TABLE 3.
Relevant data from included studies.
| Author(s) | Domaina | Features | n ASD (M), M:F ratio | ASD age M ± SD (range) | Controlsb | NVIQ M ± SD (range)c | Exp. lang M ± SD (range)d | Methode | Testf | Resultsg |
|---|---|---|---|---|---|---|---|---|---|---|
|
| ||||||||||
| Adams (1998) | S/NS | Accuracy | 4 (3), 3:1 | 9.0 ± 2.3 (6.3–11.3) | TD | LIPS (92.75 ± 10.5) | - | P | KSPT | TD > ASD on oral movements, complex productions, and total score; ASD = TD on simple productions |
| Akin-Bulbul and Ozdemir (2022) | S/NS | Accuracy | 30 (22), 2.8:1 | 2.7 ± 0.3 (2.3–3) | TD, DD | BSID-III Cognitive m = 24 | - | P | - | TD > ASD on meaningful and nonmeaningful vocal imitation |
| Amato and Slavin (1998) | S/NS/F | Accuracy, feeding difficulty | 20 (16), 4:1 | (2.5–4.0) | - | - | V and NV | P | OME | Verbal and nonverbal groups had reduced oromotor functioning. V > NV on overall score, eating behaviors, voluntary nonverbal oral ability, and pre-speech/speech behavior; V = NV on musculoskeletal anatomy and basic oral motor functions |
| Arutiunian et al. (2022) | S | Accuracy | 71 | 9.6 ± 1.4 (7–11.1) | TD | 83.1 ± 20.5 (40–125) | Various | P | - | TD > ASD on nonword repetition, TD = ASD on word repetition |
| Ashley et al. (2020) | F | Feeding difficulty | 19 (15), 3.8:1 | (1.3–3.0) | TD, HR, non-TD | MSEL-VR (30.9 ± 10.9) | MSEL-EL 25.9 ± 8.1 | Q | BPFAS | ASD = TD on oral motor skills for eating |
| Belmonte et al. (2013) | S/NS | Accuracy | 31 (25), 4.2:1 | 3.4 ± 0.8 (1.8–5.4) | - | - | Various | P | CDOMA | 35% of ASD group had an oral motor impairment associated with an EL/RL disparity (EL < RL). Oral motor skills correlated with pre-intervention RL and EL and with learning rates. Oral motor skills varied independently of GM and FM |
| Biller and Johnson (2019) | S | Accuracy, voicing | 5 (4), 4:1 | 5.3 ± 1.3 (3.6–6.9) | - | MSEL-VR AE 1:8–2:7 | MSEL AE 0.9 ± 0.2 | P | VMPAC | MV autistic children below age level on oromotor control and number of speech sounds/syllables produced imitatively or spontaneously |
| Biller and Johnson (2020) | S | Accuracy, voicing | 1 (1) | 3.3 | - | MSEL-NV AE 2:1 | MSEL-EL AE 1.8 | P | VMPAC | Oromotor control skills in 5th percentile |
| Biller et al. (2022) | S | Inventory, voicing | 1 (1) | 4.9 | - | MSEL-VR 2:0 | Exp. vocab 25 words | P | VMPAC | Limited sound repertoire |
| Bodison (2015) | NS | Accuracy | 32 (25), 3.6:1 | 7.5 ± 1.4 (5–8.9) | - | - | - | P | SIPT | Reduced imitative oral praxis |
| Boorom (2018) | S | Accuracy | 11 (11) | 4.9 ± 0.3 (4.3–5.4) | - | - | TOPEL DV raw 24.1 ± 17.3 | P | CTOPP-2 | Below average group mean for nonword repetition |
| Brisson et al. (2012) | F | Motor anticipation | 13 (13) | 0.3 ± 0.1 (0.3–0.5) | TD | 8/13 subjects IQ < 75 | - | P | - | TD > ASD on anticipatory mouth opening in response to an approaching spoon |
| Broome et al. (2021) | S | Accuracy, inventory | 22 (20), 10:1 | 3.9 ± 1.2 (2–5.3) | - | WPPSI-III 99 ± 20.7 | PLS-4 EC 65.6 ± 14.2 (50–85) | P | POP | Cluster analysis identified three subgroups: high language/high speech, low EL/low speech/high RL, and low language/low speech |
| Broome et al. (2022) | S | Inventory | 23 (21), 10.5:1 | 4.4 ± 1.3 (2–7.2) | - | WPPSI-III 99 ± 20.7 | PLS-4 EC 65.6 ± 14.2 (50–85) | P | POP, SWPT | Varied speech development trajectories by subgroup: high language/high speech and low EL/low speech/high RL remained stable; low language/low speech was variable |
| Cattaneo et al. (2007) | F | Muscle activity | 8 (7), 7:1 | 6.2 (5.1–9.0) | TD | WISC-R (98 ± 12.4) | - | I | - | TD > ASD on mylohyoid activity while observing a person eat and while reaching for/grasping food |
| Chenausky and Schlaug (2018) | S | Accuracy, inventory | 30 (25), 5:1 | 6.4 (3.4–9.7) | - | - | EV < 20 words | P | - | Reduced % syllables approximately correct at baseline |
| Chenausky and Tager-Flusberg (2017) | S | VOT | 11 (7), 1.8:1 | 2.2 ± 0.6 (1.5–3) | TD, HR− | - | Age 3 MSEL EL 53.6 ± 8.6 | P/I | - | ASD = HR− = LRC on VOT mean and standard deviation. ASD significantly less likely to produce acoustically distinct VOT for /b/ and /p/ at 36 months, but not at 18 or 24 months |
