Unfortunately, searching by sound does not work so well with bird sounds. There are some issues that make it very difficult. Bird calls and songs are more complex than human speech. Not only does every species have a repertory of sounds – no two birds sound alike. Indeed the same species of bird in the same area can have different dialects. Then there is the problem of the device’s microphone, it’s just not up to the job of isolating a bird song from background noise. For that you need a special parabolic mic and a high gain amplifier with filters to remove noise. We expect someday this will be feasible but for now it remains on the wish list for great ideas.