“In Chinese speech engineering, many projects use a conventional, syllable-based prosodic hierarchyas an underlying framework to process natural or synthesized speech. However, Chinese as a tonelanguage has its own way of expressing prosody, that is, through tonal interaction, especially tonesandhi. By utilizing the capacity of tone as a dual unit of pitch and timing, the present study proposesa tone-based, three-layer-four-level structure for Chinese prosody. The three layers are tone, toneprosody, and intonation, respectively composed of one level of pitch units, two levels of toneprosody units (basic and derived), and one level of intonation units. These four levels of units areused to replace syllable, prosodic word, phonological phrase, and intonational phrase in aconventional hierarchy. Tone prosody units are established based on sizes or types of tone sandhidomains, so when applied to the same clause uttered in Mandarin and Shanghai Wu Chinese, theyare timed differently and branched toward different directions at different levels, hence capable ofcapturing rhythmic and melodic patterns of the two distinctive types of Chinese. Overall, given itstheory-friendly design, the proposed structure may be used as a unifying framework in Chinesespeech engineering.”