Phonetic Laws

in linguistics, regular changes that occur during the development of a language in its sound structure (compare the disappearance of the vowels 2 and b in Russian) or in the phonetic structure of words (compare the replacement of e by o in Russian; for example the present-day nes [nyos] “he carried” from the old nes [nyes]). Spontaneous and combinative changes are distinguished from each other; the former occur in all instances where a corresponding sound is encountered; for example, in Russian?? has been replaced in all positions by the vowel e. The second type of change occurs only in certain phonetic positions; thus, the replacement of e by o took place only in the stressed syllable, if a hard consonant followed the e (compare podennyi, “daily,” with den’, “day”). The study of phonetic laws has been most fully developed by the German school of neogrammarians. Their theory was disputed by J. N. Baudouin De Courtenay and others, whose criticism was directed against the thesis of the stability of phonetic laws and the exaggeration of their role. With the development of phonology came historical, or diachronic, phonology, in which phonetic laws were examined in the aspect of the study of the phoneme.