Direction of Cepstral Peak Prominence Change Moderates Divergent Kinematic Responses to Voice Stimulability Testing.
Laura E Toles, Sarah McDowell, Melanie Turner Tice and 1 others
Stimulability testing did not produce uniform changes in vocal fold movement across 27 women with voice lesions.
The direction of an acoustic measure (CPP) split the group into two subgroups showing opposite kinematic shifts. Patients reach the same perceptual improvement through different physiological routes.
Key findings
1No high-speed videoendoscopy kinematic measure showed a statistically significant group-level change after stimulability testing; all comparisons were nonsignificant at the corrected significance thresholds.
2In an exploratory analysis, the direction of CPP change (increase vs decrease) significantly moderated the kinematic response, with significant Time × CPP interactions for Closing Quotient (p = .003), Speed Index (p = .046), and Stiffness Index (p = .035).
3The two subgroups moved in opposite directions: the CPP-increase group showed a decrease in Closing Quotient (Δ = −0.04, d = 0.77) while the CPP-decrease group showed an increase (Δ = 0.06, d = 1.07), and the CPP-decrease group also showed lower Stiffness Index post-testing (Δ = −151.47, p = 0.041, d = 0.86).
Still to come
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Sample of 27 limits statistical power, especially for the interaction effects in the exploratory aim; the authors state replication with larger samples is needed. CPP change was split into two categories (increase vs decrease), which simplifies a continuous variable and may mask more gradual relationships. High-speed videoendoscopy captures vocal fold kinematics but not supraglottic or laryngeal behaviors that also contribute to perceptual voice changes. All 27 participants reported improvement, so the study says nothing about patients who do not respond to stimulability testing. Single-group pre-post design with no control condition; the SLP delivered all facilitators and cues, so the response cannot be separated from the clinician's influence.
Declared interests
The authors declare no conflicts of interest.
The easy way to misread this
Do not read the significant interaction effects as proof that CPP reliably predicts a patient's kinematic response. The primary group-level hypothesis was not supported (all comparisons nonsignificant at corrected α =.010 and α =.0167), the interaction analysis was explicitly labelled exploratory, and the sample of 27 limits power for detecting interactions. The authors themselves call for replication with larger samples before these findings can guide clinical decisions.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →