A Lateral Kick to the Shins: Part 5

John Ohala is a professor at Berkeley (now emeritus) who has done an enormous amount of work on the phonetic mechanisms of sound change. He has concluded that the primary source of sound change is incorrect parsing of speech sounds by listeners, either by dissociating signals that are meant (by speakers) to represent the same sound or by associating signals that are meant to be distinct sounds. In the Akkadian change we are discussing here, it is clear that the origin of the change must be the second of Ohala’s processes: listeners hearing [št] and [ɬt] and assuming they are the same, then adjusting their own speech to pronounce the two sequences identically as [ɬt]. Although the two fricatives are distinct articulatorily, there is considerable evidence that they are similar acoustically. I will present some such evidence (from languages which have both as phonemes) in a later post; right now the important thing to consider is just that they are indeed similar, and this similarity led to a perceptual confusion.

Here I would just like to detail the process I am proposing for this sound change, since I'm not sure it was very clear in my original paper. Basically, I'm arguing that there was a phonological rule in Akkadian starting at an early stage (it's impossible to tell exactly how early, but certainly by the Old Babylonian period) which devoiced /l/ before /t/ and /s/. This rule, although it is necessary for explaining the sound change, is separate from it, and may well have operated before other voiceless obstruents as well; there's just no way to tell from the textual evidence since no sound changes occurred in those environments. Later, during the Middle Babylonian period, the perceptual confusion I mentioned above began to develop, with texts showing sporadic cases of for <š> before . As this confusion continued through generations, the pronunciation of /š/ moved more and more in the direction of [ɬ], until finally the two allophones (of different phonemes, remember) became identical in pronunciation and the allophone of /š/ in this environment actually became [ɬ], which was also the allophone of /l/. This is thus a total merger in a highly specific context. Later, by the time of the Neo-Babylonian period, the change had spread analogically to environments before the other coronal obstruents /d/, /ṭ/, /s/, and /z/; the resulting phone was presumably pronounced as a voiced [l] before the voiced segments (its realization before the emphatic is unclear due to our lack of knowledge of its pronunciation).

This is a complicated, multi-step change, but I think it is the only way to adequately explain this unusual shift. In my next post I will present some phonetic evidence to bolster my contentions here.