The rise of affordable acoustic recording units in combination with new developments in machine learning allows us to monitor biodiversity and ecosystem health at previously unimaginable scales. Here I introduce some background to passive acoustic monitoring and show what we can learn from species and soundscapes using Okinawa as a case study. I demonstrate that we can identify species from audio data, and can understand disturbance and resilience of soundscapes using these data. Lastly, I introduce the speakers of our Symposium and the range of topics acoustic ecology can cover.