Here, Jim: I am this forum's official PEDANT!

Actually, some use one term, some another ~~ interchangeable ~~ baby's dummy, baby's pacifier, baby's comforter ~~ I have heard them all used. Context, as in most such cases, will make clear.

I reiterate my point, that if OP meant that mobiles = any of above, his point may be valid: otherwise the thread title is mis-spelt.

~M~

Synonyms, Thesaurus & Antonyms of 'baby's dummy'         Princeton's WordNet

1. (noun) comforter, pacifier, baby's dummy, teething ring
device used for an infant to suck or bite on
Synonyms: teething ring, conciliator, allayer, sympathiser, quilt, make-peace, reliever, pacifier, comfort, sympathizer, peacemaker, baby's dummy, reconciler, comforter, puff