Pronouncing 'Envelope'

This is just a bit of curiosity on my part spurred from being home from college. I noticed that my mother and I pronounce 'envelope' entirely differently. I pronounce it 'AHN-ve-lope' as in 'ensemble' while she pronounces it 'en-ve-lope,' which is believe is 'standard.' I think she pronounces the verb the same as the noun, but, when I say the verb, I say 'to en-VEH-lup.' Erk.

Regional note: she grew up in the American Midwest, while I grew up all over the US, with my language learning years spent in Chicago and, then, New York, so I was thinking it might just be a regional thing. Perhaps? We have significantly different accents.

I'm just curious about the regional ways to say 'envelope,' as well as which version is truly standard. And those who pronounce the 'en' as in 'ensemble,' how do you pronounce the verb? <i>Am I abnormal</i>? /angst