Late last week, Jasper startled us by letting loose a string of syllables. All the same one, mind you, but a hearing your son suddenly chanting "blah blah blah blah"* is pretty damn funny. Since then, he's alternated "blah" with "yah" "wah" "mah" and other one syllable words ending in "ah." Most humorously, he has also started mouthing the words, as seen below. I have no explanation.
* I refuse to acknowledge "blah" as my son's first word.