No two people speak exactly alike. Differences in age, sex (women have smaller larynxes than men), family background, education, class, and geographical provenience all leave their imprint on individual language use. The ensemble of features making up a person’s speech are signified by the term IDIOLECT. Each member of a speech community, moreover, typically belongs to a social group whose speech is uniform enough to be characterized in its ensemble by the term SOCIOLECT. There is also a stratification of sociolects, encompassing particularities of speech that owe their origins to social and regional dialects even as speakers in a particular sociolect still adhere to the linguistic norm set down in industrialized societies by the spread of standard languages through increasing literacy and the uniformity promoted by media language.
If one takes the viewpoint of an attentive listener or interlocutor, who is alternately silent while fulfilling the role of a conversation partner, then the linguistic behavior of the speaking participants can be observed in all their semiotic plenitude. This includes not only pronunciation of speech sounds (phonetics proper) and choice of vocabulary (including verbal tics) but variable suprasegmental features (such as intonation) as well as peculiarities of speech production (mush-mouthedness, lisps, vocal timbre and register, etc.).
Beyond language sensu stricto are the gestural features––those termed PARALINGUISTIC––that invariably accompany speech: (1) acoustic manifestations like sips (intakes of breath), sighs, grunts, and various other sounds; (2) bodily movements, including shrugs, arm and hand gestures, head bobs and inclines; lip, mouth, eye, and forehead movements, etc. In some languages these paralinguistic features are completely codified and have practically univocal interpretations, e. g., the sharp intake of breath in Japanese through the lips and teeth that signifies doubt or hesitation; or the typically less abrupt intake through the mouth in the Scandinavian languages accompanying some statements, especially those with concessive meaning.
The upshot of each person’s having an idiolect goes far beyond its practical utility (as in speech recognition protocols) and plays a salient role in interpersonal relations. Consciously or not, our EVALUATION of persons with whom we interact is differentially contingent on their speech traits in the round. Depending on the importance we attach to how our interlocutors speak the language we share, their prestige in our eyes generally rises and falls in the degree to which THEY SPEAK LIKE US.