(1) This general term is applied in phonetics and psycholinguistics to the temporal constraints on the articulation and sequencing of sounds in speech production. Timing phenomena are therefore of relevance for an understanding of both segmental and suprasegmental phonetics and phonology: timing is involved in the co-ordination of musculature required to produce an individual sound, in the programming of phonotactic sequences, and in such notions as rhythm and intonation.
(2) The term is also found in some hierarchical models of phonology, as the name of a tier of representation (though its application varies among theories). In particle phonology, for example, the timing tier represents syllable weight (moras). In autosegmental phonology it describes a specific conception of the skeletal tier.