Dear Bob,

> There appears to be no reference, as far as I have found yet, in the
> references I'm using so far, as to how <lingual+nasal "n"> sounds and is
> pronounced? It is the "n" with the dot underneath it!

This sound does not exist in English and probably only purists try to
pronounce it properly, but it is worth making the effort. The underdotted n
forms, with the underdotted t, th, d and dh, a class of Indic sounds known
as retroflexes, or cerebrals in older works. Also found in Sanskrit and not
Pali is the underdotted s, which is also a retroflex "sh" sound.
Actually, they are not too difficult to manage with a bit of practice. In
standard English, the sounds t, d and n are articulated about midway between
the true dentals found in most languages including Pali and Sanskrit but not
far enough back to be retroflexes -- though they apparently sound closer to
retroflexes than dentals to most Indian ears.
If you pay careful attention when you say these sounds in English, you
should find that the tip of your tongue does not touch the backs of your
upper front teeth but the hard ridge just behind. To make a true dental
sound for t/d/n for Pali etc, the tip of your tongue needs to stretch
forward a bit more and touch your teeth. For the retroflexes, you need to
draw/curl back your tongue just a bit more to the concave roof of your mouth
past the hard region just behind your teeth. To my ears, the difference
between dentals and retroflexes is that the former have a clear crisp sound
while the retroflexes seem somewhat muddy.

Does this help ?

Best wishes,
Stephen Hodge

PS: I suppose you will next want to know how to pronounce the aspirated
sounds :)