Recording Audio to Circular Buffer with Periodic Playback

Hello everyone.

We’ve all used a DVR to rewind a TV show to get in instant replay. I’m looking for a circuit or device that I can use with an audio circuit.

Basically, I want to continuously record the audio from a Fire Department radio system, then press a button to play back what was just recorded. So there could be something like a 10-30 second circular buffer that stores live audio. When a button is pressed, recording stops and the stored audio is played back, then recording continues.

Does anyone know of a circuit or device that can do this? Or is there a shield I can use with an Arduino to accomplish this? If not, maybe this could be something Sparkfun could sell.

Thanks for your help.