Discrimination of duration ratios in Estonian and English

Abstract

Estonian has been described as having a three‐way quantity distinction among disyllabic words based upon whether the ratio of the durations of syllable 1 to syllable 2 is approximately 2:3, 3:2, or 2:1. The present study was designed to examine the ability of listeners to discriminate among such duration ratios independent of other phonetic factors, such as fundamental frequency or segmental variations. Pairs of noise bursts (with 10 ms rise/fall times) whose durations were in the ratios of 1:2, 2:3, 3:2, and 2:1, were constructed. In half of these noise sequences the combined duration of noise 1 + noise 2 was 350 ms; in the other half the combined duration was 450 ms. Subjects were presented with two such sequences and were required to respond whether the duration ratios in the two sequences were the same or different. Equal numbers of sames and differents were randomly presented to 56 native listeners (and five trained phoneticians). Twenty‐eight listeners were native Estonians (whose data were collected in Tallinn, Estonia) and 28 listeners were native American English speakers (whose data collected in Columbus, OH). Obtained results show that both groups of listeners clearly recognized only two contrastive patterns: 1:2 and 2:3 vs 3:2 and 2:1. In addition, overall sequence duration had a significant effect upon duration ratio discriminations. These results will be discussed in light of possible language group difference, phonetic training differences, and in terms of psychoacoustic limits on the contrastive use of duration in languages.