An interventional study of LSVT-LOUD Therapy in Parkinson's Disease (PD), sponsored by Atlas University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 40 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-07-28.
Sponsored by Atlas University · Not applicable, Interventional, and Supportive care
Parkinson's disease often causes speech and voice impairments, such as reduced vocal loudness and decreased speech intelligibility, which significantly impact the quality of life for patients and their families. The Lee Silverman Voice Therapy-LOUD (LSVT-LOUD) is a specialized, evidence-based speech therapy protocol designed to improve vocal function.
This study investigates the effectiveness of the LSVT-LOUD protocol in Turkish-speaking individuals with Parkinson's disease. The research evaluates objective changes in vocal loudness and speech quality, as well as the subjective therapy experiences of participants. By analyzing both clinical outcomes and patient feedback, this study aims to contribute to the clinical application and adaptation of LSVT-LOUD for the Turkish-speaking population
This study implements the standardized Lee Silverman Voice Treatment (LSVT-LOUD) protocol, an intensive intervention focused on the recalibration of vocal effort through motor learning principles. The intervention requires participants to attend individual therapy sessions conducted four times per week over a four-week period, with each session lasting 60 minutes.
The protocol emphasizes high-effort phonation and is structured into the following components:
Daily Tasks: Sustained vowel phonation (maximum duration and stability), pitch range exercises (high-to-low and low-to-high glides), and maximum functional loudness drills using high-effort speech.
Hierarchy Tasks: Systematic progression from word-level to sentence-level and, finally, conversational speech tasks, incorporating high-effort vocal production into increasingly complex linguistic structures.
Carry-over Exercises: Daily practice assignments designed to facilitate the generalization of high-effort speech into activities of daily living and social interactions.
Clinical instruction emphasizes the patient's sensory perception of vocal effort, using acoustic feedback to help participants recalibrate their internal perception of 'loud' versus 'normal' speech. The protocol is conducted in Turkish, adhering to the original LSVT-LOUD methodological requirements while accounting for linguistic nuances of the Turkish language.
4,573 studies on the registry are indexed under Parkinson Disease; 1,086 are open to participants now.
This study's planned enrollment of 24 is below the median of 40 across 3,353 interventional studies indexed under Parkinson Disease.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Diagnosis: Patients with a confirmed diagnosis of Idiopathic Parkinson's Disease (Hoehn and Yahr stages I-III).
Age: Individuals aged 40-80 years.
Language: Native Turkish speakers.
Cognitive Status: Sufficient cognitive function to participate in therapy (e.g., (MMSE) score ≥ 24).
Communication: Presence of voice or speech impairment (e.g., hypophonia, reduced intelligibility) as confirmed by a speech-language pathologist.
Stability: Stable medication regimen for at least 1 month prior to the study initiation.
Exclusion Criteria:
Neurological Comorbidities: Presence of other significant neurological disorders (e.g., stroke, traumatic brain injury, multiple sclerosis) or active voice disorders (e.g., vocal cord nodules, laryngeal cancer).
Hearing Impairment: Uncorrected hearing loss that would interfere with speech assessment or therapy.
Cognitive Impairment: Diagnosis of dementia or severe cognitive impairment that prevents participation in the intensive LSVT-LOUD protocol.
Recent Surgery: History of laryngeal surgery or deep brain stimulation (DBS) within the last 6 months.
Therapy History: Previous experience with LSVT-LOUD or intensive speech therapy within the past year.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
MMSE and MoCA
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
"Participants in this arm receive the standard Lee Silverman Voice Therapy (LSVT-LOUD) protocol. The intervention consists of intensive, high-effort vocal exercises designed to increase vocal loudness and improve speech intelligibility. The protocol is administered in 4 sessions per week, with each session lasting 60 minutes, over a total duration of 4 weeks. The therapy focuses on maximizing vocal output through calibrated exercises, including sustained phonation, pitch range exercises, and functional speech tasks. Additionally, participants are provided with carryover exercises to practice at home to ensure long-term maintenance of improved vocal and speech functions .
Behavioral: LSVT-LOUD Therapy
Participants in the control group receive standard medical care for Parkinson's disease, with no specific intensive speech therapy intervention provided during the study period
The LSVT-LOUD protocol is a structured, intensive speech treatment specifically designed for individuals with Parkinson's disease. The intervention follows a standardized format: 4 individual 60-minute sessions per week for 4 consecutive weeks (total of 16 sessions). The core exercises include: Daily Tasks: Sustained phonation (holding 'ah' at a loud, stable pitch), pitch range exercises (high and low), and maximum duration of vowel phonation. Functional Speech Tasks: Practicing high-effort vocalization using functional phrases, sentences, and hierarchical reading/conversation tasks in clinical sessions. Carryover Exercises: Daily homework and 'real-world' assignments to facilitate the generalization of increased vocal loudness and speech quality into everyday life. The therapy emphasizes high-effort motor output, sensory recalibration (helping the patient perceive their 'loud' voice as normal), and intensive repetition to maximize neuroplasticity and therapeutic outcomes.
Qualitative Therapy Experience
Semi-structured interview form conducted with participants and their primary caregivers to explore subjective therapy experiences, including motivation, challenges, perceived benefits, and communication improvements. Analysis performed using thematic analysis methods.
Time frame: Post-therapy (4 weeks)
Vocal Intensity (Loudness)
Measured through acoustic analysis of sustained phonation and standardized speech tasks to evaluate changes in vocal intensity. - Decibels (dB)
Time frame: Baseline (pre-therapy), post-therapy (4 weeks), 1-month follow-up, and 3-month follow-up.
Acoustic Voice Stability (Jitter and Shimmer)
Evaluation of vocal stability by measuring cycle-to-cycle variability in fundamental frequency (Jitter) and amplitude (Shimmer) during sustained vowel phonation. - Unit of Measure: Percentage (%)
Time frame: Baseline (pre-therapy), post-therapy (4 weeks), 1-month follow-up, and 3-month follow-up.
Fundamental Frequency (F0)
Mean fundamental frequency of the voice during sustained phonation. - Hertz (Hz)
Time frame: Baseline (pre-therapy), post-therapy (4 weeks), 1-month follow-up, and 3-month follow-up.
Voice Handicap Index (VHI)
Total score of the Voice Handicap Index (VHI) to assess the impact of voice problems on quality of life. - Score (Scale: 0-43)
Time frame: Post-therapy (4 weeks)
Parkinson's Disease Questionnaire (PDQ-39)
Assessment of Parkinson's disease-specific health-related quality of life using the Parkinson's Disease Questionnaire (PDQ-39). The questionnaire evaluates several domains including mobility, activities of daily living, emotional well-being, and communication. Unit of Measure: Score (Scale: 0-156)
Time frame: post-therapy (4 weeks)
Plan to share: Yes — De-identified individual participant data (IPD) will be made available upon reasonable request to qualified researchers who provide a methodologically sound proposal for secondary analysis. Data access will be granted for purposes approved by the study's ethics committee and in compliance with the principles of participant confidentiality and informed consent. Requests should be directed to the corresponding author via email, including a brief research protocol and a statement regarding the intended use of the data
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: pon publication of the thesis and related manuscripts
Access criteria: Access to individual participant data (IPD) and supporting documentation (study protocol, statistical analysis plan, and clinical study report) is provided to qualified researchers, academic institutions, and clinicians who demonstrate a legitimate scientific interest and a methodologically sound research proposal.
Data sharing details ↗ · tez.yok.gov.tr
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