Sound-based pistachio sorter

We hate getting those pistachios that can't be opened without a hammer, and neither does Tom Pearson, who created a sound-based pistachio sorter that listens to the sound the nuts makes when falling into a steel plate, detects whether they're open or not, and whooshes the unopened ones away with a blast of air. His sorter is 97% accurate, which means you're still going to be annoyed every once in awhile. It's just that'll be less than you are right now, since current sorters only have a 90% accuracy rate.