It is a phoneme that exhibits considerable variation in Spanish, which goes from its possible assibilation
(which implies pronouncing it as [z] or [[?
The form puhkea- can be explained as the outcome of an irregular assibilation
in Pre-PFi (*pucki-ta >> *puski-ta > PFi *puhke-da-).
Vasquez-Carranza (2006) reports the same assibilation process for word-medial complex dr onset clusters after a voiced sonorant coronal (l or n), as in vendra ('he/she will come') and saldre ('I will go out').
assibilation of taps before consonants in /rC/ cluster in coda position before consonants with the same voicing value
According to him, forms with non-palatalised [k] survived in the North not because of being unaffected by assibilation, but due to the influence of Scandinavian, a language then characterised by lack of palatalisation.
However, he identified the effect of assibilation, the affricate [tf], word-medially in Northumberland, thus partly supporting Luick's hypothesis.
The article demonstrates that there exist several logically possible assibilation
types that are ruled out because they would involve illicit rankings.
Rissell, Dorothy 1989 "Sex, Attitudes, and the Assibilation
of /r/ among Young People in San Luis Potosi, Mexico".
Instead, the Mari word must have been borrowed from Permic, where an assibilation
of the affricate (*c > *[?
The analysis of the Spanish data produced by speakers from the Costa Rican Central Valley evidenced that the trill has been substituted by an assibilated rhotic, while the tap also undergoes assibilation
in three contexts: 1) in complex /tr/ onset clusters, 2) word-medially in complex onsets that come after a voiced coronal /l/ or /n/, and 3) in /rC/ clusters where the rhotic is in coda position, always before one or more bound clitic morphemes.
of the dental before the high vowel, the i in unprotected final position elided.
So far as I see now, cogent evidence for the assibilation
of word-initial *t before *i in Hittite is lacking, and Pisani's (1969, 266-68) observation that the process in Hittite, as in non-Doric Greek (type rooic, etc.