Ok, so this is just a hobby for me, and I don’t have a library of sources

. One example is the mmmm sound. M in Hebrew is represented by the glyph “mem” meaning “water” and loosely represents spirit (this is Kabbalah stuff). In Ogham M is represented by the glyph “muinn” meaning “strongest of efforts” and loosely represents harvest or play.
Mmmmm is a sound that a baby makes when it is hungry for nursing. Babies wanting to nurse can be connected (in my mind!) to the ideas of water(drink), spirit(life), play (with mum), food(harvest), effort to live.
Before anyone comes at me and says, “Ummm, you DO know that Hebrew and Gaelge are not connected in the least, right?!” I say, yes I am aware that these languages developed far and away from each other. However, I am thinking of sounds in a proto-language type of way. So wayyyy back, like 75,000 years ago when there was a bottleneck of human population (Toba Catastrophe Theory) and art (ochre body painting thought to be in use possibly for 300,000 years) and tools were already present and sounds were being given meaning. A single sound *could not* have a single meaning today because so much has tumbled forth from those ancient utterances, but there might be a kind of family of meanings, for *some* languages. Are there isolates? Yes.
Speaking of, have you ever looked at a family trees of languages? I love those! Pretty sure they are on Wikipedia.
I don’t think that was the kind of answer you’re looking for?, but that’s how my brain thinks about it, for what it’s worth!