Paralanguage, also known as vocalics, is a component of meta-communication that may modify meaning, give nuanced meaning, or convey emotion, by using techniques such as prosody, pitch, volume, intonation, etc. It is sometimes defined as relating to nonphonemic properties only. Paralanguage may be expressed consciously or unconsciously.
The study of paralanguage is known as paralinguistics, and was invented by George L. Trager in the 1950s, while he was working at the Foreign Service Institute of the Department of State. His colleagues at the time included Henry Lee Smith, Charles F. Hockett (working with him on using descriptive linguistics as a model for paralanguage), Edward T. Hall developing proxemics, and Ray Birdwhistell developing kinesics. Trager published his conclusions in 1958, 1960 and 1961.
His work has served as a basis for all later research, especially those investigating the relationship between paralanguage and culture (since paralanguage is learned, it differs by language and culture). A good example is the work of John J. Gumperz on language and social identity, which specifically describes paralinguistic differences between participants in intercultural interactions. The film Gumperz made for BBC in 1982, Multiracial Britain: Crosstalk, does a particularly good job of demonstrating cultural differences in paralanguage, and the impact these have on relationships.
Paralinguistic information, because it is phenomenal, belongs to the external speech signal (Ferdinand de Saussure’s parole) but not to the arbitrary conventional code of language (Saussure’s langue).
The paralinguistic properties of speech play an important role in human communication. There are no utterances or speech signals that lack paralinguistic properties, since speech requires the presence of a voice that can be modulated. This voice must have some properties, and all the properties of a voice as such are paralinguistic. However, the distinction linguistic vs. paralinguistic applies not only to speech but to writing and sign language as well, and it is not bound to any sensory modality. Even vocal language has some paralinguistic as well as linguistic properties that can be seen (lip reading, McGurk effect), and even felt, e.g. by the Tadoma method.
Aspects of the speech signal
Speech signals arrive at a listener’s ears with acoustic properties that may allow listeners to identify location of the speaker (sensing distance and direction, for example). Sound localization functions in a similar way also for non-speech sounds. The perspectival aspects of lip reading are more obvious and have more drastic effects when head turning is involved.
The speech organs of different speakers differ in size. As children grow up, their organs of speech become larger and there are differences between male and female adults. The differences concern not only size, but also proportions. They affect the pitch of the voice and to a substantial extent also the formant frequencies, which characterize the different speech sounds. The organic quality of speech has a communicative function in a restricted sense, since it is merely informative about the speaker. It will be expressed independently of the speaker’s intention.
Paralinguistic cues such as loudness, rate, pitch, pitch contour, and to some extent formant frequencies of an utterance, contribute to the emotive or attitudinal quality of an utterance. Typically, attitudes are expressed intentionally and emotions without intention, but attempts to fake or to hide emotions are not unusual.
Ordinary phonetic transcriptions of utterances reflect only the linguistically informative quality. The problem of how listeners factor out the linguistically informative quality from speech signals is a topic of current research.
Some of the linguistic features of speech, in particular of its prosody, are paralinguistic or pre-linguistic in origin. A most fundamental and widespread phenomenon of this kind is described by John Ohala as the “frequency code”. This code works even in communication across species. It has its origin in the fact that the acoustic frequencies in the voice of small vocalizers are high while they are low in the voice of large vocalizers. This gives rise to secondary meanings such as ‘harmless’, ‘submissive’, ‘unassertive’, which are naturally associated with smallness, while meanings such as ‘dangerous’, ‘dominant’, and ‘assertive’ are associated with largeness. In most languages, the frequency code also serves the purpose of distinguishing questions from statements. It is universally reflected in expressive variation, and it is reasonable to assume that it has phylogenetically given rise to the sexual dimorphism that lies behind the large difference in pitch between average female and male adults.