• Delayed speech development (plain): This is a state in which the child does not speak at the age of three, or it uses speech for communication significantly less than children of the same age. At the same time, understanding spoken language is not impaired, and the child has no deficits in the areas of intellect or motor skills.

The most commonly attributed causes include heredity, delayed maturation of the central nervous system, a mild hearing disorder, or an insufficiently stimulating family environment.

The main symptom is a delay in the area of speech, which can be influenced by suitable education and support. If the educational efforts and the remaining external conditions are suitable, the communication abilities of the child will develop to the expected level.

If, at the age of three, the child does not speak at all, or almost at all, it is suitable to seek the assistance of a specialist (logopedist), who – in cooperation with other specialists (neurologists, phoniatrists etc.) – will exclude other, more serious, causes of the limited expressive abilities of the child.

• Limited speech development: This involves a more significant delay in expression, which is accompanied by further limitations in the development of speech, or extremely unfavorable external circumstances.

Most frequent causes usually include mental retardation, a more severe hearing disorder, or significantly pathologic social environment, which may include even extreme cases of an absence of sensory and communicative impulses (children who are left in their crib for extended periods without interaction with the care-giver, etc.).

Symptoms: This disorder is most apparent in the content aspect of speech (scope and quality of vocabulary, and the ability to use this vocabulary). In children with mental retardation, the degree of the delay depends on the degree of the impairment of intellectual faculties. Even with sufficient educational support at pre-school and school age, the prognosis is unfavorable, in the majority of cases, speech does not develop to a level that would correspond to the norm for the given age.

• Interrupted speech development: This involves a state in which the physiological development of speech was interrupted for some reason.

Causes of the interruption may include injuries, oncological illnesses of the brain or speech organs, severe hearing disorders, significant psychological trauma etc. Under favorable conditions (successful treatment, compensation of the hearing disorder through the use of a hearing aid, injury without permanent damage etc.), the expected level of speech development can be achieved with sufficient support. If it proves impossible to remove the cause of the interruption, or if its consequences are permanent, the further course of development is similar as in the case of limited speech development.

• Interrupted speech development: This involves a state in which the physiological development of speech was interrupted for some reason.

Causes of the interruption may include injuries, oncological illnesses of the brain or speech organs, severe hearing disorders, significant psychological trauma etc. Under favorable conditions (successful treatment, compensation of the hearing disorder through the use of a hearing aid, injury without permanent damage etc.), the expected level of speech development can be achieved with sufficient support. If it proves impossible to remove the cause of the interruption, or if its consequences are permanent, the further course of development is similar as in the case of limited speech development.

• Impaired speech development: We refer to abnormal speech development mostly in cases of children with cleft palates. The abnormality in such cases becomes manifest only in a certain aspect of speech development (most frequently the development of articulation and speech modulation factors).

• Developmental dysphasia: This is a specific speech development impairment, which manifests itself through a diminished ability or inability to learn verbal communication, even though the child has appropriate conditions for the development of speech.

  The causes of this developmental disorder have not yet been identified. It is assumed that they involve minor diffuse damage to the brain, impairing the development of cognitive faculties, which occurred during birth or shortly thereafter. Impact of heredity has also been considered. This diagnosis is made after the 3rd year of the child’s life.

  Symptoms: Deficiencies become manifest both in language and non-language areas. In the area of language, the disorder involves problems understanding spoken language, and at an older age this may also apply to written language. Speech production is also impaired to various extents. The child has problems naming things they would ordinarily know, has problems with grammar (declension, conjugation, use of prepositions) and forming longer sentences. In the non-language area, motor skills tend to be impaired to various extents. The child is generally clumsy, problems can be observed with the speech organs and with hand motor skills. Auditory and visual perception tends to be impaired as well, including memory function, orientation in space and time. The actual composition of problems and the extent of their severity is significantly variable.

  Within comprehensive diagnostics of the child, all particular deficiencies are described in closer detail, and at the same time other causes are excluded (mental retardation, a hearing disorder etc.).