The presentation stressed the importance of speech and language in the child's social and personality development; the far-reaching effects of speech and language disorders; the latitude of factors contributing to the various types of such disorders in children; and the therapeutic approach to the child with defective speech. Speech consists of sounds produced by the upper respiratory and alimentary tracts and is described in terms of its phonologic elements (vowels and consonants); vocal pitch, volume and quality; melody and stress pattern; temporal factors of rate, rhythm, duration and phrasing; and expressive gestures. Spoken language is the symbolic use of these sounds. Functions of speech and language are threefold: Emotional expression, self-communication and interpersonal communication. The last, in turn, serves the purposes of social interchange, interchange of information and social control. Disorders of speech and language result in impairment of sociability, communication and effective social control. A child thus handicapped is likely to become socially retarded and psychologically maladjusted. Of high school children in the United States, roughly 5% suffer from some speech defect and over 2,000,000 of them would benefit from special help. Symptomatically, speech and language disorders may be classified into five groups: (1) "articulatory disorders," characterized by substitutions, omissions and distortions of sounds; (2) "cluttering," defined as rapid, dysrhythmic slurring and clustering of sounds; (3) "stuttering," the repetition, prolongation or blocking of sounds and words, often associated with overflow facial grimacing and spasmodic movements of trunk and extremities and, usually, psychologic reactions to stuttering; (4) "voice disorders," ranging from complete absence to abnormalities in quality, pitch, intensity and melody; and (5) "language disorders," subdivided into (a) "delayed speech" (after age 3 years) and (b) "aphasia," resulting from lesions in the central nervous system. An additional group of speech disorders has as etiology some physical abnormalities: (1) "cleft palate speech," with disturbed voice quality and articulation; (2) "cerebral palsy speech," with disturbances in articulation, voice, rhythm and sometimes also delay in language development; and (3) "hearing impairment," which results in improper development of articulation, voice and language.