I used to answer almost everything I wasn’t expecting with “what was that?” and then a second later would answer normally — it was like my brain took a second longer for to process what I heard than it did for my brain it assume I didn’t hear it. Oddly enough, though, I have zero problems with word retrieval. I know exactly what I’m going to say, and am usually two thoughts ahead. Sometimes I just can’t get the word to come out, though.