| Chenausky et al. (2016) | S | Accuracy, inventory | 30 (27), 9:1 | 1.5 ± 0.5 (1–2) | - | MSEL-MA (21.4 ± 9.2) (n = 14) | EV < 20 words | P/I | KSPT | Reduced syllables approximated, vowels correct, and consonants correct at baseline |
| Chenausky, Kernbach, et al. (2017) | S | Accuracy, inventory | 30 (25), 5:1 | 6.3 ± 1.6 (3.4–9.7) | - | MSEL-VR (27.9 ± 9.7) | MSEL EL 11.2 ± 2.4 (6–19) | P | - | White matter integrity accounted for significant variance in % syllable-initial consonants correct, % responses, and % syllable insertions |
| Chenausky Nelson, and Tager-Flusberg (2017) | S | Inventory | 10 (7), 2.3:1 | 6.3 (3.4–9.7) | TD, HR− | - | Age 2 MSEL EL 48.0 ± 9.2 | P | - | Vocalization rate predicted # different consonants for non-autistic, but not autistic, children at 12 months and for both groups at 18 and 24 months. EL predicted # different consonants for only the non-autistic children at 18 and 24 months. Mean # different consonants at 12, 18, and 24 months was not significantly different between groups |
| Chenausky, Norton, and Schlaug (2017) | S/NS | Accuracy, inventory | 4 (4) | 5 ± 1.2 (4.1–6.6) | - | MSEL-VR (26.8 ± 13.9) | MSEL EL raw 13.3 ± 4.4 | P | KSPT | V > MV on oral movements and simple phoneme/syllables |
| Chenausky et al. (2018) | S | Accuracy, inventory | 38 (31), 4.4:1 | 6.4 ± 1.6 (3.4–10.7) | - | MSEL-VR (30.1 ± 9.6) | MSEL EL 11.1 ± 2.7 | I | - | Reduced % syllables approximately correct at baseline. Baseline phonetic inventory significantly predicted change in % syllables approximately correct, while nonverbal IQ, baseline expressive language, and age did not |
| Chenausky et al. (2019) | S/NS | Accuracy, rate, coordination, consistency, resonance, voicing | 54 (41), 3.2:1 | 6.5 ± 1.7 (3.4–10.7) | - | LIPS-3 30–115 (67.4 ± 19.5) | NDW 46.3 ± 57.1 | P | - | 24% of sample exhibited severely disordered speech including >4 signs of CAS, 30% had speech abnormalities inconsistent with CAS, and 24% produced too little speech for analysis. NS oromotor ability was not predictive of EL. Speech imitation predicted # different words in the sCAS and insufficient speech groups |
| Chenausky et al. (2020) | S | Accuracy, rate, coordination, consistency, resonance, voicing | 27 (24), 8:1 | 6.6 ± 1.4 (4–9.7) | CAS | MSEL-VR raw (29.6 ± 9.0) | MSEL EL raw 11.2 ± 1.7 (8–14) | P | GFTA-2 | MV autistic children with CAS exhibited significantly slower rate and more vowel errors, syllable segmentation, groping, difficulty with coarticulation, and additions compared to a verbal CAS group, although fewer consonant distortions |
| Chenausky et al. (2021) | S | Accuracy, rate, coordination, inventory, consistency, resonance, formants | 38 (33), 6.6:1 | 6.8 ± 1.7 (5–10.7) | - | MSEL-VR 30.3 ± 9.8 | MSEL EL raw 11.3 ± 2.7 (6–19) | P | KSPT | A cluster defined by perceptual within-token variability demonstrated more within- and between-token variability and less centralized vowel space than the low variability group and TD |
| Chenausky, Norton, et al. (2022) | S | Accuracy, inventory | 14 (11), 3.7:1 | 10 ± 3.9 (4.3–18.8) | - | LIPS-3 69.1 ± 8.5 | EV < 20 words | P | KSPT | Low % syllables, consonants, and vowels correct; low KSPT scores; small phonetic inventory |
| Cleland et al. (2010) | S | Accuracy | 69 | 9.5 ± 2.2 (5.0–13.0) | - | RPM (103.0 ± 15.0) | CELF-3 EL 84.1 ± 20.2 | P | GFTA-2 | 12% of sample below average on GFTA, although 33% in the normal range presented with errors. Non-developmental errors observed in both groups |
| Dalton et al. (2017) | S/NS | Accuracy | 10 (6), 1.5:1 | 4.8 ± 0.5 (3–5.5) | TD, sCAS | MSEL-VR AE 4.8 ± 1.3 | MLU > 3.0 | P | VMPAC | ASD = TD = sCAS on nonverbal oral, verbal motor, and concurrent verbal motor imitation. NS oral imitation and verbal motor imitation were correlated with joint attention only in ASD group |
| Demartini et al. (2021) | F | Feeding difficulty | 106 (77), 2.7:1 | 33.2 ± 12.9 (17–67) | TD | WAIS-IV ≥ 70 | ADOS communication 4.7 ± 2.0 | Q | SWEAA | TD > ASD on motor control for eating |
