Analysis of Articulation Error Patterns Depending on the Level of Speech Intelligibility in Adults with Dysarthria

Lee, Young Mee; Sung, Jee Eun; Sim, Hyun Sub; Han, Ji Hoo; Song, Han Nae

ORIGINAL ARTICLE

Commun Sci Disord. 2012;17(1): 130-142.

Young Mee Lee^` , Jee Eun Sung^` , Hyun Sub Sim^` , Ji Hoo Han^` , and Han Nae Song^`

이영미(Young Mee Lee)| 성지은(Jee Eun Sung)| 심현섭(Hyun Sub Sim)| 한지후(Ji Hoo Han)| 송한내(Han Nae Song)

ABSTRACT

Background & Objectives
The purpose of the current study was to investigate the articulation error patterns according to the level of speech intelligibility and to examine which articulation error patterns significantly predicted speech intelligibility in adults with dysarthria.
Methods
One hundred speakers with dysarthria and 25 native listeners participated in the present study. Based on the levels of speech intelligibility, speakers were classified into three groups: highintelligibility speakers (n=44), mid-intelligibility speakers (n=33), and low-intelligibility speakers (n=23). APAC words were used as stimuli for obtaining dysarthric speech. Articulation error patterns were classified into eight categories as follows: omission, substitution, distortion, addition of consonants, prolongation, repetition of the phonemes and syllables, intra-word pause, and non-speech sounds. Frequencies of articulation error patterns were examined by speech-language pathologists. Speech intelligibility was judged by 25 native listeners using a word transcription task.
Results
Results of the two-way ANOVA (groups x articulation error patterns) revealed that the two main effects were statistically significant, indicating that high-intelligibility speakers showed fewer errors than the rest of the groups, and that substitution had a significantly higher frequency for error than the rest of the patterns. A two-way interaction was statistically significant due to the fact that the group differences emerged only in three articulation error patterns (substitution, omission, and intra-word pause). A stepwise multiple regressions analysis showed that omission, substitution, and nonspeech sounds were significant predictors of speech intelligibility in dysarthria.
Discussion & Conclusion
The current study suggested that the articulation error pattern varied depending on the level of speech intelligibility and may differentially contribute to speech intelligibility in persons with dysarthria. The clinical implications of the results are discussed in terms of evaluating dysarthric speech and developing a speech recognition device for dysarthric speakers.