Final answer:
The study of rules and practices for making and using sounds in a language is a part of linguistics known as phonology, which examines the organization and rules of speech sounds.
Step-by-step explanation:
The study of rules and practices for making and using sounds in a language is called phonology, which is a subfield of linguistics. Linguistics is the scientific study of language, including its form, meaning, and context. This includes different subfields such as morphology, syntax, semantics, pragmatics, sociolinguistics, linguistic anthropology, and others. In phonology, the focus is on the patterns of sounds in a language and the rules that govern these patterns.
Phonology delves into how speech sounds are organized in the mind and how they are expressed through the mouth and heard by the ear. It encompasses both the physical properties of these sounds (phonetics) and the linguistic rules that dictate how they're used to convey meaning in a particular language. For example, the English sound spelled "th" can be represented by either a voiced dental fricative as in this, or a voiceless dental fricative as in thing. These nuances are part of what phonologists' study.
The knowledge of the grammar and lexicon is organized within a language's rules and practices to allow for the dynamic creation and understanding of new and complex ideas. Thus, understanding the rules around language not only provides a means for effective communication but allows insights into cultural and social practices within a given community or region.