The capacity to produce novel utterances is an attribute of every natural language.

As liberty of thought is absolute, so is liberty of speech, which is "inseparable" from the liberty of thought. Liberty of speech, moreover, is essential not only for its own sake but for the sake of truth, which requires absolute liberty for the utterance of unpopular and even demonstrably false opinions.

E'en then – alas! to Trojan ears in vain – / Cassandra sang, and told in utterance plain / the coming doom.

The utterance is potentially misleading.

Then again / a third tall shaft I grasp, with sinewy strain / and firm knees pressed against the sandy ground; / when O! shall tongue make utterance or refrain? / forth from below a dismal, groaning sound / heaves, and a piteous voice is wafted from the mound:

This utterance is not a sentence.

Then Priam, though hemmed with death on every side, / spared not his utterance, nor his wrath controlled.

Tom has naturally a very agreeable voice and utterance.

Mary gave utterance to her outrage and turned away from Tom, offended.

Technically, a burp could be considered an utterance.