That Samsung card info says "This microSDHC card has an endurance rating of up to 17,520 hours " That's exactly 2 years of continuos use and are the reason for that odd number of hours. But they don't state at what bit rate. It supports 4k video so that data rate per second compared to a scanners limited audio rate must make a difference. But perhaps it has nothing to do with write cycles, it's only how long the electronics will work. They give a 2 year warranty, perhaps it's somehow related.
/Ubbe