Like the body size of organisms, the sounds of animals can imply on both their ultimate ('why') and approximate ('how') mechanisms. We use high-precision sound recording systems such as multi-channel microphone array and onboard miniature microphones to sample animal's vocalizations; We use loudspeakers to modify the auditory environment of behaving animals; We program robots that are equipped with microphones, loudspeakers, and other sensors to interact dynamically with behaving animals.