Fig 1.
Illustration of the delayed auditory feedback (DAF) experiment.
Fig 2.
Illustration of the pitch-perturbed auditory feedback (PAF) experiment.
Table 1.
Results of a linear mixed effects model for speech rate.
Table 2.
Results of a linear mixed effects model for voice intensity.
Table 3.
Results of a linear mixed effects model for voice pitch.
Fig 3.
Effect of delayed auditory feedback on speech.
a) Voice intensity, b) Voice pitch and c) Speech rate averaged across trials and participants for simultaneous (0ms) and delayed (200ms) auditory feedback when visual feedback is present (red) and absent (blue). Error bars indicate standard error of the mean across trials. d) The effect of trial order on speech rate for simultaneous (green) and 200ms delayed (purple) auditory feedback. Shaded regions indicate 95% confidence intervals.
Fig 4.
Individual variability in susceptibility to delayed auditory feedback.
a) Comparison of speech rates during simultaneous (green bars) and 200ms delayed (purple bars) auditory feedback in two different participants. b) Random slope values from the LME model which represent the effect of auditory feedback delay on speech rate for different participants. Red arrows indicate the participants that were shown in panel a.
Fig 5.
Vocal responses to F0 perturbation.
a) Pitch contours during the phonation of the vowel /a/ with no perturbation, 100-cent and 200-cent perturbation in the upward and downward directions averaged across participants. Shaded regions indicate standard error of the mean across participants. b) Pitch contours of compensatory (opposing) vocal responses during the phonation of the vowel /a/ with 100-cent and 200-cent perturbation in the upward and downward directions averaged across participants. Shaded regions indicate standard error of the mean across participants. T1: 0 to 200, T2: 200 to 500 and T3: 500 to 800 milliseconds indicate different time periods with respect to the perturbation onset. Black dashed rectangle highlights time period T2 within which the maximum vocal responses are determined for the LME analysis c) Pitch contours of following vocal responses averaged across participants with shaded regions indicating standard error of the mean.
Table 4.
Percentage of different vocal response types for different F0 perturbation conditions.
Table 5.
Results of a linear mixed effects model for the peak amplitude of the compensatory response.
Fig 6.
Effects of trial order on the peak amplitude of the compensatory response.
Change in peak amplitude with the progression of trials for 100-cent (yellow) and 200-cent (brown) perturbation. Shaded regions indicate 95% confidence intervals.
Table 6.
Results of a linear mixed effects model for the peak amplitude of the compensatory responses to all F0 perturbations.
Fig 7.
Individual variability in susceptibility to F0 perturbed auditory feedback.
a) Comparison of peak amplitudes during non-perturbed (green bars) and perturbed (purple bars) auditory feedback in two different participants. b) Random slope values from the LME model which represent the effect of perturbation on the peak amplitude for different participants. Red arrows indicate the participants that were shown in panel a.
Fig 8.
Correlation between DAF and PAF susceptibilities.
Gray circles represent individual participants (P1–P40) and their susceptibility to DAF and PAF. The gray fitted line illustrates the lack of a significant correlation between susceptibilities in the two tasks. Dashed lines mark the 75th percentile thresholds, with participants above these thresholds classified as highly susceptible to DAF (blue) and PAF (green). The Venn diagram highlights that, of the 10 highly susceptible participants in each task, only three were highly susceptible to both DAF and PAF (circled in red).