A good example of how to say it in this dialect is to practise saying just the "ng" in "sing". This sound only happens with Gs in the middle or end of words, though (or if you're slurring or speaking quickly, hah). Gs at the beginning of words will have the more familiar sound, as in "good", etc.
True, nowadays, from what I hear, it's 'hipper' or whatnot to steer away from saying it too strongly like this. A lot of grammer books still teach it as a standard pronunciation, though, since it's still commonly heard, otherwise, especially with certain dialects and age groups.
Yes nasal pronunciation sounds like ng but the audio isn't a nasal it has no g sound at all. I have listed to it a dozen times, and I mean I am aware of the nasal g, heck I posted a link to some audio to help people with that in a previous lesson.
But this seems like not a very good audio to me. Seems like just mini. Maybe should firm up the g sound for a teaching audio.
I had my wife listen just to see if I was crazy and asked what she heard and she said it sounded like mimi. But she isn't Japanese she's Korean. (Also is it wrong to be studying Japanese when my in-laws are korean? Lol)
I have no clue what the real meaning is but I thought of a fun way to remember the kanjis just now:
You eat with your right hand (mouth, get it?) You work with your left hand(construction, lol)
Maybe the real meaning taught in Japan has some old story about how amaterasu built the earth with her left and ate divine fruit with the right or something XD