Call it "Comunicative Musicality" (as musicologists Malloch and Trevarthan have), or cooing and rocking with baby to calm, or the uplifting melodic line to alert baby, musical sounds and sound effects are the first ways humans related to each other.
As recipients (babies) or providers (parents), we've all experienced it! These sounds grow beautiful over time and nourish our growing musicality, as toddlers and older children. The prosody that is present is something we can return to time and again when we want to make special effects known to each other even as adults.