Always on the lookout for textural descriptors of speech. (See earlier blogpost on research showing that the brain seems to process textural "metaphors" quite literally.) It has been discovered that ravens lower their voices in response to calls from enemies or strangers, according to the researchers, to affect the perception of a larger body size. They note other studies showing that "smaller" mammals, including smaller humans, tend to "roughen" their voices to accomplish something of the same function. (I'm following up on that rabbit trail as well, of course!) In EHIEP, for example, we use the term "rough" with students to refer to most lax (short) vowels, in part to help distance them from their four tense "neighbors." Tense vowels, in turn, are termed, smooth, and diphthongs as "double (smooth)." One of the basic principles of voice training or simple change in voice quality setting is the requirement that learners adopt a new felt sense of their voice as "homework" temporarily. The basic idea is to create a separate, almost parallel voice style that can be worked on somewhat independently without at least initially interfering with normal day to day conversation. That may be done by slightly deepening, raising, smoothing or "roughening" the presenting vocal style, just enough so that the learner can switch into it consistently in practice. Got a few "foul vowels" among your students? Just rough them up or smooth them out . . .