This paper deals with a new type of tonogenesis in the Tibetic languages spoken in the eastmost Tibetan area, i.e. Sichuan-Gansu border area, based on my first-hand data. The members of the Eastern Tibetic languages are: Cone (kLuchu + Nyinpa), Thewo (stod + smad), mBrugchu (Ongsum + dGonpa), dPalskyid (dPalskyid + Babzo), Khodpokhog (gZitsakhog + nKhyungkyog) and Sharkhog (stod + smad) and Khromjekhog [subgroup names in parantheses].

The suprasegmentals in these languages are various but the their origin may be only one system which is different from the well-known and widespread pattern of tonogenesis. In these languages, it is only Cone which has a pitch distinction in its phonology. On the other hand, mBrugchu has no suprasegmentals which function in the phonology but it has a phonetically clear realisation of "breathy voice."

The paper attempts to explain these differences with a new idea of tonogenesis: "registrogenesis," which originates from the difference of phonation without any relation to the phonological pitch height. In other words, the main phonetic characteristics of suprasegmentals belong to the phonation type. In this theory, the original pitch height would have been high for any kinds of initial simplexes as a default, as attested in many varieties of Amdo Tibetan, but there occurred many changes in initial complexes, which reflected to various phonation types (creaky, breathy, or tense, lax, etc.). Because the pitch and the phonation type are independent from each other, they two can co-occur in one language system, as in Wu of the Sinitic languages. In the Eastern Tibetic languages (ETL), these two features do not co-occur and the difference of phonation types can change their phonetic quality so that the pitch can be generated by losing various phonation realisations.

From the viewpoint of the development from the phonation to the pitch, the order of each ETL may be: The most primitive, i.e. phonation-like languages are mBrugchu (Ongsum + dGonpa); more phonation-like languages are dPalskyid (dPalskyid + Babzo) and Khodpokhog (gZitsakhog + nKhyungkyog); less phonation-like languages are Thewo (stod + smad), Sharkhog (stod + smad) and Khromjekhog; and more pitch-like languages are Cone (kLuchu + Nyinpa).