| Demopoulos and Lewine (2016) | S | Accuracy | 60 (48), 4:1 | 10.8 ± 3.4 (5.5–18.5) | TD | WISC-IV FSIQ 46–136 (81.7 ± 22.0) | CELF-4 EL 75.5 ± 26.6 (45–128) | P | GFTA-2 | ASD = TD on GFTA |
| Deshmukh (2012) | S/NS | Accuracy, rate, consistency | 12 (12) | 6.5 ± 1.9 (4–10.3) | TD, MSD | - | EVT 100.0 ± 14.8 | P | DEAP, GFTA-2, OSMSE-3 | ASD group had normal oral structure/function. 15% of the ASD group below the normal range on the GFTA. ASD = TD on rate and consistency |
| Diehl and Paul (2013) | S | Duration | 24 (16), 2:1 | 12.3 ± 2.3 (8.0–16.0) | TD, LmD | WASI/D AS (103.61 ± 17.14) | CELF-IV 100.5 ± 16.2 | I | PEPS-C | ASD > TD on utterance length when expressing dislike, asking questions, and making statements. ASD = TD when expressing like and when using stress to indicate focus |
| Ehlen et al. (2020) | S | Rate | 32 (18), 1.3:1 | 37.1 ± 10.7 | TD | Incl. criteria >85 | - | I | - | ASD = TD on word duration |
| Espanola Aguirre and Gutierrez (2019) | S/NS | Accuracy | 30 (22), 2.8:1 | 3.6 ± 1.0 (1.3–4.0) | TD | MSEL composite 56.6 ± 11.3 | MCDI # of words 155.7 ± 150.1 | P | MVIA | ASD = TD on vocal and facial imitation |
| Franich et al. (2020) | S | Coordination | 10 (9), 9:1 | (22–31) | TD | TONI-4 (102.33 ± 9.56) | - | I | - | TD > ASD on timing phrases along with a metronome; ASD had longer time interval between two consecutive repetitions of first word in target phrase |
| Gabig (2008) | S | Accuracy, intelligibility | 15 (13), 6.5:1 | 6.5 ± 0.7 (5–7.9) | TD | DAS 95 ± 10.6 | LUL 5.1 ± 2.1 | P | TOLD-P:3 | 53% of ASD group below average on an articulation task |
| Gal et al. (2022) | F | Feeding difficulty | 105 (87), 4.8:1 | 3.4 ± 1.3 (3–7.9) | TD | - | - | Q | AEQ | TD > ASD on chewing and swallowing function |
| Gemsbacher et al. (2008) | NS | Accuracy | 115 (92), 1.3:1 | 7.9 ± 3.7 (2.3–18.9) | TD | - | Various | P/Q | KSPT | TD > ASD on parent reports of NS oromotor skills; parent reports distinguished autistic children with minimally, moderately, and highly fluent speech. Reports of oromotor and manual motor skills were correlated. Home videos corroborated parent reports for 97% of subjects. During direct assessment, minimally and highly fluent autistic children were significantly distinguished on most NS oral motor tasks |
| Gladfelter and Goffman (2018) | S | Accuracy, consistency | 12 (9), 3:1 | 7.8 ± 1.9 (4.6–11.3) | TD | TONI-4 (96.6 ± 6.54) | EVT 95.8 ± 7.6 (79–112) | P/I | - | ASD = TD on oral mechanism exam. ASD = TD on increase in phonetic accuracy during word learning. Although not more stable at baseline, ASD > TD on gains in stability from pre- to post-test |
| Grossman et al. (2010) | S | Duration | 16 | 12.3 ± 2.3 (7.5–17.0) | TD | KBIT-2 (109.6 ± 19.1) | - | I | - | ASD > TD on length of first- and last-syllable stress items |
| Heller Murray et al. (2022) | S | Brain activity | 15 (12), 4:1 | 16.7 ± 2.3 (13.8–21.1) | TD | LIPS-3111.9 ± 26.3 | NDW/minute 10.3 ± 4.4 (4.9–20.6) | I | - | ASD = TD on average speech activation and inter-subject variability in speech activation; ASD > TD on intra-subject neural variability. Intra-subject variability correlated with autism severity but not number of words |
| Hubbard and Trauner (2007) | S | Duration | 18 (6), 2:1 | 14.5 (6–21) | TD | - | - | I | - | Non-autistic children and children with AS had longer syllable durations during sad compared to happy and angry utterances, children with autism did not |
| Karlsson et al. (2013) | F | Feeding difficulty | 57 (38), 2:1 | 18.7 ± 2.9 (15–25) | TD | WISC/WAIS > 70 | - | Q | SWEAA | ASD = TD on motor control for eating |
| Kasthurirathne et al. (2020) | S | Resonance | 11 (9), 4.5:1 | 15.8 ± 1 (14–17) | TD | - | Verbally fluent | I | - | ASD > TD on nasalance |
| Kim (2014) | S | Accuracy | 2 (2) | 8.3 ± 1.5 (7.2–9.3) | - | - | - | P | - | Reduced phoneme accuracy at baseline |
| Kim and Seung (2015) | S/NS | Accuracy, inventory | 1 (1) | 11 | - | - | EVT-2 AE 3.3 | P | GFTA-2, KSPT | Normal NS oromotor skills except reduced range of lip movement. Accurately produced all individual vowels, consonants, syllable types, repetitive syllables, and simple monosyllabic words. Age equivalent of 2 years on the GFTA; atypical errors and inconsistent error patterns within and across sessions |
