This article deals with the phonology of Avestan. Avestan is one of the Iranian languages and retained archaic voiced alveolar fricatives. It also has fricatives rather than the aspirated series seen in the closely related Indo-Aryan languages.
According to Beekes, and are allophones of /ø/ and /x/ respectively(in Old Avestan).
Avestan ṣàcontinues Indo-Iranian *-rt-. Its phonetic value and its phonological status (one or two phonemes) are somewhat unclear. The conditions under which change from -rt- to -á¹£ÃÂ- occurs are fundamentally ill-defined, though it is likely to occur if the preceding vowel is accented. Thus, for example, Gathic/Younger ÃÂrÃÂta/arÃÂta ('establish') is a variant of aá¹£ÃÂa but is consistently written with r t/. Similarly, arÃÂti ('portion') and aà ¡i ('recompense'). But amÃÂá¹£ÃÂa ('immortal') is consistently written with á¹£ÃÂ, while marÃÂta ('mortal') is consistently written with r t. In some instances, a change is evident in only Younger Avestan. For example, the Gathic Avestan word for "bridge" is pÃÂrÃÂtà «m, while in Younger Avestan it is pÃÂá¹£ÃÂà «m. Both are singular accusative forms, but when the word is singular nominative, the Younger Avestan variant is again (and all but once) with r t.
Benveniste suggested ṣàwas only a convenient way of writing /rt/ and should not be considered phonetically relevant. According to Gray, ṣàis a misreading, representing /r r/, of uncertain phonetic value but "probably" representing a voiceless r.
Miller follows the older suggestion that Avestan ṣàrepresents a phoneme of its own, for which he introduces the symbol "/à Â/" and identifies phonetically as (the voiceless allophone of Czech à Â). He goes on to suggest that in writing, -rt- was restored when a scribe was aware of a morpheme boundary between the /r/ and /t/.
There are various conventions for transliteration of the Avestan alphabet. We adopt the following one here. Vowels:
Consonants:
The glides y and w are often transcribed as ii and uu, imitating Avestan orthography. The letter transcribed tð indicates an allophone of with no audible release at the end of a word and before certain obstruents.