Siri and license plates
February 21, 2025 at 3:49 PM by Dr. Drang
This morning, I went to Swallow Cliff Woods to walk around its trails. As I was driving there and listening to a podcast through CarPlay, an Amber Alert icon appeared on the screen. When I tapped the screen, Siri described a car I was to report if I saw it. There were a couple of weird things about the alert.
First, although this happened a little after 8:00, I later learned that the alert had been canceled more than three hours earlier. So not particularly timely.
Second, the way Siri gave the license plate number of the car was not the way any person would say it. It made me think about Siri rather than the car I should have been looking for (if I’d been driving around four hours earlier). The license plate number was DK97105 and Siri pronounced it
Dee-kay, ninety-seven thousand, one hundred, five
as if it were an actual number, rather than just a string of identifying digits. It was so strange I didn’t really hear anything after “ninety-seven thousand.” I looked it up in notifications before starting this post.
If the string of digits were shorter, a person probably would say them as a number. DK97 would come out as “dee-kay, ninety-seven.” DK971 might be “dee-kay, nine seventy-one,” where you’d think of it as “nine hundred, seventy-one,” but you wouldn’t say the “hundred.” Four-digit numbers would probably come out as a pair of two-digit numbers, with DK9710 being pronounced “dee-kay, ninety-seven, ten.”
I wouldn’t expect Siri to do this, though. The variations from person to person are too great to trust an algorithm to come out with something that sounds natural. The safest solution is for numbers that represent quantities to be pronounced as numbers, and numbers that are merely ID codes to be pronounced as a series of digits—in this case, “dee-kay, nine seven one zero five.”
As is often the case, Siri’s mistake comes from not recognizing context. Apple has given Siri the ability to recognize phone numbers—if you include parentheses or hyphens—and it pronounces them digit-by-digit. But even though the phrase “license plate” was in the alert, Siri treated it as a quantity. Dumb.