| Kissine and Geelhand (2019) | S | Consistency, duration, formants | 38 (26), 2.2:1 | 28.1 ± 11.5 | TD | WAIS-4 FSIQ (112.0 ± 25.8) | - | I | - | TD > ASD on F1–F3 dispersion, indicating increased articulatory stability in the ASD group. ASD > TD on syllable duration |
| Kissine et al. (2021) | S | Consistency, formants | 20 (20) | 31.6 ± 10.7 (17–52) | TD | WAIS-IV 112.06 ± 22.8 | - | I | - | ASD > TD on articulatory stability; ASD group’s non-native vowel production was less accurate and more influenced by native vowels than TD group |
| Kjelgaard and Tager-Flusberg (2001) | S | Accuracy | 89 (80), 8.9:1 | 7.3 ± 2.4 (4–13.9) | - | DAS (90.1 ± 19.6) | CELF-EL 74.86 ± 17.63; EVT 84.89 ± 17.51 | P | GFTA | Average GFTA scores for normal, borderline, and impaired language subgroups, although the impaired group scores were significantly lower than both other groups |
| Koegel et al. (1998) | S | Accuracy, intelligibility | 5 (4), 4:1 | 5.5 ± 1.4 (3.7–7.5) | - | - | Various | P | AAPS | Intelligibility ratings ranged from “mostly not intelligible” to “sometimes intelligible” |
| Kothare et al. (2021) | S | Speed | 22 (12), 1.2:1 | 11.4 ± 2.5 (8–18) | - | WISC-FSIQ 102.95 ± 19.79 | CELF-5 EL 100.1 ± 20.5 (59–131) | I | - | Jaw speed/acceleration correlated with dominant hand speed |
| Landa et al. (2013) | S | Inventory | 54 (44), 4.4:1 | (0.5–3.5) | TD, HR− | MSEL-C 85.3 ± 19.0 | - | P | - | TD > early-ASD group (first clinical impression by 14 months) on consonant inventory at 14, 18, and 24 months. TD > late-ASD group on consonant inventory at 14 and 24 months. Early ASD = late ASD on consonant inventory |
| Lau et al. (2022) | S | Rhythm | 57 (48), 5.3:1 | 16.6 ± 8 (6–35) | TD | WASI/WAIS/WISC-IV 106.15 ± 12.97 | - | I | - | TD > ASD on speech rhythm measures |
| Leader et al. (2020) | F | Feeding difficulty | 136 (98), 2.6:1 | 8.4 ± 4.1 | - | - | - | Q | STEP-CHILD | 60% of sample reported to have chewing problems |
| Lundin Remnélius et al. (2022) | F | Feeding difficulty | 28 (13), 0.9:1 | 20.3 ± 4.4 (15–31) | TD, LrnD, ID | 92.86 ± 21.22 | - | Q | SWEAA | Motor control for eating correlated with internalizing conditions but not autistic traits |
| Lyakso et al. (2016) | S | Duration, formants | 25 | (5–14) | TD | - | - | I | - | ASD ≠ TD on F3 values during emotional speech, F2–F1 values for /a/ and /u/, and F3–F2 values for /i/. Autistic children who had developmental reversals at age 1.5–3 years ≠ those at developmental risk from birth on formant measures |
| Lyakso et al. (2017) | S | Duration, intelligibility, formants | 30 | (5–14) | TD | MA 4:0–7:0 | - | P/I | - | TD > ASD on word intelligibility. Listeners falsely identified male autistic subjects as female more often than TD children and tended to underestimate the age of the autistic children. Autistic children with a developmental reversal at age 1.5–3 years ≠ those at developmental risk from birth on vowel duration |
| Mahler (2012) | S/NS | Accuracy, rate, consistency | 7 (7) | 7.4 ± 1.7 (5.1–10.3) | TD | - | EVT 105.3 | P | DEAP, GFTA-2, OSMSE-3 | TD > ASD on DDK accuracy, consistency. TD = ASD on DDK rate. ASD in normal range on GFTA and OSMSE Structure/Function. 86% failed OSMSE DDK task |
| Mandelbaum et al. (2006) | S/NS | Accuracy, rate, neuro exam | 116 (93), 4:1 | 8.9 ± 1.6 (7–10) | ID, DLD | Various | - | P | - | Non-ASD/low-IQ > ASD/low-IQ on oromotor tasks. ASD/high-IQ > ASD/low-IQ on timed and untimed oromotor tasks. Per neurological exam, ASD/low-IQ > DLD, ASD/low-IQ > ASD/ high-IQ, and non-ASD/low-IQ > ASD/high-IQ on ratings of oromotor apraxia |
| Manfredonia et al. (2019) | NS | Facial expression | 144 (112), 3.5:1 | 14.6 ± 7.8 (6–54) | TD | KBIT-2 99.2 ± 19.6 | - | I | - | TD > ASD on upturned lip comer during happy emotional expression; activations of lip and jaw correlated with social skills |
| McCann et al. (2007) | S | Accuracy | 31 (25), 4.2:1 | 9.8 (6–13) | TD | RPM 96.4 ± 15.9 | CELF-3 EL 90% below normal limits | P | GFTA-2 | Within ASD group, 84% scored within the normal range, 10% had a mild impairment and 6% had a more significant impairment on GFTA |
