Merlin bird sound identification

Merlin, an app by the Cornell Lab of Ornithology, identifies birds based on their songs and calls. The app’s Sound ID feature currently supports 450+ birds in the US and Canada. It works by visualizing an audio recording of a bird’s song or call as a spectrogram — where the x-axis is time, the y-axis is frequency, and each point’s brightness represents decibels, so it’s essentially a monochromatic image — and then classifies it using computer vision. Because the vision model runs on-device, Merlin also works without a cellular connection. Beyond Sound ID, the app also has a Photo ID feature that directly classifies photos of birds, and one that guesses which bird you saw based on three simple questions (how big it was, what its main colors were, and what it was doing) — that last one is probably just some clever filtering though, not an AI model. Links: App Store, Google Play.