The world’s oceans are vast, yet humans have disrupted nearly every form of life there — even the lowly oyster. Scientists in France have discovered that oysters respond to sound, and noisy human activity in the ocean is disrupting their natural behavior.

In a study of 32 oysters removed from the ocean environment, scientists were able to determine that oysters responded to sounds between 10 and 1,000 hertz. (The typical range of hearing for a human is between 10 and 20,000 hertz.) While oysters don’t hear as well as we do, they do react to sounds, and typically close their valves when they are stressed or threatened. Oysters don’t have “ears,” but they perceive sounds as vibrations, using an organ called the statocyst, which is present in some aquatic invertebrates.