Frequency of consonant articulation errors in dysarthric speech

This paper analyses consonant articulation errors in dysarthric speech produced by seven American-English native speakers with cerebral palsy. Twenty-three consonant phonemes were transcribed with diacritics as necessary in order to represent non-phoneme misarticulations. Error frequencies were examined with respect to six variables: articulatory complexity, place of articulation, and manner of articulation of the target phoneme; and change in articulatory complexity, place, and manner resulting from the misarticulation. Results showed that target phonemes with high articulatory complexity were most often misarticulated, independent of intelligibility, but low-intelligibility speakers reduced the complexity of target consonants more frequently. All speakers tended to misarticulate to the adjacent place of the target place, but this pattern was most prominent for high-intelligibility speakers. Low- and mid-intelligibility speakers produced more manner errors than high-intelligibility speakers. Based on these results, a two-part model of consonant articulation errors is proposed for CP-associated spastic dysarthia.