Cetaceans employ diverse acoustic behaviors that vary by species, task, and physiological constraint. Whether these differences reflect symbolic divergence or shared underlying temporal principles remains debated. Hawaiʻi provides a natural experiment in which multiple cetacean species co-occur seasonally within the same acoustic environment. If temporal communication strategies were primarily driven by habitat exposure or social imitation, convergence would be expected under such conditions. Synthesizing passive acoustic monitoring studies spanning multiple species and decades, we examine signal duration, repetition rate, inter-call interval, and bout structure across co-occurring taxa. Despite spatial and seasonal overlap, each species maintains a distinct temporal communication regime aligned with body scale and behavioral objective. No evidence of cross-species temporal convergence is observed under co-presence. These findings support a timing-dominant framework in which temporal structure functions as a constraint-governed control variable conserved within species and task contexts, rather than collapsing under shared environmental exposure.