NOEL KING, HOST:
Good morning. I'm Noel King. A zoo in Helsinki, Finland, wanted its monkeys to be comfortable, so researchers let the animals pick what sounds would play in their enclosure. The options were Zen music, falling rain and other sounds from nature and traffic. Turns out the white-faced saki monkeys most often pick that one. They groom each other and fall asleep listening to the sounds of cars and trucks rolling down the highway. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.
