A Study of Speech Intelligibility Affected by Voice Quality Degradation

Pyo, Hwa Young; Sim, Hyun Sub

ORIGINAL ARTICLE

Commun Sci Disord. 2007;12(2): 256-278.

Hwa Young Pyo^` , and Hyun Sub Sim^`

표화명(Hwa Young Pyo)| 심현섭(Hyun Sub Sim)

ABSTRACT

Background & Objectives
Many patients with voice disorders have complained of their unintelligible speech, but their speech intelligibility has been beyond the experts’ interests due to the normal phoneme production and prosody of the patients. This study investigated speech intelligibility affected by voice quality degradation in patients with voice disorders.
Methods
Lists of words and sentences were extracted from the paragraph produced by the 3 normals and 12 patients with Voice disorders. The 12 patients were further divided into 3 groups comprising 4 patients in each group according to the GRBAS scale: G1 group with mild, G2 group with moderate, and G3 group with severe severities. Then, 32 people with normal hearing wrote down the words that they heard and rated the sentences using the visual analog scale.
Results
For the word identification test, the G1 group had the highest intelligibility and the G3 group the lowest. The results of rating scales showed that, in intelligibility and overall impression, the normal group had the highest score and G3 the lowest. In listening effort and deviation of loudness, the G3 had the highest score and the normal group the lowest. Speech intelligibility had a positive correlation with overall impression and a negative correlation with listening effort and deviation of loudness.
Discussion & Conclusion
Patients with severe voice disorders showed very low intelligibility in spite of their intact articulation and prosody. This result may imply that we should put more treatment efforts in improving the intelligibility of patients with voice disorders.