Five key differences between LSVT LOUD® and SPEAK OUT!®

What’s the difference between Lee Silverman Voice Treatment, LSVT LOUD and SPEAK OUT!? This is a frequent question posed by curious speech-language pathologists (SLP), healthcare professionals and patients with Parkinson’s.

In lay literature and on social media channels there is often little distinction made between these two treatments. However, take a closer look and it becomes clear there are significant differences.

Of utmost distinction is the 30 years of scientifically validated research and published patient outcomes that span perceptual, acoustic, physiologic, neurologic and patient reported outcomes for LSVT LOUD.

That is, “LOUD” by any name is not the same as LSVT LOUD.

1. Patient outcomes reported in published literature.

Both approaches are frequently described as evidence based. However, there is a difference when comparing the amount, level, and depth of evidence between these two programs.

In a recent systematic review of behavioral management of respiratory/phonatory dysfunction for dysarthria associated with neurodegenerative disease, Perry et al. (2024) concluded, “Synthesis of evidence quality provided strong evidence in support of only one behavioral intervention: Lee Silverman Voice Treatment Program (LSVT LOUD) in people with Parkinson's disease. No other treatment approach or population included in this review demonstrated more than limited evidence, reflecting that these approaches/populations require urgent further examination.” Read the article HERE.

Published research outcomes are summarized in the Read More section below and can be viewed in full detail in the links provided. The LSVT perspective that follows the chart provides a broader view of the 30 years of discovery and research from our team.

LSVT LOUD Publications: over 200 (1988-2023)

Speak Out Publications: 9 (2014-2021)

ASHA Evidence Maps for Parkinson’s disease

Published Research Outcome Data	LSVT LOUD	SPEAK OUT!
Systematic Reviews/Meta-Analysis Highest quality of evidence	Yes	No
Randomized Controlled Trials (RCT) Gold standard for establishing efficacy	7	0
Improved Vocal loudness in monologue Immediately Post-Treatment 6 months Post-Treatment 1 year Post-Treatment 2 years Post-Treatment	Yes-RCT Yes-RCT Yes-RCT Yes-RCT	Yes No Yes No
Improved voice quality	Yes - RCT	Yes
Improved intonation	Yes - RCT	Yes
Objective measures of improved swallowing*	Yes	No
Increased speech intelligibility in noise	Yes - RCT	No
Improved articulatory function	Yes	No
Increased facial expression	Yes	No
Improved respiratory kinematics	Yes	No
Changes in brain function for speech as measured by fMRI and PET	Yes - RCT	No
Improved vocal fold adduction	Yes	No
Increased laryngeal EMG	Yes	No
Improved speech motor stability	Yes	No
Improved patient self-reported voice and communication ratings (CETI-M, VHI, etc.)	Yes - RCT	Yes
Positive outcomes using telepractice delivery of treatment	Yes	No
Technology-enhanced delivery of treatment	Yes - RCT	No
Positive outcomes in multiple languages	Yes	No
Application in other adult populations (stroke, ataxia, multiple sclerosis)	Yes	No
Application in pediatric populations (cerebral palsy, Down syndrome)	Yes	No

*LSVT LOUD is not a direct swallowing treatment. Data document improvements in elements of swallowing post treatment but should not replace evidence-based swallowing therapies.

LSVT Perspective: What you do in therapy matters! Our research has found that it's not just general speech instruction that leads to positive outcomes, but rather specific activities targeted at the voice. These activities not only make the voice louder and more normal following LSVT LOUD, but they also improve many other aspects of speech, voice, and communication. Our imaging data indicates that LSVT LOUD may enhance the speech network in the brain, which includes sensorimotor and auditory regions. This enhancement is believed to produce lasting therapeutic effects over time.

This depth of research also provides confidence and assurance that you are providing or receiving treatment that has strong evidence to support its efficacy.

Protocol	LSVT LOUD	SPEAK OUT!
Application to other adult populations beyond Parkinson's	Yes	No
Application to pediatric populations	Yes	No

LSVT Perspective: These studies suggest there may be core components of LSVT LOUD that facilitate improvements in neural based disorders and conditions. The focus on voice as a foundation for speech, intensive and high effort treatment, consistent with principles of neuroplasticity, and sensory recalibration are well founded treatment principles.

