Sound it out

Nicholas' aunt is named Shelby. You need to know that for this story.
Last night, when he was lying in bed and trying to avoid going to sleep, he began sounding out the first letter of everyone's name. First:
Mm-Mm-Mm. Mommy.
Next: Da-Da-Da. Daddy.
I was impressed and said so. Then,
Na-Na-Na. Nicholas.
And finally,
Ja-Ja-Ja. Shelby.
It was one of those moments where you have to squelch your laughter.