Iambic-Trochaic Law Effects among Native Speakers of Spanish and English

Megan Crowhurst

doi:10.5334/labphon.42

Abstract

The Iambic-Trochaic Law (Bolton, 1894; Hayes, 1995; Woodrow, 1909) asserts that listeners associate greater intensity with group beginnings (a loud-first preference) and greater duration with group endings (a long-last preference). Hayes (1987; 1995) posits a natural connection between the prominences referred to in the ITL and the locations of stressed syllables in feet. However, not all lengthening in final positions originates with stressed syllables, and greater duration may also be associated with stress in nonfinal (trochaic) positions. The research described here challenged the notion that presumptive long-last effects necessarily reflect stress-related duration patterns, and investigated the general hypothesis that the robustness of long-last effects should vary depending on the strength of the association between final positions and increased duration, whatever its source. Two ITL studies were conducted in which native speakers of Spanish and of English grouped streams of rhythmically alternating syllables in which vowel intensity and/or duration levels were varied. These languages were chosen because while they are prosodically similar, increased duration on constituent-final syllables is both more common and more salient in English than Spanish. Outcomes revealed robust loud-first effects in both language groups. Long-last effects were significantly weaker in the Spanish group when vowel duration was varied singly. However, long-last effects were present and comparable in both language groups when intensity and duration were covaried. Intensity was a more robust predictor of responses than duration. A primary conclusion was that whether or not humans’ rhythmic grouping preferences have an innate component, duration-based grouping preferences, at least, and the magnitude of intensity-based effects are shaped by listeners’ backgrounds.

Highlights

2.1 The rhythmic grouping literatureThe most widely cited historical antecedents for modern ITL studies are Bolton (1894) and Woodrow (1909), who tested the preferences of adult American English speakers who were asked to group patterned sequences of tones or clicks in which intensity and duration were systematically varied
The proportion of baga responses was generally higher when ga was longer than ba, compared to the control condition, and the proportion of baga responses was lower when ba was longer than ga at MODs 3 and 4, consistent with the Long-Last Principle in (1)
More granular predictions were made by the Incremental Loud-Soft and Intensity Attenuation hypotheses in (2a) and (2b)

Summary

Introduction

The most widely cited historical antecedents for modern ITL studies are Bolton (1894) and Woodrow (1909), who tested the preferences of adult American English speakers who were asked to group patterned sequences of tones or clicks in which intensity and duration were systematically varied. In addition to studying intensity and duration varied singly, Bolton (1894) investigated the effect of varying them orthogonally He found that when listeners segmented sequences that alternated a long soft tone with a short loud one, listeners preferred the grouping in which the loud tone came first and the long came last.

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Conclusion