a tall column with four gray loudspeakers in a circle against a clean blue sky. hazard warning system. the possibility of placing

loudspeaker speaker amplification loud horn public alarm warning sound system voice post sky population column call outdoor emergency communication announcement broadcast amplify blue attention background space megaphone wire audio electric information amplifier pillar volume danger mouthpiece communicate tell talk announce bunch blower alert speak shout rusty message hailers emit tall four gray loudspeakers circle clean hazard possibility placing test close sky system