3000: Total number of individual tourists allowed each year at Kronotsky Nature Reserve on the Russian coast
30.6: Decline, in decibels, of noise pollution in Mumbai, India, between 2015 and 2021
30: Rough estimate, in millions of U.S. dollars, to treat “Havana syndrome,” allocated out of a $768 billion defense spending bill signed into law by President Joe Biden
▰ ▰ ▰
Update: I accidentally left out the word “millions” in the Havana entry when I first published this. And I added the word “allocated” for clarification.
Originally published in the January 3, 2022, edition of the This Week in Sound email newsletter (tinyletter.com/disquiet).