I have purchased the MC Power/Audio cable for my new 2720 thinking that the "other" connection on the cable was for audio. I had hoped to connect a speaker to it and mount the speaker on the bike somewhere. But alas, it looks like I have a problem. Can someone tell me if in fact this is an audio output, and do I need to plug in something else to get "Mabel" to talk? It will not be a great loss if she won't speak as I needed the power cable anyway, but I would like to have the option.