A 2025 study by Kim and colleagues investigated the effectiveness of LSVT LOUD® – a voice therapy program originally designed for people with Parkinson’s disease – for adults with cerebral palsy (CP). The research tested both in-person and telehealth versions of the extended LSVT-X protocol (16 session over 8 weeks, read original study by Spielman et al., 2007). Outcome measures focused on voice and speech, swallowing, and quality of life. The study included 16 adults with CP, ranging from mild to profound speech impairments.
Key findings of the study are highlighted below. These measures reflect immediate pre to post treatment changes.
1. Voice & Speech Outcomes
Both in-person (LSVT-X) and telehealth (LSVT-X e-LOUD®) groups showed gains in:
- Maximum phonation time: Sustaining an “ah” sound on one breath
- Voice intensity*: Increased loudness for LSVT-X e-LOUD group
- Articulation agility: Faster syllable repetition, which may contribute to clearer speech
While these specific measures improved, overall ratings of dysarthria severity didn’t change immediately post-treatment.
*Note: It was not clear how the voice intensity data were analyzed, or which tasks (e.g. maximum phonation, reading or conversation) were included in the reported data.
2. Swallowing Outcomes
Videofluoroscopy examination (VFSS) revealed:
- More efficient swallowing with 5ml and 15ml liquid volumes
3. Quality of Life Gains
Participants reported:
- Reduced voice-related challenges (Voice Handicap Index, p=0.001)
- Fewer swallowing fears (SWAL-QOL, p=0.031)
4. Telepractice Success
The online LSVT-X e-LOUD® group achieved comparable results to in-person therapy, highlighting its accessibility potential.
Why This Matters for CP Care
CP often causes lifelong speech (dysarthria) and swallowing (dysphagia) challenges, yet many adults receive limited direct therapy. This study extends LSVT LOUD’s evidence base beyond Parkinson’s, showing promise for CP care. Critically, over 60% of participants had severe/profound speech impairments – a group often excluded from traditional interventions.
Limitations & Next Steps
While promising, the study had key limitations:
- Small sample size (16 participants)
- No long-term follow-up data
- Unclear methodology for analyzing and reporting vocal intensity
- Lacked assessments of speech intelligibility or listener perceptions
Future studies should explore:
- Larger trials across CP subtypes
- Hybrid therapy models (in-person + telehealth)
- Cost-effectiveness analyses of telepractice
- Standardized homework protocols (current study utilized 5-10 minutes twice a day for non-treatment days; 10-15 minutes twice a day for non-treatment days was reported in original study).
The Bottom Line
This research offers preliminary evidence that LSVT LOUD® – delivered in-person or remotely – could help adults with CP improve select aspects of vocal and speech control, swallowing safety, and quality of life. While not a replacement for dedicated swallowing therapy, it may offer complementary benefits. For clinicians, these findings underscore the value of intensive voice therapy even for severe speech impairments.Want to dive deeper? Clinicians can access the full study here.
Kim, K. M., Park, S. A., Hwang, S. H., Park, A., Kim, H. H., Hwang, J., & Cho, S. R. (2025). Efficacy of in-person and telepractice-based extended Lee Silverman Voice Treatment LOUD® on dysarthria and dysphagia in adults with cerebral palsy. Digital health, 11, 20552076251315296. https://doi.org/10.1177/20552076251315296
