Communication development involves the overall developmental progress in young children in acquiring the ability to comprehend and produce messages that allow them to understand and interact with the social world. Communication development typically progresses from the development of gestural and social pre-linguistic communication to the onset of first words and production and use of language. Children who experience delays in the acquisition of speech and language skills usually follow a typical pattern of development but at a slower rate than children who are not delayed. Marked regression or loss of language can be a sign of a serious underlying medical or neurological problem and may indicate the need for a comprehensive medical, psychological, and audiologic evaluation.
Communication disorders are impairments in the ability to receive, send, process, and comprehend concepts or verbal, non-verbal, and graphic messages. A disorder may be evident in the processes of hearing, language, and/or speech. Individuals may demonstrate one or any combination of these three aspects of communication disorders. Communication disorders in children may be the primary disability or may be secondary to other disabilities
https://www.health.ny.gov/community/infants_children/early_intervention/memoranda/2005-02/eligibility_criteria.htm
Communication disorders are impairments in the ability to receive, send, process, and comprehend concepts or verbal, non-verbal, and graphic messages. A disorder may be evident in the processes of hearing, language, and/or speech. Individuals may demonstrate one or any combination of these three aspects of communication disorders. Communication disorders in children may be the primary disability or may be secondary to other disabilities
https://www.health.ny.gov/community/infants_children/early_intervention/memoranda/2005-02/eligibility_criteria.htm