Читать книгу Applying Phonetics - Murray J. Munro - Страница 16

When phoneticians talk about speech, they mean the component of language conveyed by sound. Speech is rooted in human biology in that it is produced through the centrally mediated (i.e., managed by the brain) activity of the vocal tract. Of course, many animals can make non‐speech sounds, so to understand what makes speech special, we need to consider its relation to other communication types. Figure 1.1 shows some of the ways that different types of communication may be classified. Broadly, communication refers to an exchange of information between organisms. The first thing to notice is that some communicative behaviors count as linguistic and some do not. This distinction is shown on the horizontal dimension of the figure. Language is an elaborate symbolic system that can be used to convey all sorts of information from one person to another. But many kinds of information can certainly be conveyed without it. Animals often send messages, for example, using body postures and movements, cries and roars, and even odors. Linguists would generally agree that none of these forms of expression counts as language. Humans, too, can convey a great deal of useful information without language. Babies express emotional states like discomfort, frustration, and pleasure through cries, giggles, and other vocalizations, and through facial expressions that are not linguistic either. Most of the time, classifying something as language or not is straightforward, yet a fully satisfactory technical definition of language has proved surprisingly elusive. We will return to this issue shortly.

Figure 1.1 Classification of communication types

A second dimension of communication—shown on the vertical dimension of Figure 1.1—concerns whether or not a vocal tract is involved. Across animal species, many forms of non‐vocal communication are possible. Some of these appear to be simple, as when a dog leaves its signature by urinating on a fire hydrant or a cat rubs the side of its head against a piece of furniture, leaving a scent marking. These signs are primitive in that they transmit relatively little information (“I've been here!”) and are not directed at any particular receiver. Other examples of non‐vocal communication, however, are information‐rich and geared to a specific, interested audience. Bees perform an elaborate “dance” in view of the other members of their hive, using a sophisticated non‐vocal system that informs the community of both the location and the quality of a food source, and does so with a high degree of precision.

Human non‐vocal communication varies in its complexity as well. A gentle touch with a hand can be understood as an affectionate act, and facial expressions can reveal a wide range of emotional states. More impressively, human non‐vocal behavior is sometimes linguistic. This is because human language has more than one means of transmission or MODALITY. The vocal modality is the one we call speech, but the written modality is used for books, computer documents, emails, and text messages. While the written and vocal modalities have a great deal in common, they also differ in important respects. For instance, when we talk, we usually don't use the same level of formality and the same vocabulary as we do when writing a business memorandum. And when we write, we are not able to take advantage of certain aspects of spoken language that affect how our ideas are conveyed, such as changes in tempo, loudness, or pitch.

In addition to the vocal and written forms of language, another modality is gesture, a means by which well over 100 distinct languages, including American Sign Language (ASL ), Japanese Sign Language (Nihon Suhwa), and Spanish Sign Language (Lengua de Signos Española), are transmitted. Sign systems are exceptional among human languages in that they do not use sound at all; however, they are every bit as complex and nuanced as spoken languages.

Tetrapods are creatures that evolved from four‐footed ancestors. Note that tetrapods themselves do not necessarily have four feet. In fact, snakes and birds are tetrapods because their evolutionary predecessors were four‐footed reptiles. And all mammals, including humans, are tetrapods as well.

Vocal communication, shown in the middle row of Figure 1.1, entails the production of sound using parts of the body that are also used for breathing and eating. While many animals, including humans, can vocalize, not all their sounds fall into this category. Crickets chirp or stridulate by rubbing parts of their wings against each other, and humming birds hum because of rapid movements of their wings. But virtually all tetrapods have a LARYNX, a structure in the upper part of the body that serves a variety of purposes and happens to make vocalization possible. The meow of a cat, the bleating of a goat, and even the hissing of a snake are all the result of exploiting laryngeal structures, together with other parts of the VOCAL TRACT, to create non‐linguistic sounds. When a baby screams out in frustration because it is hungry, it is communicating vocally but non‐linguistically; so too are adults when they sigh, gasp, or clear their throats to attract attention.

Speech, however, is more complicated than these non‐linguistic sounds because it is an expression of what we consider true language. But how do we define language? Doing so in a succinct way has turned out to be extremely difficult, so linguists have sometimes preferred to focus on certain properties, termed design features by Charles F. Hockett, which, taken together, might capture the difference between language and other communicative systems (Hockett & Hockett, 1960). While we won't go into all of his original 13 features here, four of them that are especially relevant to speech are ARBITRARINESS, DISCRETENESS, PRODUCTIVITY, and DUALITY OF PATTERNING. Human speech is arbitrary in the sense that there is generally no connection between the things that are referred to and the spoken symbols used to represent them, as is true for the words tree (/tɹi/), moon (/mun/), and love (/lʌv/). A non‐English‐speaker hearing these words for the first time would not be able to guess their meanings from the way they sound. In fact, two different languages sometimes assign the same sequence of sounds to entirely different meanings. For instance, the Japanese word for tree happens to be /ki/, pronounced like the English word key.

