05-01-2024, 09:50 PM
(05-01-2024, 08:18 PM)Nobby Wrote: Interesting that the Press Gazette article implies that BARB uses audio to identify which channel viewers are watching. I'd not heard that before. There must be loads of examples of channels broadcasting the same or very similar audio.There are two ways it's done. There's audio matching and audio watermarking.
These are described nicely in this glossary:
www.thinkbox.tv
Audio matching takes snapshots of the channels audio and cross references them with what the research panels box has heard.
Audio watermarking is a sub-audible sound added to the channel that identifies it. Barb use a system made by Kantar, the People Meter 7
www.kantar.com
The tones are heard by their software and identify the channel being listened to. There is a phone app that can decipher the sub audible tones. Although of course you need a list of what all the codes mean to make it any use.... otherwise it's just a number!
No idea how the GB News mixup could occur, even if they were using the BBCs pictures the watermarking wouldn't be on it. Unless they were using the BBC off-air, but then the error would have been the other way round.
Possibly it was just using programme audio and they were the same, maybe the fact it was the start of a new day is a factor, it's not often that two channels are broadcasting identical audio at midnight