This Primitive Adûnaic phoneme was a voiceless continuant in the c-series (palatals) (SD/416). Tolkien described it as “a voiceless hissed Y, that is the German ich-laut or a rather stronger form of the voiceless Y often heard initially in such an English word as ‘huge’” (SD/417). Very probably it was the voiceless palatal fricative (IPA [ç]). It became an [s] in Classical Adûnaic along with the other voiceless consonants of the c-series (SD/418).

Tolkien represented this sound with the symbol “2” in the typescript of Lowdham’s Report, probably because he was working on a typewriter. This sound rarely appeared in Tolkien’s languages, so it isn’t clear what symbol he would have used were he writing by hand. The discussion of Adûnaic here uses the IPA symbol “ç” orthographically to represent the sound [ç], but there are no attested words in which it appears. The only attested word in which it may have appeared was the primitive ancestor of sulum, not explicitly given by Tolkien.