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

Defne Abur,Austeja Subaciute,Cara E Stepp,Roxanne K Segina,Lauren F Tracy,J Pieter Noordzij,Mara Kapsner-Smith

doi:10.1038/s41598-021-92250-8

Abstract

Hyperfunctional voice disorders (HVDs) are the most common class of voice disorders, consisting of diagnoses such as vocal fold nodules and muscle tension dysphonia. These speech production disorders result in effort, fatigue, pain, and even complete loss of voice. The mechanisms underlying HVDs are largely unknown. Here, the auditory-motor control of voice fundamental frequency (fo) was examined in 62 speakers with and 62 speakers without HVDs. Due to the high prevalence of HVDs in singers, and the known impacts of singing experience on auditory-motor function, groups were matched for singing experience. Speakers completed three tasks, yielding: (1) auditory discrimination of voice fo; (2) reflexive responses to sudden fo shifts; and (3) adaptive responses to sustained fo shifts. Compared to controls, and regardless of singing experience, individuals with HVDs showed: (1) worse auditory discrimination; (2) comparable reflexive responses; and (3) a greater frequency of atypical adaptive responses. Atypical adaptive responses were associated with poorer auditory discrimination, directly implicating auditory function in this motor disorder. These findings motivate a paradigm shift for understanding development and treatment of HVDs.

Highlights

Hyperfunctional voice disorders (HVDs) are the most common class of voice disorders, consisting of diagnoses such as vocal fold nodules and muscle tension dysphonia
These dysregulations of laryngeal muscle tension are accompanied by changes in vocal quality i.e., a strained and/or breathy voice3, 6, fatigue7, pain[8], and aphonia complete loss of v oice[9], which result in voice changes that interfere with communication and affect quality of life
A three-way mixed effects analysis of variance (ANOVA) demonstrated no main effect of group (HVD vs. controls; df = 1, F = 0.39, p = .53) or singing experience on reflexive responses, but there was a significant main effect of shift direction

Summary

Introduction

Hyperfunctional voice disorders (HVDs) are the most common class of voice disorders, consisting of diagnoses such as vocal fold nodules and muscle tension dysphonia. Atypical adaptive responses were associated with poorer auditory discrimination, directly implicating auditory function in this motor disorder These findings motivate a paradigm shift for understanding development and treatment of HVDs. Approximately 30% of individuals will develop a voice disorder across their lifetime[1], and hyperfunctional voice disorders (HVDs) are the most common clinical diagnosis[2]. The mechanisms underlying HVDs are still largely unknown This gap in understanding is an obstacle in determining clear d iagnostic14, 15, assessment[16, 17], and therapeutic p rotocols[18, 19], and often results in a diagnosis of exclusion (i.e., individuals receive a HVD diagnosis if there are no other clear structural or neurological reasons for the voice changes[20]). Sustained, predictable shifts in auditory fo feedback yield ‘adaptive’ responses, which demonstrate whether the feedforward system has incorporated corrections and updated subsequent vocal motor plans (auditory-motor integration[25, 32])

Objectives

Results

Conclusion