Home of Rhett & Link fans - the Mythical Beasts!
If you went for an entire day without using gestures, sign language, or any language for that matter, and only communicated with others making noises, do you think that others could tell what you were talking about just by the tone of your voice? I think that eventually you would all just be screaming and making noises at each other.
Tone and inflection are mostly used to communicate mood and intention. For example, it's widely recognized that raising your inflection at the end of a statement means it's actually a question, and lowering your tone below its normal range suggests discontent or aggression.
Sure, with just vocal tones you can understand someone's emotional state and thus their intention in making noises at you in the first place. If you want to hold a complex conversation, though, you're going to need more than varying tones of grunting.
SAYS YOU! obviously looking at this only from the femell perspective . . .
Ahem. I believe the question specified going "an entire day without using gestures, sign language, or any language for that matter." I think Tim Allen would be a little lost.