Very smart #linguistics folx, your attention please 🙏

Given the #IPA həˈləʊ, is there or is there not only "one way" of that being pronounced?
If so, by extension, correct in assuming the phoneme ə can again only be "pronounced" one way?

Why then does the ə on https://commons.wikimedia.org/wiki/General_phonetics#Vowels not sound like the ə in the word hello (represented as həˈləʊ)???

General phonetics - Wikimedia Commons

@theresnotime sounds like for the purposes of your project it might make sense to first programmatically convert the broad transcription (with the slashes) to a narrow one (with square brackets), which would mean implementing various contextual phonological rules, e.g. /p/ becomes [pʰ] at the onset of a stressed syllable. then again, as others have remarked there’s a limit to how useful a narrow transcription can be.