Hengyang Xiang is spoken in Hengyang, Hunan Province of China, by an estimated 2.4 million speakers. Hengyang has six tones: a high-rising tone, a falling-rising tone, a low-rising tone, a low-level tone, a mid-level tone, and a low-mid tone. This study investigates the tonal system of Hengyang regarding pitch and voice quality, focusing on the two often-confusing rising tones in both isolated form and disyllabic words.

A map of Hengyang (colored) in Hunan province adapted from Wiki.

More details can be found here.