Since attire has no effect on the quality of the shiur
au contraire! (adarabah)
attire certainly has an effect on the quality of the shiur as it goes out, as Chazal say in so many places that the chitzonius affects the pnimius.
and kol shkain attire has a profound effect on the quality of the shiur as it goes in. it is pashut that the effect of a statement is highly dependent on how one views the source from which it emanates, even if the exact same words are said by two very differently perceived speakers.