| McCleery et al. (2006) | S | Accuracy | 14 (12), 6:1 | 3.3 (2.1–6.9) | TD | BSID MA (1:6) | MCDI NDW 7 (0–26) | P | - | ASD = TD on patterns of phoneme acquisition and production |
| McDaniel et al. (2018) | NS/F | Accuracy | 65 (54), 4.9:1 | 3.6 ± 0.6 (2.7–4.7) | - | MSELDR 36 ± 15 | MCDI NDW 17 ± 25 (0–117) | P | OME | Reduced eating and NS oromotor skills. Imitative and nonimitative oral motor performance was not significantly correlated with receptive–expressive vocabulary discrepancy |
| McKeever et al. (2022) | S | Accuracy, rate, consistency | 8 (6), 3:1 | 10.1 ± 2.1 (6.3–12.5) | TD | LIPS 89.71 ± 11.37 | - | I | - | ASD = TD on max rate of syllable production, accuracy of single syllable sequences, and articulatory stability. ASD group was more likely to have different tongue shapes for fast and slow rates |
| Nadig and Shaw (2011) | S | Rate | 15 (13), 6.5:1 | 10.8 ± 1.5 (8.4–14.4) | TD | WASI PIQ 81–126 (105 ± 15) | - | P/I | - | ASD = TD on speech rate, perceptually and acoustically |
| Nakaoka et al. (2022) | F | Feeding difficulty | 294 (229), 3.5:1 | 10 ± 4 (3–18) | - | - | SCQ 12.1 ± 7.3 | Q | ASD-MBQ | Reduced score on oral motor function for eating. Oral motor function correlated with social skills and sensory profile |
| Narzisi et al. (2013) | S | Accuracy | 22 (22) | 9.8 ± 3.7 (5–16) | TD | WISC-III PIQ 72–141 (103.4 ± 16.3) | NEPSY-II Language scores similar to controls | P | NEPSY-II | TD > ASD on production of articulatory sequences and tongue twisters |
| Noterdaeme (2002) | S/NS | Accuracy | 11 (8), 2.7:1 | 9.8 ± 2.3 | TD, ELD, RLD | KABC 103 ± 14 | HTLF IS 38 ± 15 | P | - | Per neurological exam, ASD = TD on oral motor function |
| Ochi et al. (2019) | S | Rate | 62 (62) | 26.9 ± 7 | TD | WAIS-III FSIQ 106.4 ± 14.3 | - | I | - | ASD = TD on speech rate and speech rate variance |
| Pang et al. (2016) | S/NS | Brain activity | 21 (17), 4.3:1 | 11.4 ± 3.2 (6–17.6) | TD | WASI NVIQ 96.4 ± 18.1 | OWLSII-OE 88.6 ± 24.4 | I | - | During nonspeech task, ASD > TD on magnitude and delayed latency in motor control areas and magnitude in an executive control area. During phoneme production, ASD > TD on latency delays in frontal and temporal language processing areas. During oromotor sequencing, ASD > TD on magnitude and delayed latency in a sensory integration area |
| Parish-Morris et al. (2018) | S | Consistency, diversity | 17 (15), 7.5:1 | 26.9 ± 7.3 | TD | WASI-II FSIQ 102.1 ± 19.8 | - | I | - | TD > ASD on mouth movement diversity |
| Parmeggiani et al. (2019) | F | Sucking reflex | 105 (82), 3.6:1 | 1.1 ± 0.8 (0.3–4) | - | Various | - | R | - | Absent sucking reflex in 16.2% of ASD sample |
| Pascolo and Cattarinussi (2012) | F | Muscle activity | 7 (7) | 7.3 ± 1.8 | TD | WISC-R > 70 | - | I | - | ASD = TD on mylohyoid activity and timing of initiation of mouth opening when bringing food to mouth |
| Patel et al. (2020) | S | Rate | 55 (45), 1.2:1 | 16.6 ± 6.6 (6.5–35.1) | TD | WISC-4 FSIQ 104.22 ± 12.03 | - | P/I | - | TD > ASD on speech rate instrumentally, but not perceptually |
| Paul et al. (2008) | S | Duration | 46 (43), 14.3:1 | 13.2 ± 4.4 (7.3–28.6) | TD | WISC-3 PIQ 95.0 ± 20.5 | CELF-III EL 99.7 ± 21.5 | I | T-TRIP | No differences in syllable duration among uncombined ASD groups (HFA, AS, PDD-NOS). For the combined ASD group, ASD > TD on difference between duration of stressed and unstressed syllables |
| Peter et al. (2019) | S | Accuracy | 2 (1), 1:1 | 6.7 ± 3 (4.6–8.8) | TD | RIAS-NII (84) | “Severely delayed” | P | GFTA-2 | Two siblings with dx of ASD and CAS demonstrated reduced articulatory accuracy, vowel errors, inconsistent errors, and reduced DDK rates. Shared genetic variants contributing to ASD and CAS were proposed |
| Peterson et al. (2016) | F | Feeding difficulty | 6 (6) | (4–6) | - | - | - | P | - | Reduced ability to clear mouth of food within 30 s for most of ASD sample |
| Peterson et al. (2019) | F | Feeding difficulty | 6 (6) | (3–5) | - | - | - | P | - | Reduced ability to clear mouth of food within 30 s |
