Many people with Parkinson’s disease run into a common friction with the people around them. The patient feels that the speaking volume is normal, but family members and caregivers keep saying that they cannot hear what is being said. This is not because the family’s hearing has declined, and it is not because the patient is speaking quietly on purpose. It comes from a particular neurological mechanism in Parkinson’s disease: a sensory processing deficit. The patient’s brain misjudges the patient’s own volume, so the patient believes the speech is at a normal volume, while others hear it as barely audible. For this phenomenon, the speech treatment for Parkinson’s disease with the best evidence, LSVT LOUD, uses a core of training that goes against intuition: the patient is trained to speak louder on purpose, and clearer speech is expected to follow. This article explains in detail the three main speech problems of Parkinson’s disease, the principle and research evidence behind LSVT LOUD, the swallowing difficulty specific to PD, and strategies for keeping the benefit going with practice at home.
Three common speech problems in Parkinson’s disease
Speech problems caused by Parkinson’s disease are known in medicine as hypokinetic dysarthria. The cause is degeneration of the neural motor pathways that control voicing, which weakens the coordination between breathing, the vocal folds, the tongue and the lips. The symptoms fall mainly into three groups.
Research indicates that speech problems affect nearly nine in ten people with Parkinson’s disease, and greatly reduce their quality of life and social participation (Mahler et al., 2015). Unfortunately, many patients and families mistakenly regard these problems as an inevitable result of the disease getting worse, and accept them with resignation. In fact, targeted speech therapy can bring real improvement.
The core principle of LSVT LOUD
LSVT LOUD (Lee Silverman Voice Treatment, named after Lee Silverman, the first patient to receive this therapy) is a speech therapy programme developed by Dr Lorraine Ramig and her team. It is the speech intervention for Parkinson’s disease with the most randomised controlled trials supporting it.
The focus of LSVT LOUD training is to make the voice louder, with clearer speech expected to follow. Through repeated practice, the patient voices much more loudly than usual with effort. The brain’s reference level for volume is recalibrated, and speaking loudly gradually comes to feel natural. Once volume goes up, clarity of articulation, rise and fall of intonation and accuracy of speech sounds improve together, because the root of these problems is that the voicing movements are too small.
The standard LSVT LOUD course is 4 sessions a week for 4 weeks, a total of 16 high-intensity sessions of about 1 hour each. Sessions are built around three core exercises, together with functional speech training (such as reading aloud everyday sentences and role-play conversations). The final goal is for the patient to be able to monitor speaking volume independently in everyday communication.
- 1Sustained vowelHolding the “ah” sound as long as possible at maximum volume, to train breath support and the force of vocal fold closure.
- 2Pitch glidesGliding with effort from the lowest pitch up to the highest and back down, to train changes in pitch and the flexibility of the muscles of the larynx.
- 3Functional phrasesPractising speaking loudly with sentences from everyday communication (such as introducing oneself and asking for directions), to carry the training from the session into real life.
- 4Daily monitoringTeaching the patient to pay attention to their own volume when talking, and to deliberately keep it at the level that “feels too loud”.
Evidence for LSVT LOUD
LSVT LOUD has more than thirty years of clinical research behind it. Several randomised controlled trials consistently show that it effectively improves the speech of people with Parkinson’s disease, and that the benefit lasts.
A large RCT (n=64) published in 2018 by Ramig et al. in the journal Movement Disorders further confirmed that LSVT LOUD was significantly better at raising volume than the LSVT ARTIC group, which concentrated on articulation, and than the untreated control group (p<0.05). At 7 months of follow-up, only the LSVT LOUD group still had a significant improvement in communication effectiveness (CETI-M) (p=0.0011). These data show that, for lasting communication effectiveness, the strategy of practising loudness works much better than correcting articulation directly.
- Directly corrects individual consonants and vowels
- Can improve communication effectiveness in the short term (1 month)
- The advantage in communication effectiveness faded at 7 months of follow-up
- Does not address the root problem: voicing movements that are too small
- Trains overall voicing volume and size of movement
- Volume, clarity and intonation improve together
- Benefit remained significant at 7 months and 2 years of follow-up
- Targets the neurological mechanism of Parkinson’s disease (recalibrating the sensory baseline)
Swallowing difficulty and silent aspiration in Parkinson’s disease
Swallowing difficulty (dysphagia) can appear at different stages of Parkinson’s disease, and it is estimated to affect more than two thirds of patients. Its mechanism differs from that of stroke and other neurological diseases, and two high-risk problems are specific to people with PD: silent aspiration and abnormal oesophageal motility.
Warning signs of swallowing difficulty in PD
- Meals take much longer than before
- Each mouthful needs several swallows before it is fully swallowed
- The voice sounds “wet” or hoarse after eating
- Repeated fever or pneumonia with no clear cause
- Continued weight loss and poorer appetite
- Avoiding or fearing certain textures of food or drink
Swallowing problems specific to PD
- Silent aspiration: food or liquid enters the airway with no cough at all, so it is hard to notice
- Weaker pharyngeal motility: after swallowing, the throat does not clear all the food residue
- Abnormal oesophageal motility: food stays in the oesophagus too long
- More drooling: not because more saliva is produced, but because the patient swallows saliva automatically less often
- Medication fluctuations affect swallowing: in the “off” period when the medication wears off, swallowing is clearly worse
A study of 74 people with Parkinson’s disease found that 42% had aspiration on endoscopic assessment, and 68% of these had silent aspiration, meaning that the patient had no cough response at all when food entered the airway (Martell et al., 2024). Silent aspiration is often the cause of repeated aspiration pneumonia. It is hard for family members to notice, and the patient may not know either. If an older person with Parkinson’s disease has repeated fever, a speech therapist should do a swallowing assessment soon, even if there is no choking at mealtimes.
