tone. The historical connection is so regular that Punjabi is still written as if it had murmured consonants, and tone is not marked. The written consonants tell the reader which tone to use. Similarly, final fricatives or other consonants may phonetically affect the pitch of preceding vowels, and if they then weaken to and finally disappear completely, the difference in pitch, now a true difference in tone, carries on in their stead. This was the case with Chinese. Two of the three tones of Middle Chinese, the "rising" and the "departing" tones, arose as the Old Chinese final consonants and disappeared, while syllables that ended with neither of these consonants were interpreted as carrying the third tone, "even". Most varieties descending from Middle Chinese were further affected by a tone split in which each tone divided in two depending on whether the initial consonant was voiced. Vowels following a voiced consonant (depressor consonant) acquired a lower tone as the voicing lost its distinctiveness. The same changes affected many other languages in the same area, and at around the same time (AD 1000–1500). The tone split, for example, also occurred in Thai and Vietnamese. In general, voiced initial consonants lead to low tones while vowels after aspirated consonants acquire a high tone. When final consonants are lost, a glottal stop tends to leave a preceding vowel with a high or rising tone (although glottalized vowels tend to be low tone so if the glottal stop causes vowel glottalization, that will tend to leave behind a low vowel). A final fricative tends to leave a preceding vowel with a low or falling tone. Vowel phonation also frequently develops into tone, as can be seen in the case of Burmese. Stages of tonogenesis 1. The table below is the process of tonogenesis in White Hmong, described by Martha Ratliff. The tone values described in the table are from Christina Esposito. 2. The table below shows the Vietnamese tonogenesis. The tone values are taken from James Kirby. 3. The table below is the tonogenesis of Tai Dam (Black Tai). Displayed in the first row is the Proto-Southern Kra-Dai, as reconstructed by Norquest. Tone values are taken from Pittayaporn. 4. The table below shows the Chinese language tonogenesis. The tone values are listed below: SC= Standard Chinese (Putonghua) TSH= Taiwanese Sixian Hakka THH= Taiwanese Hailu Hakka XMM= Xiamen Min (Amoy) FZM= Fuzhou Min SZW= Suzhou