This is a very British way of saying, “I didn’t hear what you said–please repeat.” The OED dates it to the mid-sixties, and it was still novel enough in 1972 for Tom Stoppard to have sport with it in his play “Jumpers”:
Miss Moore, is there anything you wish to say at this stage?
Dotty (in the sense of “Pardon?”): Sorry?
Bones: My dear, we are all sorry—
I’ve felt for a while Sorry? is gaining ground over here. But for a long time I didn’t know any way of finding out. The databases and corpora I usually consult primarily deal with published texts, and Sorry? is, of course, something that’s said far more than it’s written. Moreover, none of my sources pay any heed to punctuation, so any search would bring thousands of leaden I’m sorrys and sorry states for a single piece of gold.
Then Mark Liberman of the University of Pennsylvania advised me that the Corpus of Contemporary American English over at Brigham Young University indeed allows you to include punctuation in searches. Bingo. A search of broadcast transcripts yielded about 150 hits, most recently this from a journalistically hard-hitting ABC Primetime Live segment called DIRTY DINING: WAITER DROPS FOOD, TRIES TO SERVE IT:
GREG-1ACTOR2-# Here you go. And that’s it. (Voiceover) And before they can take that first bite… DINER-1MALE2-# Guys? One of your sandwiches, he just dropped it. ACTRESS-1FEMALE2# I’m sorry? DINER-1MALE2-# He just dropped one of your plates. The sandwich went on the floor, right here.
And this from a 2010 CNN interview:
KING: The mood there must be pretty good, huh? LAVANDERA: I’m sorry? KING: The mood must be pretty good?
The sharp-eyed will notice that in both those cases the speaker said “I’m sorry?” rather than simply “Sorry?” This is the case with a considerable majority of the COLA hits, one exception being this double-sorry from a segment on NPR’s Talk of the Nation. It starts off with the host, Neil Conan, interrupting a long statement by a caller, Eric:
CONAN: Eric – I’m sorry. Eric? ERIC: Sorry? Go ahead. CONAN: I was to ask you if you had any more. ERIC: Oh, no. I’m, you know, the only concern that I have is as far as, you know, I mean, everybody is concerned about their privacy.
Now that I examine the quote, it seems that both Eric and Conan are saying “sorry” to actually apologize. In any case, my hypothesis is that Americans, as is their wont, have subtly altered the British Sorry? into the more literal I’m sorry? Agreement, disagreement, explanation and any other amplification welcome.