Ellie's thinking noise

For months Ellie has made this same noise when she's trying to come up with the answer to the question you ask her. It took us awhile to figure out what she was doing (we thought she was asking us to repeat the question), but once did it made a lot of sense. I have no idea how much longer she'll do it, so I had to get it on video. The noise (a 'huh?) typically goes on until you either ask her a follow up question or you change the subject completely. Every once in awhile she can go from this noise to the correct answer on her own. It's hilarious, we love it, and it's a fabulous Ellie quirk.