There are many ways in which the word "concurrent" can appear in phonetics and phonology. In production, speech involves the concurrent control of many articulators; in recognition, we may (or may not) recognize features of phones concurrently; autosegmental phonological theories are based on extended concurrent features; Khoisan languages look as if they have click phonemes concurring with "normal" phonemes.
Most of those statements are pretty woolly; trying to make them more precise leads to interesting (to me!) conceptual questions and possibilities for more robust definitions. This talk is an exploration of some currently rather vague ideas; my aim is to get feedback from you of which, if any, might be worth pursuing from the viewpoint of the phonological community.
I'll start with a brief discussion of "concurrent". This has an ordinary meaning; but in theoretical computer science, "concurrency" has developed a technical meaning which is significantly richer (and, of course, more precisely defined) than the ordinary meaning. I will explain, informally and briefly, what this meaning is, and I'll introduce one of the standard formalisms for representing concurrency (pictorial, rather than algebraic!).
I'll then show how such a formalism can quite nicely be used as a formal model for aspects of phonetics and phonology (extending, for example, the work of Bird and Ellision on synchronizing automata and one-level phonology). In particular, I'll demonstrate, I hope, that autosegmental approaches are natural in this formalism, and that some phonological rules can be naturally represented by a technique like underspecification.
I'll then speculate on whether the extensive theories of concurrency developed in CS can be employed to formalize relationships between different levels of phonetic and phonological abstraction; and whether one might use them to achieve a rapprochement between traditional phonemics and autosegmental approaches, in which the concept of "phoneme" might be derived.
If time permits, I will consider the question "what would it actually mean to say that !Xóõ has concurrent click phonemes?" (I promise not to chicken out of saying "!Xóõ".) I can't yet answer it, but I'll suggest some approaches, which might even lead to interesting perceptual experiments. (Cf. talk by Catherine Best at forthcoming ICPhS.)
Lastly, if there is time, I will speculate even more wildly on possible applications, such as multi-lingual speech recognition by assembling language-independent feature-recognizing nets using concurrent formalisms to define language-specific ways of extracting phones and then phonemes (inspired by Mirjam Wester's recent talk).