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The Science and Practice of “Speaking LOUD”

By Lorraine Ramig, Ph.D., CCC-SLP and Cynthia Fox, Ph.D., CCC-SLP

If you don’t talk loud enough — people stop listening.

If I have no voice, I have no life.

These are direct quotes from two individuals who live with Parkinson disease (PD). They reflect the devastating impact that a speech and voice disorder can inflict on the quality of life of a person with PD.

These two are not alone. Research shows that 89 percent of people with PD experience speech and voice disorders, including soft voice, monotone, breathiness, hoarse voice quality and imprecise articulation. As a result, people with Parkinson’s report that they are less likely to participate in conversations, or to have confidence in social settings, than healthy individuals in their age group.

For years, speech and voice disorders in people with PD were resistant to treatment. The effects of conventional treatments — whether medical or surgical — were neither significant nor lasting. The recognition that speech therapy could be tailored to the specific problems of the Parkinson’s patient led to the development of a method aimed at improving vocal loudness: the Lee Silverman Voice Treatment (“LSVT® LOUD”) method. This technique has helped many individuals with Parkinson’s disease and speech problems, giving them new hope for improved communication for work, family and social activities.

Speech and voice disorders in PD

There are several reasons why people with PD have reduced loudness, monotone and hoarse, breathy voice. One is directly related to the disordered motor system that accompanies PD, including rigidity, slowness of movement and tremor. For example the inadequate muscle activation that leads to bradykinesia (slow movement) and hypokinesia (small movements) in the limbs can also trigger a speech disorder. For speaking, the problem with muscle activation can result in reduced movements of the respiratory system (reduced breath support), larynx (reduced vocal loudness), and articulation (reduced clarity of speech).

Another cause of speech and voice impairment in Parkinson’s is a deficit in the sensory processing that is related to speech. Clinical observations suggest that people with Parkinson’s may simply not be aware that their speech is getting softer and more difficult to understand. When “soft speaking” people are told of this, they will often reply, “No, my voice is not too soft! My spouse complains all the time, but he/she needs a hearing aid!” Furthermore, if people in this situation are asked to bring their voice to normal loudness, they will often complain that they feel as though they are shouting, even though they are perceived by listeners to be speaking normally.

A third cause of this condition is that people with Parkinson’s may have a problem with “cueing” themselves to produce speech with adequate loudness. Individuals with PD can respond to an external cue (e.g., an instruction from someone else to “speak loudly!”), but their ability to cue themselves internally to use a louder voice is impaired. These problems can be frustrating both for the person and for the family. Patients feel that they are speaking loudly enough and do not understand why people keep asking them to repeat. And because speech loudness responds to external cueing — sometimes soft, sometimes normal — the family may feel that the patient can be louder and clearer if they would only try harder.

These motor sensory and cueing problems have made people with Parkinson’s particularly resistant to speech treatment. Conventional wisdom has been that people with PD can improve their speech during the speech therapy session, but the improvement “disappears on the way to the parking lot.” As a result, conventional speech therapy has not led to sustained benefit, and has not been considered a valuable addition to the treatment of Parkinson’s.

Speech therapy: LSVT® LOUD

“My voice is alive again!”

Over the past 15 years, studies supported by the National Institute for Deafness and other Communication Disorders (NIDCD) of the National Institutes of Health have demonstrated that LSVT® LOUD is an effective speech treatment for people who live with Parkinson’s. Those who have used it have improved their vocal loudness, intonation and voice quality, and maintained these improvements for up to two years after treatment.

Recent research studies have also documented the effectiveness of this therapy in meeting the common problems of disordered articulation, diminished facial expression and impaired swallowing.

In addition, two brain-imaging studies have documented evidence of positive changes in the brain following administration of the therapy.

LSVT LOUD improves vocal loudness by stimulating the muscles of the voice box (larynx) and speech mechanism through a systematic hierarchy of exercises. Focused on a single goal — “speak LOUD!” — the treatment improves respiratory, laryngeal and articulatory function to maximize speech intelligibility (see graphic on this page). It does not train people for shouting or yelling; rather, the treatment uses loudness training to bring the voice to an improved, healthy vocal loudness level with no strain.

The program is administered in 16 sessions over a single month (four 60-minute sessions per week). This mode of administration — much more intensive than conventional programs — is consistent with theories of motor learning and skill acquisition, as well as with principles of neural plasticity (i.e., the capacity of the nervous system to change in response to signals), and it is critical to attaining optimal results. In addition to stimulating the motor speech system, the treatment incorporates sensory awareness training to help individuals with PD recognize that their voice is too soft, convincing them that the louder voice is within normal limits, and making them comfortable with their new louder voice.

Patients are trained to self-generate (that is, internally cue) the adequate amount of loudness to make their speech understood. While LSVT LOUD has been successfully administered to individuals in all stages of PD, it has been most effective among those who are in the early or middle stages of the condition.

How to get LSVT LOUD

LSVT LOUD is now a globally standardized treatment, and there are speech therapists in 32 countries around the world who are trained and certified by the LSVT® Foundation to deliver the treatment protocol in a standardized and tested way.

If you are experiencing any changes in your speech or voice, be sure to tell your doctor. Ask for a referral and a prescription for a speech evaluation and treatment. If you have not noticed changes in your speech, but a spouse, caretaker, or friend has: pay attention to their comments. One aspect of the speech disorder is that the person with PD is often unaware of the changes in speech or voice. The sooner you obtain a speech evaluation and start speech therapy, the better.

Speech therapists work in a variety of settings, including hospitals, out-patient rehabilitation centers, and private practice offices. To locate one in your area, contact the American Speech-language-Hearing Association (ASHA), or find an LSVT-certified speech therapist by visiting

Ideally, you should see a speech therapist face-to-face for a complete voice and speech evaluation and treatment. However, if a speech therapist is not available in your area, LSVT LOUD is now being offered in selected states via internet and webcam technology. The speech therapist interacts with you in your home or office “live” through your computer screen.

Speech disorders can progressively diminish quality of life for a person with Parkinson’s disease. LSVT LOUD empowers people with PD to participate in their treatment in fundamental ways and to gain control over one important and burdensome aspect of their PD: the ability to communicate. The earlier a person with PD receives a baseline speech evaluation and speech therapy, the more likely he or she will be able to maintain communication skills as the disease progresses. Communication is a key element in quality of life and can help people with PD maintain confidence and a positive self-concept as they deal with the challenges of the disease.

For information on LSVT LOUD, contact the LSVT Foundation by calling (888) 606-5788 or email For a full list of the research studies referenced in this article, visit or

Dr. Ramig is a Professor at the University of Colorado-Boulder, Senior Scientist at the NationalCenter for Voice and Speech (Denver), Adjunct Professor, Columbia University, New York City and President of the LSVT Foundation. Dr. Fox is a Research Associate at the National Center for Voice and Speech in Denver and Research Lecturer in the Department of Neurology at the University of Arizona. She is also Executive Vice President of the LSVT Foundation.