Impaired auditory discrimination and auditory-motor integration in hyperfunctional voice disorders

Area of Science:

• Speech, Language, and Hearing Sciences
• Neuroscience
• Otolaryngology

Background:

• Hyperfunctional voice disorders (HVDs), including vocal fold nodules and muscle tension dysphonia, are prevalent and significantly impact voice quality.
• The underlying mechanisms of HVDs remain largely unknown, hindering effective treatment development.
• Singing experience is known to influence auditory-motor function, necessitating its control in HVD research.

Purpose of the Study:

• To investigate the auditory-motor control of voice fundamental frequency (f_o) in individuals with and without HVDs.
• To determine if auditory discrimination and response to pitch perturbations differ between HVD and control groups.
• To explore the relationship between auditory function and motor control in the development of HVDs.

Main Methods:

• Compared auditory-motor control of voice f_o in 62 speakers with HVDs and 62 controls, matched for singing experience.
• Assessed auditory discrimination of voice f_o.
• Measured reflexive and adaptive responses to sudden and sustained f_o shifts, respectively.

Main Results:

• Individuals with HVDs demonstrated significantly worse auditory discrimination of voice f_o compared to controls.
• Reflexive responses to sudden f_o shifts were comparable between groups.
• Speakers with HVDs exhibited a higher frequency of atypical adaptive responses to sustained f_o shifts, linked to poorer auditory discrimination.

Conclusions:

• Impaired auditory discrimination is a key characteristic of HVDs, irrespective of singing experience.
• Atypical adaptive motor responses in HVDs are associated with deficits in auditory processing.
• Findings suggest a paradigm shift is needed to understand HVDs as disorders with significant auditory-motor control components, informing future treatment strategies.