In managing swallowing problems in Parkinson’s disease, besides general routine care, the time window in which the medication works also has to be taken into account (arranging meals in the “on” period when the medication is at its best where possible), and changes in swallowing as the disease progresses need to be watched closely. The speech therapist’s role is wide. It includes carrying out a clinical swallowing assessment (or referring for an instrumental assessment), advising on texture of food and drinks according to the IDDSI standard, teaching safe swallowing techniques (such as the effortful swallow and chin-tuck swallow), and guiding the patient through expiratory muscle strength training (EMST) to improve swallowing safety.
What EMST does for swallowing in PD
Expiratory muscle strength training (EMST) uses a breathing trainer with a resistance valve to exercise the muscles used for breathing out. Several studies indicate that EMST strengthens the cough (which helps to cough out anything that has entered the airway) and also improves how far the hyoid bone and larynx complex rise, which directly protects swallowing safety.
A daily home voice practice plan
The key to keeping the benefit of LSVT LOUD is to keep practising at home every day after the course ends. Research shows that once training stops, the expiratory muscle strength and voice improvement that took effort to build slowly fade, while regular home training can effectively slow the decline and consolidate the results of treatment.
- Daily sustained vowel—Hold the “ah” sound at maximum volume for at least 5 seconds, and repeat 5–10 times. This core exercise helps to keep up breath support and the force of vocal fold closure. One set in the morning and one in the evening is suggested, about 5 minutes each time.
- Pitch glides—Glide when voicing from the lowest pitch up to the highest (for example raising the pitch on the “ah” sound), and then back down to the low pitch, repeating 5–10 times. This trains changes in pitch and stops the intonation from becoming flat and monotonous.
- Loud functional conversation—Each day, choose a real conversation (for example at a meal with family, or on the phone) and deliberately speak at a volume that “feels too loud”, and ask family members to give feedback on the spot. This step is very important for turning the training in the session into a daily habit.
- Practice in the medication window—Arrange the daily voice practice in the “on” period when the dopamine medication works best (30–90 minutes after taking it). Muscle control is best during this time, and so are the practice results.
- Morning: hold the vowel “ah” at maximum volume, 5–10 times
- Morning: pitch glides up and down, 5–10 times
- During the day: deliberately keep to the volume that “feels too loud” when chatting
- Evening: read aloud everyday text (such as news headlines, recipes or poems) loudly for 5 minutes
- Practise in the “on” period when the medication works best (30–90 minutes after taking it)
- Each month, have family members rate the patient’s speaking volume, to see whether the effect is being kept up
- If the speaking volume clearly declines within two weeks, contact the speech therapist soon for a review
The follow-up study by Troche et al. (2014) after training stopped found that 3 months after stopping EMST training, the patients’ maximum expiratory pressure had fallen back but was still about 17% above the baseline before treatment. This shows that regular home training has a lasting protective effect, and that the results of treatment do not disappear straight away once the formal course ends. If practice is given up altogether, however, ability will gradually decline. Building a habit of daily voice exercise is therefore as important as long-term management of the disease.
Features of home speech therapy
For a person with Parkinson’s disease, keeping the results of speech training in real daily life is often much harder than practising in a therapy room, since the patient ultimately needs to express themselves clearly at home and with family. Home speech therapy brings the training setting straight into the patient’s daily life.
Benefits of home therapy
- Practising in the familiar home environment makes the skills learned easier to bring into everyday conversation
- The speech therapist can see on site how the patient and family usually communicate
- In a swallowing assessment, the food the patient usually eats and the utensils usually used can be used directly
- Caregivers can learn alongside, and master how to remind the patient about volume on the spot
- No travelling, so fewer missed sessions caused by difficulty moving or by fluctuations in the “off” period
Situations that suit a home assessment
- Parkinson’s disease has been diagnosed, and the patient has started to speak quietly or has difficulty communicating
- Family members often say they cannot hear what the patient says, while the patient thinks the volume is normal
- There are early signs of swallowing difficulty (for example eating slowly, or a wet voice after eating)
- After returning home from hospital, speech and swallowing rehabilitation needs to continue
- The patient has difficulty moving and finds it hard to attend a clinic in person
Frequently asked questions
Parkinson’s disease often affects both speaking and eating. To read more about swallowing safety, the IDDSI food texture levels and professional assessment of silent aspiration, see speech therapy for swallowing difficulty. If an older person at home is using a nasogastric tube and you want to know whether it is possible to move safely back to eating by mouth, see nasogastric tube removal assessment. To find out more about the different speech therapy services, visit the home speech therapy main page.
Is the voice getting quieter in Parkinson’s disease, is the speech unclear, or are you worried about a family member’s swallowing safety? Our registered speech therapists can assess at home and provide LSVT LOUD training and an individual home practice plan. Enquire instantly on WhatsApp, and we generally reply within 1 hour.
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