| Petinou (2021) | S | Accuracy, inventory, intelligibility | 1 (1) | 4 | - | - | - | P | - | Reduced phonetic inventory, percent consonants correct, words correct, and intelligibility |
| Plumb and Wether by (2013) | S | Accuracy | 50 (43), 6.1:1 | 21.3 ± 1.9 (18–26.9) | TD, DD | MSEL NVDQ 76.0 ± 25.8 | - | P | - | TD > ASD on proportion of vocalizations containing at least a vowel. ASD > TD on proportion of atypical and distress vocalizations. Within ASD group, vocalizations containing a vowel were correlated with developmental levels, and communicative vocalizations uniquely predicted age 3 EL |
| Rainsdon (2018) | S | Accuracy | 3 (2), 2:1 | 4 ± 0.2 (3.8–4.2) | - | - | SPELT-P2 54–69 | P | GFTA-3 | All participants in the below-average range on the GFTA |
| Rogers et al. (1996) | NS | Accuracy | 17 (15), 7.5:1 | 2.9 ± 0.3 (2.2–3.4) | LrnD, ID, RLD, GenD | WISC-R FSIQ 89.4 ± 12.1 | - | P | - | Controls > ASD on non-meaningful sequential facial imitations. ASD = Controls on non-meaningful single facial imitations and single or sequential meaningful facial imitations |
| Rogers et al. (2003) | NS | Accuracy | 24 (20), 5:1 | 15.5 ± 3.1 (11–23) | TD, DD, GenD | MSEL NVMA 12–44 (23.7 ± 6.3) | - | P | - | TD > ASD, DD > ASD on oral imitation task. In ASD group, oral-facial imitation moderately correlated with ASD severity and joint attention, but not with EL |
| Samad et al. (2019) | NS | Magnitude | 10 (10) | 13.5 ± 2.4 | TD | Incl. criteria >70 | - | I | - | TD > ASD on activation magnitudes of FAUs and correlations between FAUs, although ASD > TD on activation of mouth frown |
| Schoen et al. (2011) | S | Accuracy, inventory, vocalization quality | 30 (23), 3.3:1 | 2.4 ± 0.4 (1.5–3.0) | TD | - | VABS EL AE 1.2 ± 0.4 | P | - | ASD > TD on number of atypical nonspeech vocalizations. TDA > ASD = TDL on number of early, middle, late, and total consonants. TDA > ASD on English consonant blends. ASD > TDA on number of atypical blends |
| Sheinkopf et al. (2000) | S | Duration, vocalization quality | 15 (13), 6.5:1 | 3.7 ± 0.7 | DD | MPSMT MA 22.13 ± 5.07 | RDLS EL AE 1.2 ± 0.2 | P | - | ASD = TD on proportion of syllables containing vowel sounds and proportion of syllables containing abnormally long vowels |
| Shriberg et al. (2001) | S | Accuracy, rate, intelligibility | 30 (30) | 5.8 ± 1.2 (4–7.9) | - | WISC-3 PIQ (89.0 ± 23.8) | HFA TLC:E (8.2 ± 4.0); AS TLC:E (8.3 ± 4.0) | P | - | HFA > TD and AS > TD on residual distortion errors. HFA > TD on “slow articulation/pause time” and “slow/pause time” ratings. HFA > AS on “slow articulation/pause time” ratings |
| Shriberg et al. (2011) | S | Accuracy, rate, consistency, duration, resonance, pausing | 46 (36), 3.6:1 | 6 ± 1.2 | TD, CAS, SSD | WISC-4 PIQ 67–149 (102.8 ± 16.1) | - | P/I | - | Results suggest a modest increase in risk of Speech Delay, substantial increase in risk of Speech Error, and no elevated risk for CAS in verbal ASD. ~55% of ASD sample had lengthened vowels, ~55% had increased percentage of phoneme distortion, and ~25% had slow speaking rate |
| Shriberg et al. (2019) | S | Accuracy, duration, formants, pausing | 42 (33), 3.7:1 | 21.2 ± 10.7 (10–49) | GenD, TBI | KBIT-2 (104.3 ± 15.7) | - | P/I | - | 83.3% of ASD group classified as normal speech acquisition, 16.7% with Speech Delay or Persistent Speech Delay, 0% with Speech Errors or Persistent Speech Errors. 85.7% of ASD group had no motor speech disorder, 14.3% had speech motor delay, 0% had childhood dysarthria or CAS |
| Spek et al. (2020) | F | Feeding difficulty | 89 (53), 1.5:1 | 38.5 ± 12 | TD | - | - | Q | SWEAA | ASD = TD on motor control for eating; within ASD group men had more motor control problems than women |
| Stevenson et al. (2017) | NS | Accuracy | 13 (9), 2.3:1 | 8 ± 4.1 (3–18) | TD | - | SCQ communication 6.9 ± 2.4 | Q | - | TD > ASD on oral motor skills. Oral motor skills were negatively correlated with autistic traits and positively associated with pragmatic language skills |
