You could have a look at the sound examples on the Wikipedia article on aspiration. Specifically the Chinese and Indian example are very clear to show the difference, and there’s a section on (ancient) Greek as well
Is it possible you’re detecting the assimilation of some consonants (especially the velar ones) to the place of articulation of the following vowel?
Wikipedia seems to indicate that χ is still a fricative even when fronted, but it’s possible that Wikipedia is either outdated or referring to a different dialect of Greek than you are
Wikipedia might have a suggested explanation for Southern dialects
Learning English and German in school, I never realised there was a difference in pronunciation of “p” in “pin” (p in initial position in a word) and “spin” (p in any other position in a word). But “pin” is more pronounced like “phin” (by which I don’t mean an “f”-sound, but an aspirated p, with an extra puff of air after the p, so more or less like “p’hin”) by native English speakers and native German speakers.
In Dutch, “p” is always pronounced as in “spin” (unaspirated p), whatever the position, and I only started noticing the difference beween “pin” and “spin” when it was pointed out to me long after I finished school.
And English doesn’t only have this aspiration with an intial “p” sound, it’s also with an initial “k”-sound and an initial “t”-sound.
Even an initial “w” can be aspirated in English, although the aspiration then precedes the “w”, pronouncing “white” as “hwhite”.
I suppose it does depend a bit on whether the native English speaker puts emphasis on those initial consonants.
Here is an example of someone exaggerating it a bit.
It is not the possession of truth, but the success which attends the seeking after it, that enriches the seeker and brings happiness to him. — Max Planck
I assume this youtuber is Dutch because I cannot detect any foreign accent when he pronounces Dutch phrases. But I also can’t hear a Dutch accent when he speaks English (that is 90% of the time), or German. That is notable, because even though many Dutch people can speak English and German, they will have a clear Dutch accent.
Either way, I think this video explains quite well how Dutch and German grew to become distinct languages.
Not sure if this is the right place for this. Also not sure what the point of my observation is but maybe someone has an opinion towards this or thinks it’s interesting.
So “Go” has a different name in Korean (Baduk), Japanese (Igo) and Chinese (Weiqi). But I recently realized that they all seem to use the same Hanja in relation to the game. The “Qi” in the Chinese “Weiqi”, the “Ki” in the Korean “World Kiseon Championship” and the Ki in the Japanese Kifu, are all referring to either A. the word “game” in general or B. the “game of go” specifically. Actually not sure which one it is but for Korean at least I think “Ki” (Gi, 기) usually refers to Baduk specifically?
Interestingly enough the Hanja for the “Wei” in Weiqi is also still used in Korea today. For example in the pretty common words Juwi (surroundings/주위), Beomwi (scope/범위) and Powi (siege/포위). In Chinese the Hanja is pronounced like “way” while in Korean its pronounced like “we”.
So theoretically instead of saying Baduk (바둑) in Korean you could also use the Hanjas for “surrounding game” and say Wigi (위기). But practically the word Wigi (위기) means “crisis” in modern Korean and no one would understand you.