Usar "loudspeaker system" en una oración

1. The train manager (manager?!) announces over the loudspeaker system that there is a problem with one of the doors and that we shall be on our way as soon as it is resolved

2. convention over the loudspeaker system

3. She was often chartered for special moonlight cruises, during which an elaborate loudspeaker system piped live music from the observation room throughout the ship