Date: Mon, 10 Apr 1995 10:53:13 -0400 From: ALICE FABER Subject: Peripherality Terry Irons asks, with regard to the Southern Shift: >> Could you clarify for me what peripheral/nonperipheral mean in acoustic >> and articulatory terms? As a matter of fact, no. I don't mean to be flip. It's just that the peripheral/non-peripheral distinction, like the tense/lax distinction, has no empirical basis. They're both ways of labeling two sets of vowels that we all *know* are different. Labov, in his new book, has lots of diagrams showing peripheral vs. non-peripheral vowels in terms of the boundaries of the vowel quadrilateral. Ocke Bohn (of the University of Kiel) recently gave a talk here at Haskins in which he appealed to the same peripheral/non-peripheral distinction for very different purposes, to explain Pat Kuhl's magnet/prototype effect (in a nutshell, it's harder to hear small differences between vowel tokens that are near some posited prototype than it is to hear differences of comparable physical magnitude that are not near the prototype). Giving theoretical support to the notion of peripherality would depend on providing a theoretical interpretation of the vowel quadrilateral. In intro books, we talk about it terms of the position of the highest portion of the tongue. However, physiological studies (x-ray, etc), especially those by Sidney Wood, have shown that this is not an appropriate way to describe vowel articulation. In acoustic terms, there's a reasonably good fit between the vowel quadrilateral and F1/F2 plots of acoustic measures (especially if you use a logarithmic scale and plot F2-F1 rather than simply F2). But it's really unlikely (in my opinion, others may disagree) that speakers produce and understand speech in terms of formant frequencies (we understand people with very different sized vocal tracts...). As I said, the peripheral/non-peripheral distinction is (nearly) isomorphic to the phonological distinction between tense and lax vowels. You'll read in various places that tense vowels are produced with greater articulatory force than their lax counterparts. The problem with this is that the one attempt to test this by using electromyography to measure electrical activity in tongue muscles found no consistent relationship between vowel type and activity; for some speakers, /iy/ had activity of longer duration than that for /ih/, as if there was activity for the nucleus and activity for the glide separately. (This study was by Freddie Bell-Berti and Larry Raphael). A problem with the tense/lax opposition is its replicability. Most people who appeal to it agree that the nuclei of beat, bait, and boot are tense, and those of bit, bet, and put are lax. However, there is much less agreement about the rest of the vowels: bat, but, pot, bought, boat. They're clearly partitioned in English between those that can be the nuclei of stressed C(C)V monosyllables (so long as you ignore duh and the Knights who say "nih"). Calling the raising of /ae/ in MAN "tensing" implies that it's lax, but it's still peripheral, no? Anyway, this has all been a long way around to justify my claim that there's no real theoretical motivation for peripheral/non-peripheral. That doesn't mean it's not a real partitioning of the vowels. It just means that we haven't figured it out yet. >> I am unaware of any principles of sound change. All I am familiar >> with are hypotheses within the context of certain paradigms and then >> certain facts. Perhaps you disagree with Labov as to what constitutes a principle... Alice Faber Faber[AT SYMBOL GOES HERE]