At what age does a child enter the third phase of babbling?

The third phase of babbling typically begins around 7 months of age. This stage is characterized by the production of a wider variety of sounds, which often includes the repetitive consonant-vowel combinations that are crucial for later speech development. This babbling is more complex and varied than earlier phases, leading to the experimentation with pitch and tone. Children begin to express more enthusiasm and emotional intent through their sounds, indicating a growing understanding of communication.

The other age milestones in the options reflect earlier developmental stages. For instance, around 3 months, infants start cooing and making softer, vowel sounds. By 5 months, they may begin to babble, producing some consonant sounds, but their babbling is not yet as varied or complex as what is observed in the third phase. Thus, the correct response accurately identifies the age at which children typically transition into this more advanced stage of language development.