Music & Language Studies

BLUMSTEIN, Sheila, and William E. Cooper. “Hemispheric Processing of Intonation Contours.” Cortex 10/2 (1974): 146-158.

Two perceptual experiments were conducted, exploiting dichotic listening techniques, to examine hemispheric lateralization for processing of intonation contours. Stimuli in the first experiment used filtered speech sounds, such that the phonetic information was veiled, but the intonational information remained. In the second, nonsense syllables were used, to ascertain whether recognizable phonetic information would alter the right-hemisphere superiority found in the first. It was concluded that there is a significant left-ear (right-hemisphere) advantage for attending to prosodic features of language. Comparison was made to findings by Van Lancker and Fromkin in 1972, which indicated that local pitch contours in Thai (a tone language) were lateralized to the left-hemisphere.

A comparison of intonation and pitch contours is relevant here, since both are similar acoustically, both serve a linguistic function, and yet, they demonstrate different ear advantages. …Although both types of contours serve a linguistic function, the nature of their role in the linguistic message is very different. Pitch contours minimally distinguish individual words in language in a manner similar to consonant or vowel phonemes… Intonation contours, on the other hand, minimally distinguish different sentence types. (156)

Mention is also made of the development of Melodic Intonation Therapy for aphasia (see Albert et al 1973, above), which generated marked improvement in the expressive ability of patients by encoding linguistic phrases with simple melodic patterns.

It may be that the use of these contours directly involves the non-dominant hemisphere in either the producing language or in enhancing its production by the damaged dominant hemisphere. (156)

Finally, the authors speculate:

[N]ormal language perception may involve the simultaneous analysis of the linguistic input in both hemispheres — with the analysis of the phonetic and semantic components of language conducted primarily in the left hemisphere and the analysis of intonational and perhaps other components of the speech signal conducted primarily in the right hemisphere. (156)

From this research, it seems apparent that speech is a complex stimuli, and that the brain accordingly processes it in complex ways. There are different aspects of the speech signal, however, which may be isolable (at least in experimental contexts) and dissociable in pathological contexts.