I've discussed Balaam's talking donkey before, but I'd like to add a few things:
1. Some unbelievers will say defending the historicity of this incident betrays the absurd lengths to which Christian inerrantists will go. How can anyone seriously defend anything that palpably ridiculous?
But that misses the point. It's like giving thumbs down to a Woody Allen comedy because it's too comedic.
The Balaam incident is intentionally satirical. God parodies the heathen seer. Yet ridiculous things happen in real life, and there's no a prior reason why God cannot, would not, or should not perform a satirical miracle.
2. By the same token, if we think this incident actually happened, then it's proper to explore different models. That's taking the account seriously. Even a miracle is realistic.
3. The basic objection to animal speech goes something like this: a donkey lacks the vocal chords, as well as language centers in the brain, to utter sentences. It lacks the brain structures to send commands to the tongue and vocal chords. It cannot coordinate the tongue, teeth, lips, and vocal chords to enunciate words. Even apes lack the necessary equipment, which is why primate researchers try to teach apes sign language.
4. Christians who defend the Balaam account often agree with unbelievers about what's required, but they say God miraculously changed the donkey to make that possible.
Now God is certainly able to do that. But as I read it, that's not what the text says or implies. I don't think it's necessary to say that God temporarily gave the donkey a human IQ, or gave the donkey instant fluency in the Moabite language.
The question is whether the donkey produced the sentences. I don't think so. Rather, It's preferable to think God directly produced the sentences. All that's needed is for Balaam to hear the words emanating from the donkey.
5. Part of the issue is how we visualize the account. In the past, when movies depicted talking animals, the effect looked like bad lip-synching. And that's what it looked like because that's what it was. Photograph what an animal naturally does with its mouth, then have an actor dub the dialogue. But the mismatch is evident.
With advances in CGI, it's now possible to depict talking animals on film (e.g. Aslan) where the animal appears to be forming words like a human would. But is that the right way to visualize the Balaam incident?
6. Consider the notion of disembodied voices. (I don't mean ghosts.)
In the modern era, we are saturated with disembodied voices. Movies, television, telephones, audio-recordings, &c. The voice, words, sentences, have been electronically detached from the physiology of speech. The technology reproduces speech.
Suppose you're watching actors in a movie theater. Because their speech is precisely synchronized with how they move their lips, and because we're so conditioned to viewing movies, it seems like we are hearing and seeing them speak. Like we're in the very same room with the actor, hearing words from his mouth. But that's an illusion.
We aren't hearing words issue from their mouths. Rather, audience members hear words issue from loudspeakers in the movie theater. By the same token, one might view Balaam's donkey as a kind of loudspeaker.
7. On a related note is the question of how God speaks to people. In Scripture, there are different modes:
i) God may speak to people in dreams. That's telepathic, simulated speech.
In fact, Maimonides thought the incident regarding Balaam's donkey was a visionary audition. His donkey didn't actually speak. That's something Balaam saw and heard in a vision. Cf. Guide to the Perplexed, 2.42.
And since Balaam was a seer, there's something to be said for that interpretation. It would also explain why Balaam takes the donkey's speech in stride. And I've discussed that interpretive option elsewhere:
But for now I wish to probe the traditional interpretation.
ii) In angelophanies, God may use a humanoid body to communicate.
iii) But sometimes, all the person hears is a disembodied voice. In that case, God is directly producing phonemes. Causing speech waveforms. The effect of phonation.
7. And that's one way to visualize the Balaam incident. It doesn't require the donkey to produce speech. Rather, speech is immediately produced by God, but localized in the donkey. Balaam heard words issuing from the donkey's mouth.