When a human being repeats what another person has said, this is speech repetition. Although this may sound insignificant, repetition actually plays a vital role in young children's language acquisition. Vocal imitation arises in language development before speech comprehension. Speech repetition begins as early as 12 weeks through what is commonly called babbling. By approximately two years of age, children are creating monologues in which they repeat and manipulate phrases and sentences they've overheard. They use this type of word play to move from repetition to comprehension. The ability to utilize repetition is also important for older children and adults. Continued language development, such as learning new vocabulary or second language acquisition, typically requires the ability to imitate others before language or word acquisition can occur.
In 1874, Carl Wernicke made the assertion that the ability to imitate speech played an integral role in language acquisition. He stated that speech repetition provides the basis for original and longer sentences and that imitating language leads children to analyze the linguistic rules, pronunciation patterns, and conversational pragmatics of speech. When children have this language base, then they can begin to move on to speech perception, or meaning. Children are required to learn, at a very rapid pace, the pronunciation and use of thousands of words. If they cannot utilize speech repetition, according to Wernicke, they cannot learn language.
Two brain cortical processing streams exist to create language acquisition. Speech repetition occurs in the dorsal speech processing stream. This is responsible for mapping sound onto motor representation, otherwise known as speaking. The second cortical process stream is the ventral speech processing stream. It is the ventral stream that is responsible for mapping sound into meaning. The dorsal speech pathway connects the areas of the brain where the dorsal stream and the ventral stream are located. Mirror neurons are usually also introduced when speech repetition is discussed. These are neurons in the brain that fire when an animal acts and observes the same action in another. Therefore, mirror neurons provide a link between repetition and speech perception.
The act of copying the speech of another not only provides humans with the beginnings of language acquisition, but is also the basis for regional dialects, foreign accents, and intonation. Speech repetition is responsible for pitch, timbre, and emotion. It is through repetition that humans know how to deliver language in various forms, such as song, yelling and whispering. Speech repetition often precedes a human's ability to comprehend language and acquire the ability to communicate with others.