditions.)
About 60 percent of language delays in children under age three resolve spontaneously. Early detection and intervention for language delay can help prevent social, cognitive, and emotional problems. Treatment of language delay is individualized for each child with the primary goal of teaching the child strategies for comprehending spoken language and producing appropriate linguistic or communicative behavior. Depending on the type and cause of the delay, the healthcare team may include a physician, a speech/language pathologist, an audiologist, a psychologist, an occupational therapist, and a social worker. Psychotherapy may be recommended if the language delay is accompanied by anxiety or depression. Speech therapy is used to help mentally impaired children develop intelligible language. Behavior therapy may help autistic children progress in speech acquisition.
Hearing-impaired children who are identified and receive early intervention before six months of age develop significantly better language skills than children identified after six months of age. Early, consistent, and conscious use of visual communication modes such as sign language, finger spelling, and cued speech, and/or hearing amplification and oral training can reduce the language delay. Since only about 10 percent of deaf children are born to deaf parents, hearing parents can promote their deaf child's language development by learning and using sign language. Many types of hearing aids are available for children as young as three months. Cochlear implants may be used for profoundly deaf children aged two to six. These children usually develop better language skills than those with hearing aids or other devices.
With appropriate intervention language-delayed children usually catch up with their peers. Children with maturation delay usually have normal language development by the time they enter school. Although a bilingual home environment can cause a temporary language delay, most children become proficient in both languages before the age of five. Nevertheless, early language delays may cause problems with behavior and social interactions. A language delay can lead to elective mutism , a condition in which children choose not to speak. Such children typically speak when they are on their own, with their friends, and sometimes with their parents; however, they will not speak in school, in public situations, or with strangers.
Most mentally retarded children eventually develop at least some degree of language. But frustration and anger at their inability to communicate effectively can lead to numerous social and behavioral problems. An adolescent with Down syndrome and an IQ of about 50 may speak at the grammatical level of an unaffected three-year-old, with short, repetitive, simple sentences. Nevertheless, Down-syndrome children often are very sociable and interested in conversational language.
Children who receive early intervention for hearing impairments can develop at nearly the same rate as other children. However, depending on the severity of their hearing loss, they may continue to have difficulties with articulation and speech quality as well as with written language. Children who lose their hearing after the first few years of life have far fewer language delays than children who are deaf from birth or who lose their hearing within the first year.
Most children with receptive aphasia gradually acquire a language of their own, understood only by those close to them. Children with expressive aphasia will not develop normal language skills without intervention and are at risk for language-based learning disabilities.
There are no known preventions for most language delays. Prenatal care and good nutrition during pregnancy and early childhood may help prevent some expressive language delays. Hearing-impaired children who use sign language within their families usually have no signed-language delay.
A speech/language pathologist can teach parents methods for encouraging and enhancing their child's language development. Special programs also are available for helping language-delayed children and their parents. Parents, caregivers, and teachers of children with language delay should take the following steps:
- adjust their speech to the child's level
- use consistent language
- use meaningful language
- repeat words, phrases, sentences, and stories
- use small-group instruction
Apraxia —Impairment of the ability to make purposeful movements, but not paralysis or loss of sensation.
Expressive aphasia —A developmental disorder in which a child has lower-than-normal proficiency in vocabulary, production of complex sentences, and word recall, although language comprehension is normal.
Maturation delay —Developmental language delay; a language delay caused by the slow maturation of speech centers in the brain; often causes late talking.
Receptive aphasia —A developmental disorder in which a child has difficulty comprehending spoken and written language.
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Margaret Alic, PhD