Sign phonetics is the study of how sign languages are produced and perceived, by native as well as by non-native signers. Most research on sign phonetics has focused on American Sign Language (ASL), but there are many different sign languages around the world, and several of these, including British Sign Language, Taiwan Sign Language, and Sign Language of the Netherlands, have been studied at the level of phonetics. Sign phonetics research can focus on individual lexical signs or on the movements of the nonmanual articulators that accompany those signs. The production and perception of a sign language can be influenced by phrase structure, linguistic register, the signer’s linguistic background, the visual perception mechanism, the anatomy and physiology of the hands and arms, and many other factors. What sets sign phonetics apart from the phonetics of spoken languages is that the two language modalities use different mechanisms of production and perception, which could in turn result in structural differences between modalities. Most studies of sign phonetics have been based on careful analyses of video data. Some studies have collected kinematic limb movement data during signing and carried out quantitative analyses of sign production related to, for example, signing rate, phonetic environment, or phrase position. Similarly, studies of sign perception have recorded participants’ ability to identify and discriminate signs, depending, for example, on slight variations in the signs’ forms or differences in the participants’ language background. Most sign phonetics research is quantitative and lab-based.
A phonological inventory is a repertoire of contrastive articulatory or manual gestures shared by a community of users. Whether spoken or signed, all human languages have a phonological inventory. In spoken languages, the phonological inventory is comprised of a set of segments (consonants and vowels) and suprasegmentals (stress and intonation) that are linguistically contrastive, either lexically or grammatically, in a particular language or one of its dialects. Sign languages also have phonological inventories, which include a set of linguistically contrastive signs made from movement, hand shape, and location. The study of phonological inventories is interesting because they tell us about the distribution, frequency, and diversity of gestures that individuals acquire and produce in the world’s 7,000 or so languages. Their study has also raised important empirical questions about the comparability of linguistic concepts across different languages and modalities, in the use of statistics and sampling in quantitative approaches to comparative linguistics, and in the study of language ontogeny and phylogeny over the course of language evolution. As such, some recent research highlights include the following: quantitative approaches suggest causal relationships between phonological inventory composition and gene-culture and language-environment coevolution; the study of de novo sign languages provides important insights into the emergence of phonology; and comparative animal communication studies suggest evolutionary speech precursors in phonological repertoires of nonhuman primates, and potentially in extinct hominids including Neanderthal.
D. H. Whalen
Phonetics is the branch of linguistics that deals with the physical realization of meaningful distinctions in spoken language. Phoneticians study the anatomy and physics of sound generation, acoustic properties of the sounds of the world’s languages, the features of the signal that listeners use to perceive the message, and the brain mechanisms involved in both production and perception. Therefore, phonetics connects most directly to phonology and psycholinguistics, but it also engages a range of disciplines that are not unique to linguistics, including acoustics, physiology, biomechanics, hearing, evolution, and many others. Early theorists assumed that phonetic implementation of phonological features was universal, but it has become clear that languages differ in their phonetic spaces for phonological elements, with systematic differences in acoustics and articulation. Such language-specific details place phonetics solidly in the domain of linguistics; any complete description of a language must include its specific phonetic realization patterns. The description of what phonetic realizations are possible in human language continues to expand as more languages are described; many of the under-documented languages are endangered, lending urgency to the phonetic study of the world’s languages. Phonetic analysis can consist of transcription, acoustic analysis, measurement of speech articulators, and perceptual tests, with recent advances in brain imaging adding detail at the level of neural control and processing. Because of its dual nature as a component of a linguistic system and a set of actions in the physical world, phonetics has connections to many other branches of linguistics, including not only phonology but syntax, semantics, sociolinguistics, and clinical linguistics as well. Speech perception has been shown to integrate information from both vision and tactile sensation, indicating an embodied system. Sign language, though primarily visual, has adopted the term “phonetics” to represent the realization component, highlighting the linguistic nature both of phonetics and of sign language. Such diversity offers many avenues for studying phonetics, but it presents challenges to forming a comprehensive account of any language’s phonetic system.
Irit Meir and Oksana Tkachman
Iconicity is a relationship of resemblance or similarity between the two aspects of a sign: its form and its meaning. An iconic sign is one whose form resembles its meaning in some way. The opposite of iconicity is arbitrariness. In an arbitrary sign, the association between form and meaning is based solely on convention; there is nothing in the form of the sign that resembles aspects of its meaning. The Hindu-Arabic numerals 1, 2, 3 are arbitrary, because their current form does not correlate to any aspect of their meaning. In contrast, the Roman numerals I, II, III are iconic, because the number of occurrences of the sign I correlates with the quantity that the numerals represent. Because iconicity has to do with the properties of signs in general and not only those of linguistic signs, it plays an important role in the field of semiotics—the study of signs and signaling. However, language is the most pervasive symbolic communicative system used by humans, and the notion of iconicity plays an important role in characterizing the linguistic sign and linguistic systems. Iconicity is also central to the study of literary uses of language, such as prose and poetry. There are various types of iconicity: the form of a sign may resemble aspects of its meaning in several ways: it may create a mental image of the concept (imagic iconicity), or its structure and the arrangement of its elements may resemble the structural relationship between components of the concept represented (diagrammatic iconicity). An example of the first type is the word cuckoo, whose sounds resemble the call of the bird, or a sign such as RABBIT in Israeli Sign Language, whose form—the hands representing the rabbit's long ears—resembles a visual property of that animal. An example of diagrammatic iconicity is vēnī, vīdī, vīcī, where the order of clauses in a discourse is understood as reflecting the sequence of events in the world. Iconicity is found on all linguistic levels: phonology, morphology, syntax, semantics, and discourse. It is found both in spoken languages and in sign languages. However, sign languages, because of the visual-gestural modality through which they are transmitted, are much richer in iconic devices, and therefore offer a rich array of topics and perspectives for investigating iconicity, and the interaction between iconicity and language structure.