The mediums of spoken language and signed languages are quite contrast: vocal-aural and visual-spatial, respectively. Yet, every feature in linguistics is also found in signed language. Furthermore, neuroscience studies show that both function in the same linguistic-specific regions of the brain!
In other word, speech is not central to language.
Learn about the language structure of American Sign Language from the smallest units of language (phonology) to the full-fledged structure of language and how it is used in social settings (sociolinguistics).
Linguistics is the scientific study of natural language, including its studies in history, structure, and acquisition of language. It is concerned with the fundamental questions of what language is. Where do languages come from? How do they evolve? How is language structured?
Linguists are interested in inspecting to understand why human language is the way it is. They also seek to determine what unique and universal properties of all human languages are.
Dr. William Stokoe first discovered linguistics in American Sign Language in the 1960s at Gallaudet University in Washington, D.C. Ever since, sign language linguistics has been a strong growing field worldwide.
Linguistics studies in speech language and sign language can be mutually beneficial in many ways, in which established linguistics in speech language can share with a development of linguistics in sign language. On the other hand, linguistics in sign language can sometimes challenge or redefine theories of language. It also can help discover more properties in language that might be overlooked before. Linguistics give us an insight into the structure of the human mind regardless of languages and modalities.
Linguistics is an umbrella of some of the following branches of linguistics.
Phonology is the study of phonemes or the smallest units of a language. It is concerned with how units or phonemes are organized in a language, how they are combined to form a word, and how these phonemes interact with each other.
Phonemes are equivalent to "parameters" and "primes" in sign language, but the term phonology is used in sign language linguistics. Linguists inspect phonological rules of languages.
Morphology is the study of the formation and inflection of words (or morphemes). It studies how morphemes (the smallest units of meaning) are combined to form words from components such as roots and suffixes. For example, the word dogs contains two morphemes dog and the plural s.
Morpheme is the smallest meaningful unit of a language. It's composed of phonemes or parameters, the smallest units of sound or "visue" respectively.
Syntax is the study of sentence structure in a language. It describes a combination of words to form sentences. The subject-action-object order is an example of the structure in English.
Grammar: the system of structural rules which describes how words combine with each other to form sentences.
Semantics is the study of meaning in language. Why do words change? How words are used to represent meanings?
Pragmatics is the study of meaning in context. It deals with how a meaning depends on the context of its use.
Sociolinguistics is the study of relationship of language and social structure, and linguistic variation. Variation.
Language acquisition examines how humans learn to speak and how they learn a second language.
Phonetics is the study of the production (utterance) and perception (listening) of speech sounds in spoken language and signing visues in signed language. It is concerned with how people vocally or manually speak and understand speech or signing respectively. Why one word (whether signed or spoken) is pronounced in this way? Why do people vocally speak with manual gesture or manually speak with vocal gesture? Why do people have different accents?
Also see phonology in sign language.