Title: Does Voicing Affect Patterns of Transfer in Nonnative Cluster Learning?
Authors: Hung-Shao Cheng and Adam Buchwald
Journal of Speech, Language, and Hearing Research (2021), 64, 2103–2120
https://doi.org/10.1044/2021_JSLHR-20-00240
Due to a technical error in the R script, the burst-to-burst duration measure for the stop-stop clusters only included data from 32 participants instead of 34 participants, which was reported in the article. While the overall findings of the article remain unchanged, the statistical values reported under the section of “Burst-to-Burst Duration” between pp. 2110–2111 as well as Figures 6 and 7 were reported incorrectly. The correct statistical values and Figures 6 and 7 are shown below.
Figure 6.
Change in burst-to-burst duration for the voiced training condition. The figure depicts overall burst-to-burst duration for each stimulus group from baseline to the first retention session (R1) and the second retention session (R2). The mean group duration was plotted against each individual's mean, and the error bars denote standard error. Separate lines connect baseline to R1 and to R2 to reflect our statistical comparison.
Figure 7.
Change in burst-to-burst duration for the voiceless training condition. The figure depicts overall burst-to-burst duration for each stimulus group from baseline to the first retention session (R1) and the second retention session (R2). The mean group duration was plotted against each individual's mean, and the error bars denote standard error. Separate lines connect baseline to R1 and to R2 to reflect our statistical comparison.
Figures 6 and 7 present the burst-to-burst duration data from the Voiced training (Figure 6) and Voiceless training (Figure 7) conditions respectively. As can be seen in these figures, there are intrinsic differences in these duration values on voiced clusters and voiceless clusters. In particular, burst-to-burst duration includes the release for the first stop, and that duration will be longer for the voiceless stops than for voiced stops. This leads the burst-to-burst duration to be systematically shorter for voiced clusters than voiceless clusters. In this section, we again consider the results and statistical outcomes relevant to the primary research questions of this paper and revisit this observation in the Discussion.
The best fitting model selected by AIC and BIC was the model that included random intercepts for participant and item, and we also included duration of the stressed vowel following the cluster as discussed above. The model revealed that stressed vowel duration was a significant predictor of burst-to-burst duration overall (β = 62.2, SE = 9.41, p < .0001). However, even taking that difference into account, the model revealed significant decreases in burst-to-burst duration from baseline to each retention session for the Trained items (R1: β = –10.92, SE = 1.59, p < .0001; R2: β = –10.74, SE = 1.58, p < .0001), Generalization items (R1: β = –11.06, SE = 1.60, p < .0001; R2: β = –9.12, SE = 1.59, p < .0001), and Transfer items (R1: β = –10.69, SE = 1.22, p < .0001; R2: β = –6.76, SE = 1.12, p < .0001) for the Voiced training condition. In addition, the model indicated that there was a significant difference in the magnitude of change at R2 (β = 3.97, SE = 1.94, p = .04), where the reduction in duration from baseline for the trained voiced clusters was greater than the reduction for transferred voiceless clusters. No other interaction terms were significant. Overall, these results indicate that participants who practiced voiced clusters produced those trained items with a closer coordination between the two consonants, and that this generalized to untrained nonwords with those clusters, and transferred to the untrained voiceless clusters.
For the Voiceless training condition, the model revealed that there was a significant decrease in burst-to-burst duration from baseline to each retention session for the Trained items (R1: β = –9.11, SE = 1.57, p < .0001; R2: β = −6.73, SE = 1.57, p < .0001), Generalization items (R1: β = –9.82, SE = 1.58, p < .0001; R2: β = −8.06, SE = 1.57, p < .0001), and Transfer items (R1: β = –7.6, SE = 1.13, p < .0001; R2: β = –4.87, SE = 1.12, p < .0001). The interaction between Session and Training was not significant. The results indicate that participants who practiced on voiceless clusters exhibited a decrease in burst-to-burst duration for trained items, and this generalized to untrained voiceless clusters, and transferred to voiced clusters. Thus, although there was a significant interaction between Session and Training for the Voiced training condition but not for the Voiceless training condition, the model did not reveal a significant interaction between Condition, Session and Training. This suggests that the amount of transfer is not asymmetric.