Table 2.
Masked auditory feedback (MAF) effects on syllable rate, disfluency duration, and vocal intensity.
| Participant ID | Speech diagnosis | Syllable rate |
Disfluency duration |
Vocal intensity |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Level change |
Variability change |
Level change |
Variability change |
Level change |
|||||||
| MAF effect | MAF release | MAF effect | MAF release | MAF effect | MAF release | MAF effect | MAF release | MAF effect | MAF release | ||
| P1 | AOS | 4.21*** | −1.53 | — | — | −3.34* | 0.71 | −11.30** | 0.53 | 5.37*** | −5.33*** |
| P2 | AOS | 4.04*** | −3.18* | — | — | −1.64 | 2.79* | −3.34 | 17.27*** | 5.40*** | −5.40*** |
| P3 | MIN | 2.80* | −2.31* | — | — | −2.64* | 1.7 | −8.22* | 3.34 | 5.40*** | −5.40*** |
| P4 | AOS | 2.69* | −0.74 | — | — | — | — | — | — | 5.40*** | −5.40*** |
| P5 | BORD | 2.58* | −1.37 | — | — | — | — | — | — | 5.40*** | −5.40*** |
| P6 | AOS | 2.50* | −2.85* | — | — | −2.33 | 2.39 | — | — | 4.58*** | −5.13*** |
| P7 | APP | 1.64 | 0.61 | — | — | −2.49* | 2.26 | −15.95*** | 13.75** | 5.40*** | −5.40*** |
| P8 a | AOS | — | — | — | — | −1.83 | 1.83 | −2.64 | 2.3 | 5.40*** | −5.40*** |
| P9 a | DYS | 0.5 | −0.01 | 2.59 | −5.08 | — | — | — | — | 5.40*** | −5.40*** |
| P10 | BORD | — | — | — | — | — | — | −0.64 | 0.06 | 5.40*** | −5.40*** |
Note. AOS = apraxia of speech; MIN =minimal speech impairment; BORD = borderline AOS; APP = aphasia with phonemic paraphasia; DYS = dysarthria. The effect of MAF on changed level and variability of syllable rate and disfluency is represented by nonparametric analyses (Wilcoxon [Z score] for level changes; Fligner-Killeen [X 2] for variability change). The effect of MAF represents comparison to the preceding baseline phase. Release from MAF indicates comparison of MAF measures to the following baseline condition. Negative values indicate that level or variability was reduced in comparison to the prior phase. Significance figures were adjusted for multiple comparisons using the Benjamini-Hochberg method (Benjamini & Yekutieli, 2001). Comparisons were only made for participants for whom a Kruskal–Wallis test indicated an overall effect of condition on a given factor. Em dashes indicate that tests among conditions were not completed because an overall effect was not found for that participant using the Kruskal-Wallis test.
P8 and P9 received the ACABA order (i.e., masking before altered feedback; A= NAF; B = AAF; C = MAF); all others received AAF before masking (ABACA order).
p < .05,
p < .01,
p < .001.