Whoa, "male from United States" says "sism" here: https://forvo.com/word/schism/#en . I honestly had no idea there was more than one pronunciation of this word.
― Locked in silent monologue, in silent scream (Sund4r), Thursday, 15 November 2018 11:56 (five years ago) link
'Female from United States' says both. Could it be a regional thing?
― pomenitul, Thursday, 15 November 2018 12:03 (five years ago) link
My informants are from the working-class northeast but I was guessing it may be generational.
― mick signals, Thursday, 15 November 2018 14:06 (five years ago) link