During Halloween in Indianapolis, the Acoustical Society of America held a special session titled “Acoustic Trick-or-Treat: Eerie Noises, Spooky Speech, and Creative Masking.” One of the talks in this session was by Miriam Kolar of Amherst College, and she talked about the special acoustics in a 3000-year-old ceremonial center, known as Chavín de Huántar, in the Peruvian Andes. The acoustic phenomena observed at the site might have been interpreted as an embodiment of the instruments played during ceromonies or an intervention by a higher power. Read the full article at Physics Today or visit the project’s website.