Both ways are used, in my experience, here in the western U.S. Thing is, I'm not sure one can easily predict the pronunciation of one word based solely (or in large part) on how a similarily spelled word is vocalized.
By the way, by "both ways" I meant AB Editor's example of the one he doesn't use, i.e. 'herrisment'... When I hear 'herrisment', I don't think it's an affectation, (harRASSment seemingly being favored) rather more likely a regional difference... more often heard in the eastern areas of the U.S. as opposed to the south or west...