Some linguists have referred to
grooved fricatives, a similar but distinct articulatory concept, as
sulcalized, though this should not be confused with the more common definition described in the section above. As with the more common definition of sulcalization, grooved fricatives also involve forming a groove down the center of the tongue (such as in some realizations of in the
English words
sit and
case). They contrast with
slit fricatives, which are pronounced with the tongue flat.
Distinction The grooved–slit distinction primarily applies to
anterior consonants. Unlike the more common definition of sulcalization, which typically refers to a posterior hollowing, grooved fricatives involve raising the sides of the tongue to focus the turbulent airstream on the teeth, producing an anterior hollowing. This results in a more intense sound, typically associated with
sibilants. Slit fricatives, with a flatter shape, have a wider and more dispersed airflow channel.
Phonetic status J. C. Catford observed that the degree of tongue grooving differs between
places of articulation as well as between languages; however, no language is known to phonemically contrast fricatives based purely on the presence or absence of tongue grooving. Nonetheless, linguists sometimes make a phonetic distinction for certain fricative allophones that occur at the same place of articulation as a grooved or slit counterpart. For example, (a
lenited allophone of found in some English dialects) is commonly described as slit, to distinguish it from grooved ; though it has also been noted that additional articulatory factors may go into the distinction between grooved and slit . Historically, the terms
grooved fricative and
sibilant have sometimes been used synonymously (and by extension,
slit fricative and
non-sibilant), though the reality of
sibilant shapes is more complex; not all sibilants may share this feature, nor may it be unique to sibilants. For instance, is widely regarded to be characterized by a convex doming of the tongue rather than a concave grooving, and therefore has been defined as slit; conversely, ultrasound imaging has shown in English to exhibit grooving similar to , despite being typically regarded as slit.
Transcription practices It was once proposed for the
IPA to include a diacritic to distinguish grooved and slit fricatives, but the proposal was rejected. While lacking diacritics for the feature specifically, the
extIPA chart includes and to denote slit alveolar fricatives, which the authors have noted form a contrastive graphical pair with the more commonly seen and , denoting grooved dental fricatives. ==See also==