This project video from Steve Hyde shows us his pi powered dog bark echo machine in action:
We built a dog repeater to bark back when dogs bark. It uses a Raspberry Pi computer and a Sound to Light board. The device connects to my stereo amplifier and plays dog barks through outdoor speakers on our patio
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!