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I (1) The symbol for intensity (2) The symbol used to represent the palatality element. Sounds made by raising the front of the tongue contain this element.
Iambic reversal [aɪˈæmbɪk] Another name for stress shift.
Ideophone [ˈɪdiəʊfəʊn] A word or other linguistic form whose sound is supposed to represent the concept involved.
Idiolect [ˈɪdiəʊlekt] See lect.
Implicational universal A statement that claims to be true of all human languages and that is of the form: the presence of X implies the presence of Y. A simple example of a phonological implicational universal is: the presence of nasalised vowels in a system implies the presence of non-nasalised vowels.
Implosive [ɪmˈpləʊsɪv] A stop consonant made with an ingressive glottalic airstream mechanism. Implosives which are found in the world's languages are nearly always voiced and combine the above mechanism with a simultaneous pulmonic egressive airstream. Implosives may be produced at a number of places of articulation, including bilabial, alveolar, palatal and velar: [ɓ ɗ ʄ ɠ] . Voiceless implosives have been reported for Kichean languages of Guatemala, though there appears to be a good deal of variation in the phonetic realisation of the sounds concerned. See Pinkerton for further information.
Incus [ˈɪŋkəs] See Anvil.
Indexical [ɪnˈdeksɪkl] A term used to describe a feature of speech which helps to identify or characterise the speaker.
Ingressive [ɪŋˈɡresɪv] A term applied to airstreams. An ingressive airstream is one which moves from outside the vocal tract to the inside. Two ingressive airstreams are used for speech sounds: velaric and glottalic.
Inner ear The innermost cavity of the ear which contains the cochlea.
Initiation The process of setting an airstream in motion for the purpose of producing speech.
Initiator A part of the vocal tract which moves to set an airstream in motion. See also airstream mechanism.
Intensity (Symbol: I )The intensity of a sound is defined as the acoustic power of the sound per unit area compared to a fixed reference. For the purposes of speech and hearing research the reference level is the threshold of human hearing: 10^-12watts/m².
Interarytenoid muscle [ˌɪntərˌærɪˈtiːnɔɪd] A muscle which connects the two arytenoid cartilages. It consists of two components: the transverse arytenoid muscle, which runs horizontally across the rear face of the cartilages, and the oblique arytenoid muscles, which overlay the transverse muscle in the shape of an X. The contraction of the interarytenoid muscle is responsible for the adduction of the vocal folds.
Interdental See dental
Intermediate phrase See prosodic hierarchy.
Intervocalic [ˌɪntəvəʊˈkælɪk] In between two vowels. An example of an intervocalic consonant is the second consonant in the English word riding.
Intonation The use of pitch variation in phrases and sentences to signal such things as speaker attitudes, sentence type (e.g. statement vs question), and information structure. Intonation is different to lexical tone, in that it does not signal differences of word meaning, but contributes to the interpretation of utterances
Intonation(al) phrase See prosodic hierarchy.
Intonational tone A pitch feature which is part of an intonation pattern. The term is opposed to lexical tone. The latter has the word as its domain. The former is the property of a phrase or longer utterance.
Intrinsic allophone An allophone of a phoneme which may be explained principally by reference to phonetic features of the environment in which occurs. An example is the dental allophone [n̪] of the /n/ phoneme in English. This only occurs immediately before a dental fricative. See also extrinsic allophone.
Intrusive /r/ A feature of many accents of English where a sequence of a non-high vowel and any following vowel is broken up by the insertion of /r/, even though this /r/ has no historical justification and does not appear in the spelling. An example: The idea of it → [ði aɪˈdɪər əv ɪt]. See also linking /r/.
Inverse Square Law The physical law which states that the intensity of a sound decreases in proportion to the square of the distance between the source and the point of detection of the sound. Thus, for example, a sound which is detected at x (1 metre away from the source) and at y (3 metres away from the source) will be nine times more intense at x than it is at y.
IPA Either International Phonetic Association or International Phonetic Alphabet.
Isochronicity [ˌaɪsɒkrəˈnɪsəti (adj. isochronous [aɪˈsɒkrənəs]) The tendency for linguistic forms, especially syllables or feet, to have approximately the same duration as other similar forms in their environment.
Isogloss [ˈaɪsəʊɡlɒs] A line drawn on a map separating two geographical areas where the pronunciation of some linguistic form (a vowel, consonant, word etc) differs from one area to the other.