When a chicken speaks, it's hard to tell whether it's a happy or sad cluck. That's what a research team at Georgia Tech is trying to decipher by recording more than 1,000 hours of chickens clucking.
ROBERT SIEGEL, HOST:
Any preschooler knows what a chicken sounds like.
(SOUNDBITE OF CHICKEN CLUCKING)
SIEGEL: The question is what does all that clucking mean?
MELISSA BLOCK, HOST: