Definition - The non-phonemic but vocal aspects of speech, such as voice tone and speech tempo, that are used to enhance communication.

1. Some authorities also include gestures and facial expressions as part of its purview.

Example -

(1) What do you want? (the tone indicates a question)
(2) What do you #$@$#$ want! (the tone indicates anger)

Etymology -
According to G. L. Trager in Studies in Linguistics XIII, the term was suggested by A. A. Hill. It derives from the Greek para, beside + language.

Oxford English Dictionary -
Its first citation is from 1958:
"The vocalizations and voice qualities together are being called paralanguage (a term suggested by A. A. Hill)."
(G. L. Trager in Studies in Linguistics XIII. 4 )

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