Sounds produced by animals are often very apparent to humans, indeed in some instances these sounds are the only indication of the presence of the animal. Sound is also a key channel of communication between animals and can play a role in orientation, navigation and prey capture. These factors mean that bioacoustics can be a useful tool in several contexts from census and monitoring roles in conservation, through indications of welfare status to the impacts of anthropogenic noise. The same factors mean that an understanding of aspects of bioacoustics is important in pure research, i.e. research addressing fundamental questions. Despite this obvious commonality there is relatively little interaction between pure and applied aspects of bioacoustics. This talk will seek to redress the balance using examples drawn from acoustic communication, conservation and anthropogenic noise.