This four episode podcast series explores the discovery of a sound. It is a faint but distinct sound produced by a fish, the Arctic cod. Only recently have scientists realized how important sound is in the lives of fishes. The Arctic cod was never thought of as a sound producing, or soniferous species, until researchers from the Juanes Lab put a recording device in an Arctic cod tank. The sound they heard was clearly biological, produced by the fish in the tank, and is now known as a 'grunt'. This one discovery launched a multi-year investigation into the sound producing ability of this species. Why do they produce sound? How do they produce sound? When do they produce sound? Is noise pollution interfering with their sound production in the wild? These are the questions this series will dive into, getting accounts from the investigating scientific team, bioacousticians, and fish sound experts. This series also explores noise pollution in the ocean more broadly, and how it is affecting not just fish, but all sound producing marine species.