Discreteness refers to our interpretation of the speech signal as a sequence of individual segments, which makes it possible to structure words and other linguistic units in terms of smaller chunks. These PHONES are familiar to us as vowels and consonants, and they occur in every language. Next, productivity accounts for our ability to arrange these phones in countless different orders to convey distinct meanings. A simple example is our ability to analyze the word cat as a series of three phones represented as /k/, /æ/, and /t/ in the INTERNATIONAL PHONETIC ALPHABET. Note that we can arrange the same sounds in two other orders that have distinct meanings:

 /t/ + /æ/ + /k/ gives us the sequence /tæk/, spelled as tack. (Don't be misled by the spelling!)

 /æ/ + /k/ + /t/ gives us the sequence /ækt/, spelled act.

The last of the four features, duality of patterning, is closely related to discreteness and productivity and refers to the way spoken languages make use of a system of sounds that relate to a system of meanings. While the individual phones of a language are typically meaningless on their own, they can be combined in orderly ways for communicative purposes. When we say that they work as a system, we mean that within a particular language there are restrictions on how they can be combined. In English, for instance, we can't have */tkæ/, */ætk/, or any other words starting or ending with /tk/. However, we can use an additional property of our language to systematically change meanings: we add /s/ to cat, tack, and act to create the plural form of each. The four phones we've mentioned occur in thousands of other words. In fact, the remarkable consequences of discreteness, productivity, and duality of patterning become clear when we realize that English has only about 35–38 phones (depending on the dialect), which can be combined to create a vocabulary of perhaps a million words. What's more, it is perfectly possible to use new combinations of phones to invent new words. As far as I know, splenk (/splɛŋk/) is not an English word, but there is nothing to stop an inventor from developing a new household tool and calling it a splenk. And splenk users would realize, without being told, that the plural form of the word is likely splenks!

Linguists use an asterisk (*) to denote a non‐existent word or impossible sound sequence in a particular language.

It is quite easy to pinpoint some of the ways in which non‐human communication systems lack the properties of human language. For instance, the bee dance mentioned earlier expresses the angle of the sun relative to a food source through the angle at which the dance is performed. In that case, there is a connection between the communicative symbol and the thing it stands for, so in that respect bee communication lacks arbitrariness. In a similar vein, there is no evidence of discreteness or productivity in the meowing of a cat; it isn't possible to break a cat vocalization down into smaller pieces and rearrange them to generate new messages.

However, we must not make the mistake of being too categorical in our assessments of human versus non‐human communication systems. In the first place, animal vocalizations are not entirely devoid of speech‐like elements. Vervet monkeys, for example, use different vocal alarm calls to alert other members of their group to imminent dangers. Seyfarth, Cheney, and Marler (1980) studied these vocalizations by recording them, analyzing their acoustic composition, and playing the sounds back through loudspeakers while observing the vervets' behavior. The monkeys produced a low‐pitched, grunt‐like call, for instance, on the approach of an eagle, and a higher‐frequency call at the sight of a snake. When other vervets were exposed to only the recorded calls with no visual stimuli, they responded as if an eagle or snake were present. On the one hand, the alarms apparently aren't divisible into smaller units, and there is no indication that vervets can rearrange the sounds of one call to create another call with a different meaning. Consequently, the vervet vocalizations can be said to lack discreteness and productivity. But, on the other hand, the calls do have the speech‐like property of arbitrariness: there appears to be no connection between the sounds and the things they represent. In that respect, they share something with human speech.

A second observation is that human speech does not fully conform to the design features we've mentioned. For one thing, not all aspects of speech are arbitrary. English, and presumably all other languages, has scores of onomatopoeic words like bang, burp, chirp, and clap, which sound to some degree like the things they refer to. Research has also uncovered intriguing examples of SOUND SYMBOLISM, in which particular speech sounds are associated with certain meanings (Westbury, Hollis, Sidhu, & Pexman, 2018). For instance, in linguistic judgment tasks, people tend to link the sounds /k/ and /t/ to the concept of sharpness, while /m/ and /l/ suggest roundness. These and other non‐arbitrary mappings may be much more than trivial matters. Some evidence indicates that they may facilitate child language acquisition. We will return to this topic when we discuss its applicability in the complexities of product naming in Chapter 14.