I have read historically the letter ayin was pronounced by some Dutch, Portuguese, and Italian Jews as a velar nasal consonant (ng as in sing). Reference to this can be found here, here, and here. I have also read in other places (that I can't find at this moment) that ayin as a nasal consonant was also used in Poland and other Yiddish speaking areas. This can be seen in the transformation over time of Ya'akov into Yankiv or Yankel.
An example showing this pronunciation in the context of a novel can be found in Children of the Ghetto, chapter 20 when a dying boy is told to say "Shemang" (שׁמע). The speaker in the story is a nineteenth century Jew of Polish origins, living in London.
The usually informative article "Phonology of Ashkenazic" by Dovid Katz says nothing about the nasal pronunciation, just a few paragraphs on page 69 explaining that the ayin and aleph went silent and a quote from Yekusiel of Prague complaining about that in 1395.
The author of this article states (on page 194) that the nasal ayin could be heard in many cities in Europe until the Holocaust, but he believes that the only place where this historic pronunciation can be heard today is in Amsterdam (page 198).
My question is: Is this pronunciation used anywhere else? If it was really as common 100 years ago as these authors claim, I would expect there to be communities in America that preserve it. I am sure that there would be a tendency for "modernists" to make it silent like in standard Israeli Hebrew, but many orthodox communities preserve older pronunciations out of a desire not to change their mesorah. Have any of you heard "shemang" or similar pronunciations used in prayer or in Torah reading? If so, in what community was that in?