Sulcalization (fromLatin:sulcus 'groove'), inphonetics, is the pronunciation of a sound with a deep, longitudinal concavity (groove) down the back of thetongue (the dorsum), roughly opposite of theuvula.[1] This is accomplished by raising the sides of the dorsum, and leaving a hollow along the mid-line.[2][3]
This articulation has typically been associated withrhotics such as a 'bunched' or 'molar'[ɹ̈][4][5] andr-colored vowels,[6][7][1] as well as 'dark' or 'throaty' quality sounds,[3] either morevelar-like (such as[ɫ])[2][8] or morepharyngeal-like (such as[ɒ]).[9][10]
No spoken language is known to make aphonemic distinction between sulcalized and ordinary vowels;[3] though it has been reported that for some speakers ofReceived Pronunciation, the vowel/ɒ/, which is normally described asrounded, is pronounced with spread lips, and is instead given its characteristic quality through a "hollowing or sulcalization of the tongue-body."[9] One scholar has also suggested that the vowel in the RP pronunciation of words likebird, typically transcribed/ɜ/, is actually a sulcal schwa, retaining the sulcality of the original rhotic consonant. Accordingly, the realization of the/ə/-element of the centring diphthongs/ɪə̯/,/ʊə̯/,/ɛə̯/ in words such asnear,pure andscare, is interpreted as the product of a loss of sulcality.[7]
Some linguists have referred togrooved fricatives, a similar but distinct articulatory concept, assulcalized,[11] though this should not be confused with the more standard definition described in the section above. Contrasting withslit fricatives, which are pronounced with the tongue flat,grooved fricatives also involve forming a groove down the center of the tongue (such as in some realizations of/s/ in theEnglish wordssit andcase).[11]
Unlike the more standard definition ofsulcalization, grooved fricatives involve the sides of the tongue focusing the airstream on the teeth, producing a more intense sound, typically associated withsibilants.[12]J. C. Catford observed that the degree of tongue grooving differs between places of articulation as well as between languages;[13] however, no language is known to contrast sibilants based purely on the presence or absence of tongue grooving.
/θ/ has been reported to show tongue grooving in English, despite being typically regarded as slit.[14]