Speech

Speech and language development begins in early infancy and matures throughout a child’s life into adulthood. Both speech and language are essential to connect an individual with the world around them; as such, speech cannot be adequately described without differentiating it from language. Language is the meaning of what an individual understands and the content of the message they communicate during interactions. Language can be communicated to another person through speaking, gestures, text, or even facial expressions and body movements. Speech is just one expression of language through the physical production of sounds. Although speech and language are coupled during typical human development and through the life span, this entry will focus on speech, including typical and atypical development, primary and secondary speech disorders, and the treatment of common speech disorders.

Producing speech is a precise and complex anatomical process, involving coordinated respiration, voicing, and fine motor movements of the speech articulators. Successful speech production requires much more than just moving your lips. To produce a single sound, one must inhale an adequate amount of air to build enough pressure in the lungs to vibrate the vocal folds at a particular frequency to produce voice. Simultaneously, the speech articulators (lips, tongue, teeth, hard palate, velum, glottis) move in a precise way to produce an individual sound, combination of sounds or words.

Individual differences in human anatomy cause the perceptual changes listeners hear in voice and speech during everyday conversations. There is a wide range of what is considered normal speaking, and the criteria to characterize abnormal are indistinct when considering voice, fluency, and speech production. Imagine the differences in listening to the speech of a female toddler, a teenager from the southern United States, or a male adult when considering typical differences in voice and speech production and perception.

The journey to an individual’s first word begins with the first vocalizations made: crying. A caregiver is able to differentiate the infant’s needs and emotional state based on the cries and coos the infant produce in the first months of life. As children move through infancy, they begin to explore sounds and vocalizations beyond cries and coos. They discover their articulators and the power of their own voice. A 6-month-old babbles with early developing speech sounds, including, p, b, m, and w. [Page 2126]The infant laughs, cries, and makes his feelings known with his voice. In Months 7–9, his strings of babbling become longer, more complex, and varied, including more advanced consonant speech sounds, d, n, and t. He will babble to himself and to gain the attention of a caregiver with meaningful and deliberate intonation and prosody to the point where it sounds like he may be having a conversation but without real words. He will begin to imitate his caregiver’s sounds, creating both an opportunity to explore speech sounds but also to build a communicative, rewarding relationship between the caregiver and himself. Around his first birthday, he will use real, understandable words within his speech sound inventory. At 18 months, children typically have approximately 50 words, and at 2 years, they begin putting two words together from their increasing vocabulary.

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