What language acquisition stage involves infants playing with the pitch and volume of their vocalizations?

The babbling stage is characterized by infants experimenting with the sounds they can produce, including variations in pitch and volume. During this stage, which typically occurs around six to eight months of age, infants begin to make repeated syllable sounds (like "ba-ba" or "da-da") and start to explore the range of their vocal capabilities. This playful experimentation with sound is an essential part of language development, as it helps infants develop the control and coordination needed for future speech.

In contrast, telegraphic speech refers to a later stage of language acquisition where children use short, simple phrases that typically consist of just key content words, omitting less critical elements, which usually occurs around two to three years of age. The two-word stage involves combining two words to form simple sentences, demonstrating early syntax and greater linguistic understanding. The holophrastic stage precedes telegraphic speech and involves single words or phrases conveying entire thoughts or ideas, usually occurring between one and two years of age. Therefore, the babbling stage is distinctly focused on sound play rather than word formation or sentence structure.