A tense sound is one that involves a tension in the articulators and is often characterized by a +[ATR] feature. These sounds require greater exertion from the muscles than their lax counterparts. The contrast is exemplified by English vowels /i/ (tense) and /ɪ/ (lax).
Scottish Gaelic distinguishes between tense and lax sonorants.
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- Matthews, P. H. (1997) The Concise Oxford Dictionary of Linguistics. Oxford: Oxford University Press.