It sent me on a trip and in the end to Hittite 𒆷𒄴𒉺𒀸 (laḫpaš, “ivory”) 3700 years ago

I love etymology honestly and how it is all connected. I am really curious about onomatopoeias.

For example is ‘hmmm’ used in many unrelated languages just because it has a soothing vibration? Why do we have same onomatopoeias in cultures that never met?

Is there a language that is closest to interpreting the brain signals if we consider onomatopoeias to be a part of the language?

Perhaps some primitive pre language consisting of grunts without words. Then the evolution comes into play and animal communication.