Now with more chirping!
A simple experiment in FM audio synthesis.
Outputs a mono audio stream @44.1KHz, (signed) 16 bits per sample.
make; build/birds | aplay -f S16_LE -r 44100 -c 1
Bonus: obfuscated single voice version with LOTS of warnings. Output @22050Hz
make; build/obfuscated_lonely_bird | aplay -f S16_LE -r 22050 -c 1