The workings of phonology and its interfaces in a modular perspective
Tobias Scheer
Université de Nice
Since its inception in the 1950s, the Chomskian enterprise is modular in kind: distinct
computational systems using distinct and mutually unintelligible vocabularies concur to
produce and perceive language. This perspective represents the application to language of themore general take on how the human cognitive system works (the so-called cognitive
revolution of the 1950s, condensed in Fodor 1983). It contrasts with the connectionist
approach that has emerged in the late 1980s which promotes indistinction: there are no
distinct computational systems or distinct vocabulary sets.
The modularity of mind has a number of consequences when applied to language. The
grammatical architecture resulting from this perspective is the so-called inverted T that is inplace since Aspects (Chomsky 1965) where one concatenative system (morpho-syntax) and
two interpretative modules (semantics and phonology) are distinguished (in production). The
mutual unintelligibility of those systems is due to the distinct vocabulary that they process(domain specificity): things like person, number, animacy in morpho-syntax, against items
such as labial, plosiveness etc. in phonology. As a consequence modules are incommunicado
as such and need a translation device in order to talk to each other: this is what interface
theory is about.
In the history of generative linguistics the interface between morpho-syntax and phonology
was always more developed than the one that relates phonology to phonetics. Regarding theformer nobody doubts that the translational process is achieved through a lexical access (anoperation called spell-out): a morpho-syntactic structure that describes, say, past tense of aweak verb in English is realized as -ed because there is a lexical entry stored in long-term
memory that specifies this equivalence (past tense [weak verbs] ↔ -ed). Since lexical
properties by definition do not follow from anything (at least synchronically speaking), therelationship between the input and the output of this spell-out is arbitrary: there is no reason
why, say, -ed, rather than -s, -et or -a realizes past tense in English.
The arbitrariness of the categories that are related by the translational process is thus anecessary property of this process: it follows from the fact that vocabulary items on either sidecannot be parsed or understood on the other side. By definition, the natural locus ofarbitrariness is the lexicon: therefore spell-out goes through a lexical access.
If grammar is modular in kind then all intermodular relationships must instantiate the samearchitectural properties. That is, what is true and undisputed for the upper interface ofphonology (with morpho-syntax) must also characterize its lower interface (with phonetics):
there must be a spell-out operation whose input (phonological categories) entertain anarbitrary relationship with its output (phonetic categories). That is, there is no automaticity ornecessity for, say, [+labial] to be pronounced as a labial articulation [p,b,v,u,o etc.]. It could
as well be pronounced as [χ] or [t]. Arbitrariness in the phonology-phonetics interface iscounter-intuitive because unlike at the upper interface our experience is that the relationship is
99% faithful: what is labial in phonology is also labial in phonetics. There are distortions,though, which show that translation may be non-faithful, such as the variable pronunciation of
the phonological sonorant /r/, which appears as [ʃ,ʒ] in Polish, [h] in Brazilian Protuguese or[ʁ,χ] in French and German.
Building among other things on so-called crazy rules (phonological processes that make nosense phonetically speaking, such as l → ʁ / V__V in Sardinian), the goal of the talk is toconvince the audience that the lower interface of phonology is just as arbitrary as its upperinterface. Two reasons will be shown to account for the fact that 99% of lower translational
relations are faithful (while faithfulness is not even a relevant category at the upper interface):the ontology of morpho-syntax (grammar-internal, no real-world categories involved) as
opposed to phonetics (concerned with real-world categories) and the diachronic origin of nonfaithful relationships at the lower interface (rules and phonology-phonetic mappings are notborn crazy, they become crazy through aging).
Another issue that the talk develops is the decomposition of what is commonly consideredas phonology into two distinct computational systems: two phonologies. As will be shown by
a number of empirical diagnostics, the area below the skeleton (segmental, melodic) has
workings and uses a vocabulary that are completely distinct from the area at and above theskeleton (prosody). Hence a palatalisation belongs to the melodic module, while stressassignment, syllable structure or infixation are negotiated by the prosodic module. The
communication with morpho-syntax also evidences the split at the skeleton: the melodic
world is completely incommunicado (in both directions), while the prosodic world doesinteract (i.e. is conditioned by and does condition morpho-syntax).