I noticed in movie 4 that the Longneck herd almost sounded like cows when they were first arriving.  In movie 5, that T-rex roar almost sounded like an elephant.   

I'm wondering, which of the main characters CAN make a noise?

So far, I think I can guess the following:

Chomper - roaring (though perhaps not the best at his current age)

Cera - that weird screech of hers (though she has only used it in the first few films)

Petrie - possibly he can make the same noise as that Pteranodon did in the 2nd movie when she chased off Ozzy and Strut.

Ducky - Unknown

Spike - Unknown

Littlefoot - Might be able toi sound like a cow.   Also, i thought his mother made some weird sound when fighting Sharptooth.

Ruby - unknown

Sierra - think he had one too (or at least the wiki said he did.)

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