 Peter Lloyd Tyak is a professor of marine mammal biology at the Scottish Oceans Institute at the University of St Andrews in Scotland. Professor Tyak is the world's leading expert on the influence of anthropogenic noise on behavior and echolocation in marine mammals. Professor Tyak has had close ties to Orhus University for almost 30 years. AU scientists have collaborated with him on several joint grants and numerous joint publications, and AU and St Andrews regularly exchange students and postdocs to give them the best training from both labs. My research has shown that whales and dolphins can learn to produce new sounds when they hear arbitrary sounds. And when we learn language and music, we do the same thing. We learn the sounds around us, but most mammals inherit pattern generators in their nervous system that make species-specific sounds. So for example, I've shown that Hupback whales learn the songs they sing during the breeding season, and I've also shown that dolphins learn to produce individually distinctive whistles, and they can even copy the whistle of a partner to call it. And there's a lot of work now testing how referential this calling is, where the dolphins actually name each other. I first heard about Arhus when I read a paper by Professor Bertle Mowell several decades ago, when he predicted that sperm whales should have a powerful directional sonar beam. My colleagues at the Woods Hole Oceanographic Institution at that point who are observational biologists had recorded clicks from sperm whales at all angles, so they thought these clicks were used for communication and were not well suited for echolocation. But what excited me about the Arhus work was that Mowell used his knowledge of functional anatomy, the structure of how sperm whales make sound, and acoustic theory to make really clear predictions about how the sperm whale signal should be produced for echolocation and how you can test for directionality. Some activities at sea have gone up a lot over the last decades. With that, we also face increasing noise levels at sea, and whales are potentially vulnerable to those increasing noise levels. Professor Peter Tyak has been a pioneer in developing techniques to understand the effects of these noise levels. In particular, he's been the co-inventor of this device that's called the D-Tag that can be placed on the skin of whales, and with which we can record received noise levels on the animals, and also quantify the effects of these noise levels on their forging and their capability to talk to each other out in the open ocean. I work quite closely with Professor Madsen on developing new ways to study the neural processing of the signals that whales and dolphins make. I've developed a set of non-invasive neurobiological sensors on tags, and we're testing these on purposes at Jordan Belt in Karedeminda in order to understand how toothed whales perceptually organize all the echo information to solve their complex biosonar tasks.