Acoustic analysis of the neutral tone in Mandarin

East Asian Languages such as Mandarin do have lexical tones in their phonological system. Pronounced in isolation, the fundamental frequency contours produced by these tones are relatively stable and their shapes well described phonetically. However, modifications can occur, not only in the well known case where two consecutive third tones are realized with a tone two tone three sequence, but in other contexts as well, producing either one of the three other tones available in the phonological system or a so called neutral tone. In this paper, specific acoustic characteristics of neutral tones resulting from sequences of three or more T3 tones are investigated. In particular, values of the fundamental frequency Fo glissando were evaluated and compared to a perception threshold. Other melodic features were considered as well.