| Sullivan et al. (2013) | S | Accuracy, formants, rhythm | 39 (29), 2.9:1 | 1 ± 0.3 (1.5–2.5) | TD, DD | - | MSEL EL 26.9 ± 9.2 (20–56) | I | - | Some of ASD group ≠ TD on a measure associated with place of articulation. Articulatory features were significantly associated with RL in ASD group |
| Talkar et al. (2020) | S | Formants, coordination | 5 (5) | 7.2 ± 0.4 | TD | FSIQ 105–135 (124) | - | I | - | ASD > TD in the variance of F2 during syllable sequencing and free speech and in the variance of F3 during sustained vowels. Correlation between F0 and formant values during connected speech perfectly discriminated ASD versus TD |
| Thurm et al. (2007) | S/NS | Accuracy | 83 (71), 5.9:1 | (2–5) | DD | Various | Age 5 VABS composite EL AE ratio 0.4 ± 0.3 | Q | SICD, VABS-II | TD > ASD on parent reports of child imitating sounds of adults immediately after hearing them. Imitation of adult sounds discriminated groups which did and did not acquire EL at age 5 |
| Tierney et al. (2015) | S/NS | CAS dx | 11, 3.3:1 | (2–4.6) | - | - | - | P | KSPT | 63.6% of ASD group met criteria for CAS |
| Trembath et al. (2019) | S | Vocalization quality | 23 (17), 2.8:1 | 4.1 ± 0.8 (2.7–5.6) | - | MSEL-DQ 64.1 ± 21.9 | VABS EL 20.5 ± 11.8 (3–47); MSEL EL 22.9 ± 11.1 (7–46) | P | - | Change in vocalization ratio over time correlated with EL and nonverbal cognition; vocalizations per minute not correlated with language skills |
| van Dijk et al. (2021) | F | Feeding difficulty | 80 (55), 2.2:1 | 4 ± 1.1 (0–0) | TD | WPPSI/SON-R/BSID 90.32 ± 18.25 | - | Q | MCH-FS | ASD = TD on caregiver reports of chewing problems |
| Van Santen et al. (2010) | S | Duration | 26 | 6.6 ± 1.3 (4–8) | TD | WPPSI-3 PIQ/PRI (117.63 ± 11.48) | - | I | PEPS-C | ASD = TD on duration of syllables during lexical stress, emphatic stress, or contrastive stress tasks |
| Vashdi et al. (2020) | S | CAS dx | 170 | - | - | - | R | - | 61% of children with CAS or sCAS also had a dx of ASD | |
| Velleman et al. (2010) | S/NS | Accuracy, rate, consistency, duration, formants, pausing | 10 (9), 9:1 | 5.4 ± 0.9 (4.2–6.3) | TD, sCAS | NVIQ 70–90 | PLSA-EC (70.8 ± 15.6) | P/I/Q | VMPAC | Parents of 60% of ASD group reported signs of CD, CAS, or both. 6/10 in ASD group exhibited severe focal oromotor control deficits (one moderate), 4/10 exhibited severe speech motor deficits (four moderate). ASD > TD and ASD > sCAS on multiple formant values. ASD > TD on duration of some vowels. TD > ASD on average variation in speech duration |
| Vissoker et al. (2019) | F | Feeding difficulty | 105 (105) | 3.4 ± 4.3 (2–7) | TD | - | - | Q | AEQ | ASD > TD on caregiver reports of chewing and swallowing problems |
| Whitehouse et al. (2008) | S/NS | Accuracy | 34 (33), 33:1 | 10.8 ± 2.8 (7.2–15.8) | DLD | WASI 80–137 (105.0 ± 14.0) | ERRNI MLUw 89.8 ± 13.4 | P | NEPSY | ASD with language impairment > ASD with appropriate language on oromotor sequencing. ASD with language impairment > SLI on oromotor sequencing. Both ASD groups > SLI on sentence repetition. ASD with appropriate NWR skills = ASD without appropriate NWR skills on oromotor sequencing |
| Wynn et al. (2018) | S | Rate | 30 (21), 2.3:1 | 19.2 ± 10.4 (6–40) | TD | Adults >90 | Child group CELF-V EL 88.7 | I | - | TD adults entrained speech rate; ASD adults, ASD children, and TD children did not |
| Wynn et al. (2022) | S | Accuracy | 30 (21), 2.3:1 | 19.2 ± 10.4 (6–40) | TD | Adults >90 | Adequate to participate in task | I | - | TD > ASD on articulatory precision |
| Yan et al. (2021) | S | Accuracy | 30 (26), 6.5:1 | 5.7 ± 1.3 | TD | PTONI 59.53 ± 12.32 | - | P | - | Reduced phonemes correct at baseline |
| Yoder et al. (2015) | NS/F | Accuracy, inventory, feeding difficulty | 87 (71), 4.4:1 | 2.9 ± 0.6 (1.7–3.9) | - | MSEL MA 1:0 ± 0:5 | MCDI-WS 3.7 ± 5.0 (0–18) | P | OME, CSBS | Imitative and non-imitative oromotor skills did not have added predictive value for EL or RL among initially NV children with ASD |
| Zarokanellou et al. (2022) | S | Accuracy | 46 (35), 3.2:1 | 9.1 ± 1.5 (7–12) | TD | RCPM 104.8 ± 14.1 | EOWPVT-R raw score 63.3 ± 14.2 | P | TPPD | TD > ASD on nonword repetition, TD > ASD on speech accuracy |
Note: Greater than (>) and less than (<) indicate significant difference in performance.
