I must admit that I rather skipped over the first reference, but when I came upon it a second time, I found myself stopping to sort it out:
"The rhythms of the London underground: shrill beeps, a brief flicker of the lights as they pass out of the station, something incomprehensible on the tannoy." (page 308).
Something about the way it was written made me think at first that the tannoy was the platform and that the character in question was referring to an object. But a second go made me realize that the tannoy was some kind of sound system or loudspeaker. If I'd paid more attention the first time, though, I would have known this already:
"...the tannoy playing a recorded announcement on the unmanned station platform"(page 90).
Tannoy Ltd. is a Scotland based company that was started in London and is now owned by the Danes. Or a Danish group anyway. The word is an acronym of the words "tantalum alloy" which was the metal used in an electrolytic rectifier (don't worry, we're not going down that particular road today) and the reason Wikipedia gives for it becoming a household name is that it was the supplier of PA systems to the troops during World War II, and subsequently to British holiday camps, as well as providing amplifiers for home use.
|Yes, that's none other than Cyril Ritchard, aka Captain Hook!|
Tannoy is kind of an odd word for a public address system, considering that I don't have the impression that the metal itself is even used in the loudspeakers, though I could be wrong. On the other hand, "loudspeaker" is a kind of odd word too, when you start to listen to it. It seems a bit obvious and ponderous, but then I guess many English words do, once you break them down.