Effects of an intensive voice treatment on articulatory function and speech intelligibility in children with motor speech disorders: A phase one study

What is it about?

This study examined changes in speech in children with cerebral palsy and Down syndrome following an intensive voice treatment program (LSVT LOUD). This work builds on previous studies that have shown improvements in vocal loudness and parent perceptions of speech following treatment. The authors wanted to examine articulatory acoustic measures of speech that may underlie improvements in how well these children are understood when they talk. This was a preliminary study with relatively small numbers of participants who were diverse in their severity of speech deficits.

Why is it important?

Measuring speech acoustics is an indirect way to understand how the jaw, tongue, and lips are moving in speech before and after treatment. Understanding how speech is, or is not, changing in these children after intensive voice treatment guides our efforts to improve the treatment. It also helps us determine the speech characteristics of children that may benefit more, or less, from this type of treatment approach.


For additional perspectives on this treatment study and line of treatment research, we asked lead researcher and co-author on this study Dr. Carol Boliek a few questions. Her insights are provided below.

Why did you want to study articulatory function following a voice treatment?

We wanted to know if spreading effects of LSVT LOUD to the articulatory subsystem occurred in children with CP and children with DS and whether or not these effects were similar to those observed in adults with PD following LSVT LOUD.

What were the key take away points from this study?

Spreading effects were observed in both groups of children.  Both groups showed improvements in overall intelligibility.  Improvements in vowel space were observed in children with CP and some children with DS.  The data indicate that improvements to articulatory precision occurred following LSVT LOUD in both of these pediatric populations.

How might this impact SLPs who are working with these children?

Our results indicate that by focusing on a single target (healthy vocal loudness), clinicians may also observe positive therapeutic changes to articulatory function and intelligibility.

“Treatment research for children with speech disorders secondary to cerebral palsy and Down syndrome is very limited. This arm of Dr. Boliek’s work has helped us understand the impact of intensive treatment directed towards the respiratory/laryngeal system in these children. The breadth of her work in this area spans perceptual, acoustic, physiological and neural studies. This impressive (and challenging) work has laid a solid foundation of early phase treatment research ready for expansion to randomized controlled trials.” -Cynthia M Fox, PhD, CCC-SLP, CEO LSVT Global, Inc.

Were there any surprises or key things you learned?

We were surprised at the robustness of the group findings, given our small sample sizes and the significant heterogeneity in clinical profiles represented by the children involved.

What happened next in terms of your research on LSVT LOUD?

We are now investigating changes in speech physiology (e.g., muscular effort, muscular coordination, and respiratory behaviors) following LSVT LOUD in a group of children with motor speech disorders and CP.  We are also looking at the effects of long-term post-treatment practice on the maintenance of skills achieved through LSVT LOUD in children with CP. This study included two methods of monitoring maintenance practice post-treatment using either traditional “paper and pencil” documentation or the LSVT Companion system. 

Access the full article abstract and citation HERE.


The LSVT Companion® is an invaluable data collection tool and treatment aide for the delivery of LSVT LOUD. It can now be used with persons of all ages.   

It is for persons of all ages with speech/voice impairments that result in inadequate loudness or control of loudness due to other neurological conditions or injury including stroke, traumatic brain injury, multiple sclerosis, ataxia, vocal fold paralysis, or other causes.

For use by voice/speech and/or hearing-impaired persons of all ages who are able to follow the directions of a speech therapist.

Learn more HERE.

Watch our on-demand webinar Application of LSVT LOUD® to Pediatric Motor Speech Disorders HERE

View our pediatric resources HERE

Read our blog post Intensive speech therapy (LSVT LOUD) for clients with Down syndrome and cerebral palsy – one clinician’s experience HERE