Hypophonia (low voice volume) is a common speech symptom for individuals with Parkinson’s disease. And, just like some of the motor symptoms which can come on gradually and pre-date a diagnosis, the changes in speech production can also have a subtle onset, hence, the PWP may not even recognize that voice or speech has changed. When a spouse or other close family member gives feedback “your mumbling,” “you’re talking to low,” the PWP may deny they have a problem, with a common retort that their partner “can’t hear.”

So, once enrolled in speech therapy, the goal is to improve speech production and bring volume back up to a more normal level for conversational speech. Sound easy?

Well, in some ways it is, and in fact, I maintain that I can cue just about any patient to be louder given 5 minutes. This is in part because we know that most people with PD can speak louder in response to an external cue. But when a verbal cue to speak louder brings speech into a more normal conversational level, many patients respond: “I feel like I’m shouting,” “this is too loud,” “I can’t talk this loud.”

So, the challenge facing therapists during speech treatment is instructing patients to practice at a high enough level of effort to actually strengthen their voice, while at the same time improving their perception of the problem.

Parkinson’s Causes Faulty Feedback

This overestimation by speakers with Parkinson’s disease of their own loudness (usually in the presence of reduced loudness of their speech) and/or a perception that they are shouting or producing abnormally loud speech, when asked to produced speech of “normal” loudness, as judged by the speech-language pathologist or another nonimpaired communication partner has been described as a sensori-perceptual disconnect. [i]

The basal ganglia (the problem center in PD) play an important role in the scaling and maintaining of movement amplitude and voluntary movement and the underscaling of movement amplitude is a PD symptom observed across numerous tasks including walking, writing, and speech.

But, while the automaticity of movement is affected, PWP can frequently modulate movement and voice amplitudes, particularly in response to an external cue using a verbal or a visual prompt. This discrepancy in performance can sometimes leave carepartners frustrated and asking: “why does he/she do it with you in therapy and not at home?”

A verbal cue alone may not be sufficient for some patients to maintain some level of improved motor performance, particularly with more advanced disease or concomitant cognitive impairment as it would require individuals to rely on their own proprioception and sensorimotor integration to detect and implement changes.

Augmented Feedback During Home Practice

An external source of feedback, such as the Hi-VOLT® light can supplement an individual’s own somatosensory and auditory feedback during motor skill learning. The Hi-VOLT® voice-on-light was designed to be used during daily voice practice for 30- 60 minutes daily. When used this way, the goal is to provide augmented feedback which may help with motivation to practice and also in setting a target for loudness, which may be greater than “feels normal,” but loud enough to yield a strengthening effect. Read more about Hi-VOLT here: https://voiceaerobicsdvd.com/parkinsons-advocacy/hi-volt-yield-statistical-and-perceptual-improvement-in-vocal-intensity-for-parkinsons-patients/

[i]Perception of Speech by Individuals with Parkinson’s disease.SAGE-Hindawi Access to Research
Parkinson’s DiseaseVolume 2011, Article ID 389767, 11 pages doi:10.4061/2011/389767


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