Here's a little known fact that has saved me literally minutes of blood boiling. At supermarket self-checkouts, notably Sainsburys, you can turn OFF the annoying voiceover woman shouting repetitive instructions at you through the machine as if you are an utter moron incapable of waving a packet of custard creams over a little glass screen. There is a volume control, bottom left, which gets rid of her. Phew! Made my day to find that out.