This is a cross-section of the human articulatory apparatus. It consists of your mouth, nasal cavity and parts of your throat. All sounds in human languages are made by manipulating this apparatus in specific ways. They have all be studied in detail by linguistics and phoneticians. I learned studying linguistics that there is amazing symmetry in the sounds in human language. The symmetry is striking when we look at the place in the mouth where vowels are produced. Different vowels are produced by varying the position of the tongue in two principle ways – the height of the tongue and how far forward or back it goes. If we make a chart using those two axes and then we plot the principal vowels we find in human language on that chart, we get a V.
Not only do we get a V, it is almost always symmetrically filled. That is, if the language has i (the ee sound) it will have a u – the sound of oo in boot. If it has only five vowels, they can’t be just any five; they have to fill the V in a regular way. So Spanish has i, e, a, o and u, making a perfectly balanced V. If I am studying a previously unwritten and unstudied language and I find the sound ɛ (like the e in get), then I know that I have too look for ɔ (like the ough in sought) because if there is a vowel on the front of the V in the language, it will have its corresponding vowel in the back of the V at the same height and vice versa. There are similar symmetries with consonants. This makes the job of a Bible translator working on an unstudied language a lot easier because we know in advance that the language will not contain just any random selection of sounds.
There are explanations for this symmetry that don’t involve God and there is much more to vowels than I have presented here. Nevertheless, I find it a big leap of faith to conclude that human language with such symmetry was created solely by a long accumulation of random events.