In connected speech there occur various phonological reductions and the distribution of those processes varies as the spoken style varies in the degree of formality. I am looking for such learning material as teaches phonological reductions in accordance to different styles of speech formality. Does anyone have any recommendation on this?
Many linguistic textbooks present facts of phonological reduction in connected speech but do not deliver instruction on their usage. Those textbooks do not specify in which type of communication circumstances should some type of reduction be used or avoided. Hence I am looking for something really pedagogical, not purely theoretical.