Sībawayh describes /q/, /ṭ/, /b/, /ǧ/ and /d/ as [+ voiced + stop] phonemes. In pausal position, these phonemes are subject to qalqala, which can be described as the addition of a schwa [ə], and whose role is the proctection of the [+ voiced] feature of these phonemes. In standard Classical Arabic, the pronunciation of these phonemes has evolved (/q/ and /ṭ/ are now realised as [- voiced], and /ǧ/ as [+ affricate]). The consistency of qalqala as described by Sībawayh is thus lost, since the Qurʾānic recitation (taǧwīd) rule for qalqala does not fit the current standard pronunciation.
In this study, we trace back a shift in the mere definition of qalqala as early as in al-Mubarrad’s Muqtaḍab that will enable Qurʾānic reciters to later remain blind to the fact that their actual pronunciation of some of these phonemes does not correspond to Sībawayh’s written description.