Does Knowledge of Diagnosis Affect Inexperienced Listeners’ Judgments of Spasmodic Dysphonia

Document Type


Conference Title/Conference Publication

43rd Annual Voice Foundation Symposium


The Voice Foundation


Philadelphia, PA

Conference Dates

May 28, 2014 - June 1, 2014

Date of Presentation



Objectives: Adductor spasmodic dysphonia (ADSD) is a laryngeal dystonia characterized by an effortful voice quality in purposeful speech. Beyond changes in voice, one study showed that unfamiliar communication partners perceive ADSD speakers as significantly older, less confident, and more tearful than control speakers. To address communication breakdowns, one strategy that ADSD speakers often employ includes disclosure of their condition (i.e., I have a voice problem called spasmodic dysphonia). Yet, it is unknown whether knowledge of a diagnostic condition negatively or positively affects listeners’ perceptions about that speaker. The purpose of this study is to determine whether knowledge of diagnosis affects inexperienced listeners’ judgments of perceived effort, confidence, and tearfulness in speakers with ADSD when compared to controls.

Study Design: Experimental.

Methods: Twenty speakers with ADSD and 20 age-and sex-matched controls provided speech recordings of the Rainbow Passage. Thirty inexperienced listeners were randomly assigned to two groups. Group 1 evaluated speech samples without diagnostic information; Group 2 was provided with diagnostic information (no vocal complaints vs. voice problem called ADSD)for each speaker. Listeners evaluated speech samples for speech effort, confidence, and tearfulness using 100 mm visual analog scales.

Results: Data collection is ongoing; listeners in Group 1 have completed the task. Group means of listeners’ judgments will be calculated across conditions. A series of 2 x 2 ANOVAs will be completed to determine whether there is an effect of group (ADSD vs. control) or condition (no knowledge vs. knowledge) on listeners’ judgments. It is hypothesized that knowledge of diagnosis may bias listeners’ judgments positively for controls, and negatively for ADSD speakers (i.e., known as an expectancy effect).

Conclusions: Results will reveal whether inexperienced listeners’ judgments may be affected by knowledge of a person’s condition, as in a disclosure scenario. Results have implications for counselling individuals with ADSD.

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