CAN YOU HEAR ME NOW?

I spotted this tannoy loudspeaker strapped on the side of a building on my way to werk today, why it is there I could not say.

It wasn't making any noise when I went past, but I can't even begin to imagine how loud it would be when turned on!

"It's like people when they say Tannoy when they mean public address system. Tannoy is a brand name." - A. Partridge