noun /fəˈnɒlədʒi,fəˈnɑlədʒi/
a) The study of the way sounds function in languages, including phonemes, syllable structure, stress, accent, intonation, and which sounds are distinctive units within a language.
The Achean, the ancient Malayu and other mixed phonologies possessing a considerable degree of harshness, were thus formed.
b) The way sounds function within a given language.
Crucially, the neat separateness of phonologies which my account seems to imply is an abstraction and does not mean that the phonologies represented different regional or social dialects.
See Also: phonetics
Wikipedia foundation.