Bilabial

I wonder if the bilabial sound of papa and moma were selected so babies could alert their parents?

bilabial (by-LAY-bee-uhl) adjective

Using both lips.

noun

A bilabial sound or consonant, for example p, b, m, where both lips
touch each other, and w in which lips are rounded.

[Latin bi- (two) + labial, from labium (lip), ultimately from Indo-European
root leb- (lip, to lick) that's also the source of lip, labrose (having
thick or large lips), and labret (an ornament worn in a pierced lip).]

Today's word in Visual Thesaurus: http://visualthesaurus.com/?w1=bilabial

-Anu Garg (gargATwordsmith.org)

"Bilabial sounds like mamma, papa and baba are probably the easiest for
the infant mouth to master."
Jack Rosenthal; From Arf to Zap; The New York Times; Jun 30, 1985.