**541,000,000:** The longest ago, in years, “that animals acquired some basic sound-making behaviors related to locomotion and predation”
**200,000,000:** The number of years later “before the buzzing of insects started to fill the air”
**230,000,000:** The number of years ago when “vertebrate animals evolved a wide range of vocal abilities”
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¹Footnotes: All items from [scientificamerican.com](https://www.scientificamerican.com/article/fossils-reveal-when-animals-started-making-noise/).
*Originally published in the January 17, 2022, edition of the This Week in Sound email newsletter ([tinyletter.com/disquiet](https://tinyletter.com/disquiet)).*