Protocol	LSVT LOUD	SPEAK OUT!
Treatment Target/Focus	Vocal Loudness Directly target hypokinesia & bradykinesia in PD by driving amplitude through vocal loudness training	Intent Purposeful and deliberate cognitive focus on increasing attentiveness to speech production
Dosage Sessions	16 hours 60 min/4 days a week across 4 weeks	8 hours 40 min/3 days a week across 4 weeks
Cue in treatment	Speak Loud/Think Loud	Speak with Intent
Progressive hierarchy of speech complexity including cognitive linguistic practice	Yes	Yes
Home Practice Conversational carryover exercises	Yes Yes	Yes No
Sensory Recalibration	Directly Trained Focus attention on self-monitoring of increased vocal loudness to self-generate new loudness effort in speech	Not Directly Trained Focus on using intent to bypass automaticity of speech production

LSVT Perspective: The unique aspects of LSVT LOUD include the combination of (a) an exclusive target on increasing amplitude (loudness in the speech motor system) which results in cross-system effects such as improved articulation, facial expression and swallowing, (b) a focus on sensory recalibration to help patients recognize that a louder voice is within normal limits, even if they feel “too loud” and (c) training self-cueing and attention to action to facilitate long-term maintenance of treatment outcomes. The intensive LSVT LOUD dosage has been studied and found to be effective in over 200 publications over the last 30 years, with documented long-term retention of treatment gains.

The upside of intensive treatment is that it is 1) consistent with principles that drive neuroplasticity, 2) offers periodic bouts of intensive treatment followed by breaks in therapy, and 3) is an efficient way to effect change in a very short amount of time. Beyond intensity, LSVT LOUD incorporates other principles of neuroplasticity including repetitions, complexity, saliency, use it or lose it, and timing as summarized in this article. “Exercise is medicine” and intensity is essential for all forms of neurorehabilitation (Learn more here).

Protocol

LSVT LOUD

SPEAK OUT!

Maintenance

Optional, periodic

LOUD for LIFE

Required, indefinite

LOUD Crowd

LSVT Perspective: The follow-up periods in published research studies have documented that LSVT LOUD effects can last at least six months, and potentially out to two years without any additional treatment. In the clinical world, maintenance can include both exercise classes and periodic tune-up sessions. There are clinical reports of LSVT LOUD effects lasting much longer than two years for some clients, but these have not been documented with research.

Protocol	LSVT LOUD	SPEAK OUT!
Multi-disciplinary counterpart	LSVT BIG	None

LSVT Perspective: LSVT LOUD and LSVT BIG are parallel treatments, the latter delivered by physical or occupational therapists. LSVT BIG aims to enhance mobility, balance, and overall quality of life by increasing the amplitude of movement, just like LSVT LOUD. This shared goal of amplitude improvement allows for multiple clinicians to collaborate and work towards the same therapeutic objective. The combination of these two approaches offers patients a holistic and interdisciplinary treatment package with a focus on restoring normal amplitude, which entails speaking louder and moving bigger.

Summary: Less than 30 years ago, published literature stated that “speech treatment for Parkinson’s disease does not work.” This served as a catalyst for change and the start of what is today, LSVT LOUD. Countless hours by researchers and clinicians and millions of NIH dollars have gone into establishing solid science that disputes this claim; documenting that LSVT LOUD speech treatment both works and lasts in people with Parkinson’s. Further, the underlying mechanisms of how this effective treatment works have been explored through acoustic, perceptual, physiological, and neural imaging studies. Detailed elements of what makes treatment successful, or not, are defined by this systematic research process and inform our clinical protocols and guide our application beyond Parkinson’s (other neural disorders in adults and children) and to movement (LSVT BIG).

LSVT LOUD and SPEAK OUT! are both speech therapy programs designed to improve the communication abilities of individuals with Parkinson's disease. However, as you look at the treatment programs more carefully, you see significant differences, and you can use this information to inform and guide your treatment and training decisions.

by any other name...is not the same

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