During his research career spanning over 40 years, Arthur Popper has had a profound impact on the field of bioacoustics. He studied a broad range of vertebrate taxa, focusing on fish, but also including amphibians, reptiles, and mammals, and published over 200 papers. His work has improved our knowledge of the morphology of vertebrate inner ears and has made significant advances to our understanding of the evolution of vertebrate hearing. In recent years Dr. Popper has focused his research on the important question of how underwater noise impacts aquatic vertebrate hearing. A long standing and fruitful collaboration with his friend and colleague, Richard Fay, has resulted in numerous scientific papers and nearly 60 books including the well-known SHAR-series of the Springer Handbook of Auditory Research.