the Latin/Romance of Africa Proconsularis shared an identical five-vowel system (probably /a, ɛ, i, ɔ, u/) with Sardinian. Augustine of Hippo's testimony on how ōs ("mouth") in Latin was to African ears indistinguishable from ŏs ("bone") indicates the merger of vowels and the loss of the original allophonic quality distinction in vowels. Analysis of inscriptions and non-literary documents, including the 3rd century Bu Njem ostraca and Albertini Tablets demonstrate that, despite the presence of other common Vulgar Latin sound changes (such as loss of aspirate h, monophthongization of ae and loss of final m), confusion between ē and ǐ and ō and ŭ is almost nonexistent. Adams finds that inscriptions display a rate of ē/ǐ and ō/ŭ mistakes of only 0.7%, while in the Bu Njem ostraca ē/ǐ and ō/ŭ confusion is totally absent and in the Albertini Tablets there are fewer than two of each error. In contrast, by the 6th-7th c. inscriptions from Gaul show that misspellings of ē/ǐ had come to surpass instances of correct spellings, with an error rate of 51% Data by Adamik shows very slightly higher rates of confusion in Africa Proconsularis (5.3%), but still far lower than in Gaul (63.5%) or Hispania (21.3%), and he similarly concludes that "the later Latin of Africa Proconsularis undoubtedly belonged to the Sardinian Romance type of vocalism." In Latin loanwords in Berber, Latin short ĭ, ŭ also result in i, u (instead of e, o) as in Sardinian. For example, pullus ("chicken") > afullus, cicer ("chickpea") > i-kīkər, pirus ("pear tree") > ti-firest. However, as Adams points out, assumptions about African Romance vocalism based solely on loanwords should be taken with caution due to the lack of vowels /e, o/ in Berber languages. On the contrary, Adamik states that data from inscriptions show that the vowel system of the western province of Mauretania Caesariensis seemed to be developing differently from that of Africa Proconsularis/Sardinia. Due to a higher number of ē/ǐ confusions found than ō/ŭ confusions (at 4.6% vs. 1.3%), it is suggested that the vocalic system of Mauretanian Latin might possibly "have started to develop toward the eastern or Balkan (more exactly Rumanian) type of vocalism": e.g., merging ē with ĭ, ĭ with ī and ŭ with ū, potentially resulting in the six-vowel system /a, ɛ, e, i, o, u/. However, spelling error rates are still too low for a definite conclusion to be made on