I just returned from riding three LD trains in July-August---the CS, EB, and SWC. In at least one case(CS) and I think in the others only the speakers in the hall work anymore. And in the case of the CS you could not hear the announcements unless you left your door open since the volume was too low. I LIKE hearing the announcements so I would complain that I had trouble hearing the announcements instead of requesting the ability to turn them off. There is so much other ambient noise like the train movements, rattles, etc, why would the announcements be an intrusion. You cannot turn off the announcements on other public transportation such as airliners(even in international lie flat first class), and buses.
I vote YES for the public announcements even when the cafe guy is opening and closing the cafe snack bar.