He also seems to make a "mi mi mi" sound when he wants his milk. The last few days we've been hearing an emergence of /d/ - not quite dadadada, but I think it will be there soon.
Lastly - Nate and I decided last night that it will NEVER get old to watch our deaf son dance to music every time he hears it. It's always unprompted too. He dances because he HEARS the music! Amazing... I never thought I'd see that day. It makes me cry just thinking about it. Enjoy this fun little video too! (it's not captioned, because there's no talking, just music and "dancing!")