other voiced sounds, became voiced: /p/ > /b/, /t/ > /d/, /k/ > /g/, /t͡ʃ/ > /d͡ʒ/ This process is thought not to have been taken place before Sassanid Pahlavi, and it generally isn't reflected in Pahlavi spelling. A further stage in this lenition process is expressed in a synchronic alternation: at least at some stage in late Middle Persian (later than the 3rd century), the consonants /b/, /d/, /g/ appear to have had, after vowels, the fricative allophones [β], [ð], [ɣ]. This is slightly more controversial for /g/, since there appears to have been a separate phoneme /ɣ/ as well. A parallel development seems to have affected /d͡ʒ/ in the same position, possibly earlier; not only was it weakened to a fricative [ʒ], but it was also depalatalised to [z]. In fact, old Persian [dʒ] and [ʒ] in any position also produced [z]. Unlike the case with the spirantisation of stops, this change is uncontroversially recognised for Sassanid times. The lenition of voiceless stops and affricates remained largely unexpressed in Pahlavi spelling, which continues to reflect the Arsacid sound values, but is known from the more phonetic Manichaean spelling of texts from Sassanid times. Arsacid šap > Sassanid šab (late [ʃaβ]) 'night' (Pahlavi LYLYA, šp'; Manichaean šb) Arsacid pit > Sassanid pid (late [pið]) 'father' (Pahlavi AB, p(y)t', Manichaean pyd) Arsacid pārak > Sassanid pārag (late [paːraɣ]) 'gift' (Pahlavi pʾlk') Arsacid hač > Sassanid az 'from' (Pahlavi MN, hc, Manichaean ʾc or ʾz) As a result of these changes, the voiceless stops and affricates /p/, /t/, /k/, /t͡ʃ/ rarely occurred after vowels – mostly when geminated, which has protected them from the lenition (e.g. waččag, sp. wck' 'child'), and due to some other sound changes. Another difference between Arsacid and Sassanid-era pronunciation is that Arsacid word-initial /y/ produced Sassanid /d͡ʒ/ (another change that is not reflected in the Pahlavi spelling). The sound probably passed through the phase /ʒ/, which may have continued until very late Middle Persian, since Manichaean texts did not identify Indic /d͡ʒ/ with it and introduced a separate sign for the former instead of using the letter for their native sound. Nonetheless, word-initial /y/ was retained/reintroduced in learned borrowings from Avestan. Arsacid yām > Sassanid ǰām 'glass' (Pahlavi yʾm, Manichaean jʾm); but: Avestan yazata > Middle Persian yazd 'god' (Pahlavi yzdt') Furthermore, some forms of Middle Persian appear to have preserved ǰ (from Proto-Iranian /d͡ʒ/ or