What is this い sound change?


I often hear 全員 pronounced as ”ぜいいん”. I also read online that 雰囲気 can
sometimes be heard as "ふいんき” although I have personally never heard that. I
have a few questions about this phenomenon:

  1. Is there a name for this?
  2. Are there any more common examples of this that I should look out for in speech?
  3. Does it carry some nuance(e.g. street talk, old man, etc), possibly similar to what ないー＞ねえ carries?
  4. And finally, where am I most likely going to hear this(if at all)? Or in other words - is this a regional thing?




全員 surely sounds like ぜいいん [ z ẽ ĩ ] but it's still different from pure ぜいいん [
z e: ĩ ]. It's a normal phenomenon called assimilation and a natural
consequence when you pronounce it without being particularly enunciated as [ z
e ɴ i ɴ ]. [ e ɴ ] turning into [ ẽ ] is parallel to [ t j ] as in "hit you"
turning into [ tʃ ]

It's not considered accent or slur, and not unique to a certain region.




全員 surely sounds like ぜいいん [ z ẽ ĩ ] but it's still different from pure ぜいいん [
z e: ĩ ]. It's a normal phenomenon called assimilation and a natural
consequence when you pronounce it without being particularly enunciated as [ z
e ɴ i ɴ ]. [ e ɴ ] turning into [ ẽ ] is parallel to [ t j ] as in "hit you"
turning into [ tʃ ]

It's not considered accent or slur, and not unique to a certain region.

