When we were in synagogue for Rosh Hashanah (a couple weeks back), I was with Tovina in the way back corner of the sanctuary while she was playing with some toys when the shofar (ram's horn) was blown. (Blowing the shofar is one of the big events at Rosh Hashana and Yom Kippur.) Tovina has heard a shofar before, but since she was only 1 year old at the time, apparently she didn't remember.
Her head whipped around as she tried to figure out what that noise was and where it might be coming from. She excitedly pulled me to the center aisle so she could have a good view and then pointed and stared very intently. Her eyes got big and she had a big smile. The shofar was blown a few times, when it was time, I'd pick her up so she could see better. Such an enraptured expression! Since the shofar is suppose to be a joyous sound we considered this a BIG SUCCESS!
Tovina also started imitating a shofar noise and pretended to keep blowing it as she walked around for a bit. It seemed most appropriate.