Which developmental milestone typically occurs around 2-4 months of age?

At around 2-4 months of age, infants typically begin to produce grunts and sighs, which can indicate comfort and contentment. This vocal development is an important part of early communication as it reflects the infant's emotional state and their growing ability to engage with their environment. At this stage, the sounds they make are not yet linguistically structured but serve as a precursor to more complex vocalizations.

The other options represent milestones that occur at different stages of development. For example, first laughter typically occurs a bit later, around 3-4 months, as children start to engage in social interactions. Canonical babbling, which includes repetitive consonant-vowel combinations, usually begins around 4-6 months, indicating a more advanced stage of vocal development. Similarly, the use of consonant-vowel combinations, where infants start to produce more structured sounds, typically occurs after the initial stage of grunting and sighs, making it a later milestone. Understanding these timelines helps caregivers and educators support appropriate language development in infants.