Table 2.
Summary of visual–acoustic biofeedback (VAB) studies in the context of speech sound disorder.
| Study | Year | N | Sex | Ages | Biofeedback type | Dose frequency | Total sessions | No. of teaching episodes | CII | Effect size a (range) |
|---|---|---|---|---|---|---|---|---|---|---|
| McAllister Byun et al. | 2016 | 9 | M-6; F-3 | 6;8–13;3 (M = 10;0) |
LPC | 30 min 2× per week | ~16 | 60 | 968 |
d2
−1.2 to 5.5 |
| Benway et al. | 2021 | 7 | M-3; F-4 | 9;5–15;8 (M = 12;3) |
LPC/ultrasound | 101 min/2× per week | 10 | 400 | 4000 |
d2
0–3.11 |
| McAllister Byun | 2017 | 7 | M-5; F-2 | 9;0–15;0 (M = 12;3) |
Traditional/LPC | 30 min 2× per week | 20 | 60 | 1200 |
d2
−5.3 to 9.87 |
| McAllister Byun & Hitchcock | 2012 | 11 | M-10; F-1 | 6;0–11;9 (M = 9;0) |
Traditional/LPC | 30 min 2× per week | 20 | 60 | 1200 |
d (group)
0.32 |
| Shuster et al. | 1995 | 2 | M-1; F-1 | 10;0–14;0 (M = 12;0) |
Traditional/spectrogram | (a) 50 min 2× per week (b) 60 min 1× per week |
24 | 150 175 |
(a) 3600 (b) 1400 |
NR |
| Hitchcock et al. | 2017 | 4 | M-3; F-1 | 8;8–13;0 (M = 9;10) |
LPC | 60 min 2× per week | 20 | 192 | 3840 |
d2
−1.63 to 18.92 |
| McAllister Byun & Campbell | 2016 | 11 | M-7; F-4 | 9;3–15;10 (M = 11;3) |
Traditional/LPC | 2× per week b | 20 | 60 | 1200 |
d2
−0.27 to 20.45 |
| McAllister Byun et al. | 2017 | 1 | F-1 | 13;0 | Traditional/LPC (staRt app) |
30 min 1× per week | 20 | 60 | 1200 | NR |
| Peterson et al. | 2022 | 4 | M-2; F-2 | 9;0–10;3 (M = 9;8) |
LPC (staRt app)/ telepractice |
2–3× per week b | 16 | 200 | 3200 |
d2
5.3–67.7 |
Note. CII = cumulative intervention intensity; M = male; F = female; LPC = linear predictive coding; NR = not reported.
a
Effect sizes were calculated for each individual by comparing /ɹ/ productions elicited in single-word probes administered during the true baseline phase (prior to the initiation of any treatment) and the posttreatment maintenance phase. Effect sizes were standardized using Busk and Serlin's (1992) d 2 statistic (Beeson & Robey, 2006), which pools SDs across baseline and maintenance periods to reduce the number of cases where effect size cannot be calculated due to zero variance at baseline.
b
Duration of session not reported.