As the rocks sniffed at a wave, Bill François noticed something shimmering in the water. The glimmer immediately caught his attention. It was a sardine, perhaps lost or chased by tuna. He gently picked it up and studied this gift from the sea. Its eyes seemed to speak volumes. Its silence suggested it held many secrets to share about this blue world, a world he had never before approached. Its presence sparked his curiosity and awakened his awareness. Suddenly, he was no longer the person who feared the deep; its mysteries captivated him. He began exploring the depths of the sea, enchanted by every creature that told him its own story. How do fish communicate? How do they perceive the world? Are their lives and feelings similar to ours as humans? This desire to uncover these secrets drove the author of this book, marking the beginning of his journey as a fish scientist. In this book, we embark on a new journey to explore the world of the sea, discovering many fascinating answers and new questions that will transform our understanding of both the ocean and the human world. The sea is a vast realm, brimming with mystery, secrets, and a cacophony of sounds, much of which remains unknown. It is even more saturated with noise than the air we breathe. These are sounds we cannot perceive or hear from the shore. Let us delve into the depths of this book and learn more about the nature of this noise, as the author explains it to us.