I have listened very closely for ommited consonant sounds from the pronunciation habits of different speakers, and aside from the differences in the "dialects" of English's throughout the world, it seems obvious that a familiarity with the most common context of words will, once acheived, fill in the missing sounds, and allow one to know the intended meaning/word. Very few people pronounce all of the scripted sounds.

This is similar to the how one's brain and eyes communicate when watching an animated cartoon - essentially "filling in" or "smoothing over" the "steps"... making it a "ramp".