As conveyed in another post, the solution was to simply change a sound setting. However, the qualified Apple Store person determined that it was a hardware problem and swapped your phone. Hmmm, doesn't say much about the Apple line of it is much better to have Apple employees handle device problems than third parties. Lucky your phone was on warranty. Otherwise the Apple employee would have strongly suggested that you buy a new phone due to this "hardware malfunction".I had Apple look at it. They determined that it needed to be swapped out, not me.