My mother picked up on this on her first day in Japan. Particularly on the boat between Asakusa and the Intercontinental Tokyo Bay (just past Hama Rikyu).

Thanks to MrLapLap, we got a distilled translation of what the guide was saying (and she was excellent; friendly, great diction, very professional). My mother felt she was ending every other sentence with ‘arimas. So richarddd, you aren’t alone.