Grimm and Grimmer.

Thank you, PG and MCV. I've learned something. As for me retaining
what I've learned, or even being able to reproduce what you guys have
stated, well, Piotr and Miguel need to offer me a serious course in
phonology.

Piotr is telling us that PIE 'accent' essentially runs down to the
First Germanic Sound Shift (for Germanic, not Armenian). I've read
about creaky voice, but admit to not having any understanding of what
it sounds like.

Then there is the apparent absence of word-initial [b] and [p] in PIE,
vs the apple-word. I suspect this just might be a lexical thing,
rather like current English being able to do the words bwana and
Puerto Rico [pw], [bw], but not having these word-initial phonemes
natively.

Can a rule be assembled which explains why an earlier state of PIE
lost word-initial b/p?