For our second annual Mystery Sound competition, we’ve rounded up the 20 best sounds from the past year, and invited the hosts of Underunderstood to test their ears in a competitive guessing game. So bust out those Q-tips, turn up your headphones, and prepare to guess along as we find out who will be the ultimate Mystery Sound Champion.

Follow the show on Twitter, Facebook, & Reddit.Subscribe to our Youtube channel here.Become a monthly contributor at 20k.org/donate.If you know what this week's mystery sound is, tell us at mystery.20k.org.Subscribe to Underunderstood wherever you get your podcasts.Get 10% off your first month of BetterHelp at betterhelp.com/20k.Visit zocdoc.com/hertz to download the Zocdoc app and sign up for free.Get your donation of up to $250 matched at givewell.org. Just select "Podcast" at checkout, then enter “Twenty Thousand Hertz.”Episode transcript, music, and credits can be found here: https://www.20k.org/episodes/auralexamLearn more about your ad choices. Visit megaphone.fm/adchoices