I found this BBC article about life in Antarctica very interesting, particularly the part about the crew of 26 developing a new "accent" during the winter. Part of what they were studying was what happens to language in a remote, isolated location.
All they knew was that they were taking part in an unusual experiment, which involved tracking their own voices over time. This was done by making 10-minute recordings every few weeks. They would sit in front of a microphone and repeat the same 29 words as they appeared on a computer screen. Food. Coffee. Hid. Airflow. Most were words they used regularly during their day and contained vowel sounds known to differ in English accents.
When the recordings finally got back to a team of phonetics researchers at the Ludwig-Maximilians-University of Munich in Germany for analysis, they discovered that the pronunciation of some of the words had changed ever so slightly. What they were seeing was the beginning of a new accent emerging.
Where the DrsC have noticed this in in New Zealand, one of the most geographically isolated nations on earth. NZ speaks English as its primary language. In visiting there we found the speech of women and young adults difficult to understand, adult men were relatively easier to decode.
For example, driving a small rental motorhome at the south end of the South Island, we camped at a private camp run by the property's owners. Out for a stroll, we met the owner and her small dog.
We asked the dog's name and were told it was Gee See. Unclear about what we'd heard we asked for a repeat, and again heard Gee See. Feigning deafness we asked for a spelling, she spelled J.E.S.S.E.E. and reiterated Gee See.
We would call that name Jess ee, rhyming with messy. It was clear she pronounced both e and ee as what we call long e. It is possible she'd also pronounce messy as Mee See.
Interestingly, while we had difficulty understanding women and youths in NZ, they had no difficulty understanding us. They watch a lot of US made films and TV shows and are familiar with our US accent, which however they do not copy.
We never got an explanation of why NZ men were more understandable. Maybe it is because more of them have been off-island for extended periods.