a
F, feeding; NS, nonspeech; S, speech.
b
CAS, childhood apraxia of speech; DD, developmental delay; DLD, Developmental Language Disorder; ELD, expressive language disorder; GenD, genetic disorder; HR, high-risk siblings; HR−, high-risk siblings without ASD; HR+, high-risk siblings with ASD; ID, intellectual disability; LrnD, learning disability; MSD, motor speech disorder; RLD, receptive language disorder; sCAS, suspected childhood apraxia of speech; SSD, speech sound disorder; TBI, traumatic brain injury; TD, typically developing.
c
AE, age equivalent; BSID, Bayley Scales of Infant and Toddler Development; DAS, Differential Ability Scales; DR, developmental ratio; FSIQ, Full-Scale Intelligence Quotient; KABC, Kaufman Assessment Battery for Children; KBIT, Kaufman Brief Intelligence Test; LIPS, Leiter International Performance Scale; MA, mental age; MPSMT, Merrill-Palmer Scale of Mental Tests; MSEL, Mullen Scales of Early Learning; NV, nonverbal; NVDQ, Nonverbal Developmental Quotient; NVIQ, nonverbal IQ; NVMA, Nonverbal Mental Age; PIQ, Performance IQ; PRI, Perceptual Reasoning Index; PTONI, Primary Test of Nonverbal Intelligence; RCPM, The Raven’s Colored Progressive Matrices; RIAS, Reynolds Intellectual Assessment Scales; RPM, The Raven’s Progressive Matrices; SON-R, Snijders-Oomen nonverbal intelligence tests; TONI, Test of Nonverbal Intelligence; VR, Visual Reception; WAIS, Wechsler Adult Intelligence Scale; WASI, Wechsler Abbreviated Scale of Intelligence; WISC, Wechsler Intelligence Scale for Children; WPPSI, Wechsler Preschool and Primary Scale of Intelligence.
d
ADOS, Autism Diagnostic Observation Schedule; AE, Age equivalent; AS, Asperger syndrome; CELF, Clinical Evaluation of Language Fundamentals; DV, Definitional Vocabulary; EC, Expressive Communication; EL, Expressive Language; EOWPVT, Expressive One Word Picture Vocabulary Test; ERRNI, Expression, Reception and Recall of Narrative Instrument; EV, expressive vocabulary; EVT, Expressive Vocabulary Test; HFA, high-functioning autism; HTLF, Heidelberg Test of Language Development; IS, Imitation of Grammatical Structures; LUL, longest utterance length; MCDI, MacArthur-Bates Communicative Development Inventory; MLU, mean length of utterance; MLUw, Mean number of words per utterance; MSEL, Mullen Scales of Early Learning; NDW, Number of different words; NV, Nonverbal; OE, Oral Expression; OWLS, Oral and Written Language Scales; PLS, Preschool Language Scale; RDLS, Reynell Developmental Language Scales; SCQ, Social Communication Questionnaire; SPELT-P, Structured Photographic Expressive Language Test-Preschool; TLC, Test of Language Competence; TOPEL, Test of Preschool Early Literacy; V, Verbal; VABS, Vineland Adaptive Behavior Scales; WS, Words said.
e
I, instrumental; P, Perceptual; Q, questionnaire/report; R, medical record review.
f
See Table 2 for test names.
g
AS, Asperger syndrome; ASD, autism spectrum disorder; CD, childhood dysarthria; DDK, diadochokinetic; dx, diagnosis; EL, expressive language; FAU, facial action unit; FM, fine motor; GM, gross motor; HFA, high-functioning autism; NWR, nonword repetition; PDD-NOS, Pervasive Developmental Disorder-Not Otherwise Specified; RL, receptive language; SLI, specific language impairment; TDA, typically developing age-matched controls; TDL, typically developing language-matched controls.