Anywhere from 70-90% of persons with Parkinson’s have speech and voice problems, collectively referred to as hypokinetic dysarthria. Problems of reduced loudness, reduced effort, and inaccurate feedback are also related to a breakdown in the multisensory integration in our brain. As brain changes occur, many people with Parkinson’s mis-judge their voice and vocal effort, often reporting that their very soft speech is “loud enough” or even “too loud, and a cue to “speak up” and be normally loud often elicits the comment: “it feels like I’m shouting”. The pathophysiology underlying this impairment in internal cueing is only partially understood, but some speech studies indicate that different cueing mechanisms are located in different regions of the brain, with internally generated movements involving the basal ganglia, and frequently disrupted in Parkinson’s. This internal cueing deficit can often be improved in response to external cueing, for example, when one is asked to speak “twice as loud,” or when providing feedback from a sound level meter or other external device source. This improved motor speech response to an external cue movement involves a different region of the brain, the cerebellum.

Since the basal ganglia is also involved in helping us switch from one movement to the next, brain changes from Parkinson’s can also cause trouble with preprogramming and initiation of speech movements, which may be reflected in hesitancy, long pauses of silence, difficulty in starting a word, or difficulty in moving from one word to another.

However, speech and voice tend to improve dramatically in response to external cueing, many behavioral approaches to speech therapy take advantage of this effect, in hopes that patients will internalize the cue and begin to self-cue (e.g. “think loud”).

Unfortunately, for many individuals with Parkinson’s, they may be able to generate louder and clearer speech while in therapy with the speech therapist frequently cueing them, only to lose the effect once they leave the treatment room and are back home in their own environment.

This is not because of lack of effort on the part of an individual but rather, it is the challenge of trying to compensate for a motor speech mechanism that has been changed or is changing due to Parkinson’s. Dyskinesia and dystonia associated with fluctuations in medications can further contribute to an individual’s speech difficulties.

Could external feedback during speech practice in the clinic and at home help to strengthen voice and re-calibrate the system?

Hi-VOLT® 4 PD, a portable, calibrated, voice activated bracelet, was created with this goal in mind.


Hi-VOLT® use in Speech, Physical and Occupational Therapy

External feedback tools can be helpful to patients in and out of therapy, helping them re-calibrate to normal by seeing and feeling the effort associated with specific tasks such as walking and speaking.

Hi-VOLT® 4 PD is a calibrated, voice activated light bracelet, which can be used by individuals with Parkinson’s motor speech changes in and out of speech and physical therapy. Feedback from the Hi-VOLT ® voice-on-light can help the user gauge the level of loudness required to be understood by others. Since the light is calibrated, patients only must speak loud enough to activate the light. Housed within a bracelet, the Hi-VOLT can also be used in physical therapy helping patients maintain loudness while counting exercise reps.

Does it Work?

Using LSVT® Companion software, acoustic data was collected and analyzed on 98 patients at the time of their initial speech assessment. Patients performed a series of speech tasks un-cued and cued while using the Hi-VOLT® positioned 13” from their body and  a single cue: “be loud enough to activate the light.”

Hi-VOLT® yielded a change that was statistically significant and perceptually audible.

Re-calibration to more normal perception of speech/voice is the desired outcome from most speech therapy protocols for persons with PD, feedback tools which patients can utilize at home, on their own, may help them practice more effectively and improve or maintain strength of the respiratory and phonatory muscles. Hi-VOLT® 4 for PD is an affordable and portable device option I invite you to try.

To learn more or order a Hi-VOLT® light please visit:

My Mission: To enlist individuals in their treatment, and help them express their personality & spirit through voice. To educate  and empower. Mary Spremulli, MA, CCC-SLP * FiTOUR® Group Exercise Instructor * Voice Aerobics® A Whole Body Approach to Voice Practice

Voice Aerobics the heART and Science of Voice Practice