phase (n.)

A term used by some GRAMMARIANS to refer to the CONTRAST between PERFECT and non-perfect in the VERB PHRASE (of English, in the first instance). The term is intended to distinguish these forms from the PROGRESSIVE/ non-progressive contrast within ASPECT, and also from contrasts of TENSE and VOICE.

In ARTICULATORY PHONETICS, phase refers to a stage within the ARTICULATION of a SEGMENT. Typically, there is an onset phase, as an active articulator approaches the point of maximal CONSTRICTION of the VOCAL TRACT; a medial phase, where the articulation is reached and maintained; and an offset phase, during which the vocal organs move towards their next articulation, overlapping with the onset phase of that sound.

In ACOUSTIC PHONETICS, phase is part of the description of the waveforms that constitute speech. A ‘wave’ is a disturbance from equilibrium which propagates in time from one place to another. Speech waveforms can be decomposed into a number of waves of a regularly repeating kind (‘sine waves’), described with reference to their AMPLITUDE, FREQUENCY and time. When sine waves start at different degrees of displacement from the source, they are said to display differences in phase.

In the MINIMALIST PROGRAMME, a phase is a unit in a DERIVATION that operates as an independent piece of SYNTACTIC structure. The derivation of a sentence takes place phase by phase, and syntactic operations apply to phases as wholes and not to parts of them (apart from elements operating at phase EDGES). Once it is complete, it is transferred to PHONETIC FORM and LOGICAL FORM, and thus becomes inaccessible for further operations (the phase impenetrability condition). The notion of phase is similar to that of CYCLE in earlier TRANSFORMATIONAL grammar.