Humans & AI listening together to save the whales.Orcasound is an open source project that makes it easy to listen live for animals that make sounds, like the endangered orcas in Washington State (USA). We use underwater microphones (hydrophones) deployed in the habitat of the Southern Resident Killer Whales (SRKWs) to listen for the calls, whistles, and clicks they make almost continuously — intense signals that can be heard 10 km away, often before the orcas are visible. Since a Kickstarter in mid-2017, [key members of our community](http://www.orcasound.net/hacker-hall-of-fame/) have built a [web app](live.orcasound.net) that is connected to 3 hydrophones monitoring the SRKW habitat 24/7. Version 2 of the app, launched in May 2020, lets citizen scientists indicate when they detect orca sounds in the live audio data streams, or other sounds that might harm the orcas, like sonar or noise from ships. Orcasound also maintains repositories with other open source tools that support the web app, as well as bioacoustic analysis in general, and killer whale recovery. For example, [orcanode](https://github.com/orcasound/orcanode) holds Python code and shell scripts that generate the live audio stream in lossy HLS format to optimize audio playback within modern browsers and lossless FLAC format for scientific analysis.