Which study investigates the rules and patterns of speech sounds?

Phonology is the branch of linguistics that focuses on the systematic organization of sounds in languages. It studies how speech sounds function and pattern within particular languages, as well as the rules that govern speech sounds and their combinations. This includes an analysis of sound systems, including consonants and vowels, and features such as stress, intonation, and the phonetic variations that can occur in different contexts.

In contrast, morphology deals with the structure and formation of words; pragmatics focuses on the context of language usage and its effects on meaning; and syntax examines the rules and principles that govern sentence structure. Understanding phonology is crucial for linguists and anthropologists who analyze language as a cultural element, as it reveals how different languages utilize sound to convey meaning and identity within communities.