Speaker: Runqi Tan (MIT)
Title: The role of perceptual contrast in tone inventory
Time: Monday, March 17th, 5pm - 6:30pm
Location: 32-D831
Abstract:
Theoretically, there are 2366 possible types of two- to five-tone inventories. However, a survey of 63 two- to five-tone languages reveals only 12 attested tone inventories. This discrepancy suggests that tone inventories are not formed through random selection of tones but are shaped by universal constraints. Yip (2001), based on a large-scale survey of tone languages, proposed universal rankings of markedness constraints: *RISE ≫ *FALL and *HIGH ≫ *LOW. Similarly, Chen (2000) proposed a markedness hierarchy: *RISE ≫ *HIGH ≫ *FALL ≫ *LOW. However, the markedness hierarchy alone does not account for the observed tone inventories.This study examines the role of perceptual contrast in shaping tone inventories within the framework of Dispersion Theory. By adding a set of MINDIST constraints, which evaluate the perceptual distinctiveness of tonal contrasts, to a set of markedness constraints that evaluate the articulatory efforts of tones, the new model successfully predicted 8 of the 12 attested tone inventories while avoiding over-generation. In addition, the model captures the following generalizations: (1) the mid-level tone does not co-occur with small contour tones and only co-occurs with large contour tones when both L and H are present in the inventory; (2) a tone system that only relies on pitch and slope for tonal contrasts can have no more than three contrastive levels per dimension; (3) it is possible for a language to have only contour tones without level tones. These findings suggest that perceptual contrast plays a crucial role in shaping tone inventories.