Makes for a pretty good introduction as to me, Chuck!
It might be added that "hearing" a certain mode can be supported by figuring the sound of the related chords, say the significant alternation of minor tonic (I) and major subdominant (IV) for recognizing the Dorian mode, and just the other way round of major tonic (I) and minor dominant (V) for the Mixolydian mode (for instance for D Dorian D minor and G major, and for G Mixolydian G major and D minor).
The major and minor chords as referred to are basically triads made of a
1) major: a major third (4 semitones) and then a minor third (3 semitones)
2) minor: a minor third (3 semitones) and then a major third (4 semitones)
With their sounds in mind the manoeuver as described above can be performed.
Example for "hearing" Dorian: "Parsley, sage, rosemary and thyme" (from "Scarborough Fair")
Example for "hearing" Mixolydian: bar 5-6 (resp. 9-10, repeats included) of "my" Apley House"
(the latter initially being recorded just for that pupose)
Hope that helps...
(edited to add the examples)
Edited by blue eyed sailor, 21 February 2014 - 10:48 AM.