Functional Lateralization of Linguistic Tones: Acoustic Evidence from Norwegian

A group of five male right-hemisphere-damaged and five male left-hemisphere-damaged aphasics were recorded repeating a set of three phonemic tone-contrasted minimal pairs in Norwegian. A narrow-band spectrographic analysis revealed more impaired tone production (less phono-acoustic differentiation between phonemic pairs, and longer maximal productions) on the part of the left-hemisphere group than the right-hemisphere group, although the productions of the right-hemisphere group also seemed to be perturbed. A perceptual test of the patients' recorded productions by a native speaker revealed more lexical errors due to poor tone contrasts on the part of the left-hemisphere-damaged group. These results are discussed and compared to previous studies of linguistic tones in the neurological literature.