Earth's sounds
Many of these ocean-dwelling ancients evolved sophisticated sensors for light, sound, and chemicals. But, as far as we know, they did not communicate by sound. It would take about another 200 million years or more for animals to call or sing.
Why did sonic communication take so long to blossom? We do not know for sure, and paleontologists may yet discover fossils of ancient sound makers, but it’s also possible that the keen ears of listening predators muzzled life’s sonic evolution. All of the early animal predators — arthropods and fish especially — could detect vibrations in water or, later, tremors in the soil on land. To cry out was to invite death.
No creatures sang when the seas first swarmed with animal life or when the oceans’ reefs first rose. Primeval forests contained no trilling insects or chorusing vertebrate animals. For more than nine-tenths of its history, Earth lacked any communicative sounds. Animals signaled only by catching the eye of another, or through touch and chemicals.