The anachronism of the "ph" or gender models Were Stephen as "Steven" and Stephan as "Stefan"
However modern matrix gives esoteric orientations to the weilders of them both as ambiguously pronounceable as They can be contrasted to the grammatic "v" spelling.
It depends where the weilder is when an announcer reads their formal.
Grammatically "ph" is unvoiced "F" sound.