Source Coding With a Listening-Helper

We consider the cooperative coding of a pair of correlated memoryless source and side-information sequences wherein an encoder assisted by a side-information aided listening-helper describe the source and side-information to a receiver. We obtain a single-letter characterization of the rate region in both cases: when the decoder reconstructs just the source and when it reconstructs both the source and side-information. In the quadratic Gaussian setting we determine the optimal law characterizing the rate region using a technique introduced by Courtade in combination with a conditional version of the converse for the Gaussian CEO problem.