Voice (is) audible

[Sped Tiger]

Could you say how you call this type of phrase? It's usually used in books, as I've noticed. And also, why isn't there any auxiliary verb? Would it be wrong if I put one in such a phrase?
Examples (the auxiliary verbs not used are in brackets):
1. "I'm afraid," said Polina, voice [was] barely audible;
2. And he said, "I have seen... a ghost!" eyes (were) wide open;
3. George began eating, his mouth (was) full of saliva.

 

[Barque]

"I'm afraid," said Polina, voice barely audible.

This is fine. If you add "was" it'd be ungrammatical. You'd have to change the structure.

And he said, "I have seen... a ghost!", eyes wide open.

This doesn't work for me because "eyes wide open" doesn't accompany "And he said".
I'd prefer: And he said, with eyes open wide,"I've seen a ghost!"

George began eating, his mouth full of saliva.

This is grammatical but "full of saliva" sounds a little odd in this sentence. If you add "was", it'd be ungrammatical.
I'd say: George was salivating/drooling as he began eating/started to eat.

Could you tell me say how what you call this sort type of phrase?

I don't know. Maybe someone else will answer that.