See data and maps.
Moroz, G. (2021). “Labialization”. In: Typological Atlas of the Languages of Daghestan (TALD). Ed. by M. Daniel, K. Filatov, T. Maisak, G. Moroz, T. Mukhin, C. Naccarato and S. Verhees. Moscow: Linguistic Convergence Laboratory, NRU HSE. DOI: 10.5281/zenodo.6807070. http://lingconlab.ru/dagatlas.
@incollection{moroz2021,
title = {Labialization},
author = {George Moroz},
year = {2021},
editor = {Michael Daniel and Konstantin Filatov and Timur Maisak and George Moroz and Timofey Mukhin and Chiara Naccarato and Samira Verhees},
publisher = {Linguistic Convergence Laboratory, NRU HSE},
address = {Moscow},
booktitle = {Typological Atlas of the Languages of Daghestan (TALD)},
url = {http://lingconlab.ru/dagatlas},
doi = {10.5281/zenodo.6807070},
}
General chapter: Phonology
Labialization is widely attested in East Caucasian languages. However, there are some languages that have lost this feature (e.g. Budukh (Talibov 2007)). Unfortunately, sometimes scholars do not provide a full list of labialized consonants attested in a language, so it is hard to obtain a complete list. Following (Catford 1972) it is worth mentioning that there are several types of labialization:
Labialization is lost in Bezhta, Udi, Budukh and Khinalug. Possibly the absence of labialized consonants in Nakh languages results from a reinterpretation by scholars of the w as forming part of a diphthong. Georgian probably also has labialized consonants, but those cases are analyzed as a combination of a consonant and w.