Vowels and Consonants: The Relative Effect of Speech Sound Errors on Intelligibility (original) (raw)
Related papers
Cortex, 2002
We present the case of two aphasic patients: one with fluent speech, MM, and one with dysfluent speech, DB. Both patients make similar proportions of phonological errors in speech production and the errors have similar characteristics. A closer analysis, however, shows a number of differences. DB's phonological errors involve, for the most part, simplifications of syllabic structure; they affect consonants more than vowels; and, among vowels, they show effects of sonority/complexity. This error pattern may reflect articulatory difficulties. MM's errors, instead, show little effect of syllable structure, affect vowels at least as much as consonants and, and affect all different vowels to a similar extent. This pattern is consistent with a more central impairment involving the selection of the right phoneme among competing alternatives. We propose that, at this level, vowel selection may be more difficult than consonant selection because vowels belong to a smaller set of repeatedly activated units.
Speech Error Evidence on the Role of the Vowel in Syllable Structure
2011
s Speakers produced errors on vowels less often than on consonants, and on nuclei less often than on codas. s Rates of errors on CV and VC pairs were above chance s Errors on Vs most often occur with errors on at least one contiguous C, but not vice versa. s The Articulatory Phonology model of syllable structure, with the additional feature of sequential activation, would best predict these observed asymmetries.
Ranking severity of speech errors by their phonological impact in context
Interspeech 2014, 2014
Children with speech disorders often present with systematic speech error patterns. In clinical assessments of speech disorders, evaluating the severity of the disorder is central. Current measures of severity have limited sensitivity to factors like the frequency of the target sounds in the child's language and the degree of phonological diversity, which are factors that can be assumed to affect intelligibility. By constructing phonological filters to simulate eight speech error patterns often observed in children, and applying these filters to a phonologically transcribed corpus of 350K words, this study explores three quantitative measures of phonological impact: Percentage of Consonants Correct (PCC), edit distance, and degree of homonymy. These metrics were related to estimated ratings of severity collected from 34 practicing clinicians. The results show an expected high correlation between the PCC and edit distance metrics, but that none of the three metrics align with clinicians' ratings. Although these results do not generate definite answers to what phonological factors contribute the most to (un)intelligibility, this study demonstrates a methodology that allows for large-scale investigations of the interplay between phonological errors and their impact on speech in context, within and across languages.
Child Language Teaching and Therapy, 2012
Compared to the treatment of consonant segments, the treatment of vowels is infrequently described in the literature on children's speech difficulties. Vowel difficulties occur less frequently than those with consonants but may have significant impact on intelligibility. In order to evaluate the effectiveness of vowel targeted intervention (VTI) with two 10-year-old children with severe and persisting speech difficulties measures of (a) percentage vowels correct and (b) intelligibility outcomes by peer group listeners were used. Assessment of vowel production was used to design and carry out intervention for each child, the success of which was measured in two ways: comparing (a) percentage of vowels correct before and after the intervention, (b) the percentage of pre-vs. post-intervention utterances understood by a group of typical peer listeners (aged 9 to 11 years). Pre-and post-intervention speech samples (comprising single words, imitated sentences and spontaneous speech) were edited onto a CD for these listeners, who were asked to write down what had been said. The two children with speech difficulties made significant improvement in vowel production as measured by the percentage of vowels correct. The listeners perceived more productions accurately post-intervention than pre-intervention. There was also a reduction in the range of the listeners' misperceptions of target words. VTI was effective in terms of both increasing PVC and intelligibility outcomes as judged by peer group listeners. It is not more complicated to carry out VTI than consonant targeted intervention; this should be considered more often when planning therapy for children where vowels are affected.
Many English language instructors are reluctant to incorporate pronunciation instruction into their teaching curriculum (Thomson 2014). One reason for such reluctance is that L2 pronunciation errors are numerous, and there is not enough time for teachers to address all of them (Munro and Derwing 2006; Thomson 2014). The current study aims to help language teachers set priorities for their instruction by identifying the segmental and structural aspects of pronunciation that are most foreign-accented to native speakers of American English. The current study employed a perception experiment. 100 speech samples selected from the Speech Accent Archive (Weinberger 2016) were presented to 110 native American English listeners who listened to and rated the foreign accentedness of each sample on a 9-point rating scale. 20 of these samples portray no segmental or syllable structure L2 errors. The other 80 samples contain a single consonant, vowel, or syllable structure L2 error. The backgrounds of the speakers of these samples came from 52 different native languages. Global prosody of each sample was controlled for by comparing its F0 contour and duration to a native English sample using the Dynamic Time Warping method (Giorgino 2009). The results show that 1) L2 consonant errors in general are judged to be more accented than vowel or syllable structure errors; 2) phonological environment affects accent perception, 3) occurrences of non-English consonants always lead to higher accentedness ratings; 4) among L2 syllable errors, vowel epenthesis is judged to be as accented as consonant substitutions, while deletion is judged to be less accented or not accented at all. The current study, therefore, recommends that language instructors attend to consonant errors in L2 speech while taking into consideration their respective phonological environments.
Journal of Speech Language and Hearing Research, 2014
Purpose: Phonetic accommodation in speech errors has traditionally been used to identify the processing level at which an error has occurred. Recent studies have challenged the view that noncanonical productions may solely be due to phonetic, not phonological, processing irregularities, as previously assumed. The authors of the present study investigated the relationship between phonological and phonetic planning processes on the basis of voice onset time (VOT) behavior in consonant cluster errors. Method: Acoustic data from 22 German speakers were recorded while eliciting errors on sibilant-stop clusters. Analyses consider VOT duration as well as intensity and spectral properties of the sibilant. Results: Of all incorrect responses, 28% failed to show accommodation. Sibilant intensity and spectral properties differed from correct responses irrespective of whether VOT was accommodated. Conclusions: The data overall do not allow using (a lack of) accommodation as a diagnostic as to the processing level at which an error has occurred. The data support speech production models that allow for an integrated view of phonological and phonetic processing.
Articulation or phonology? Evidence from longitudinal error data
Clinical linguistics & phonetics, 2018
Children's speech difficulties can be motor (phone misarticulation) or linguistic (impaired knowledge of phonological contrasts and constraints). These two difficulties sometimes co-occur. This paper reports longitudinal data from the Early Language in Victoria Study (ELVS) at 4 and 7 years of age. Of 1494 participants, 93 made non-age appropriate speech errors on standardised assessments at 4 years, and were able to be reassessed at 7 years. At 4 years, 85% of these children only made phonological errors, 14% made both articulation and phonological errors and one child only made articulation errors (a lateral lisp). In total, 8 of 13 children making both articulation and phonological errors at 4 years had resolved by 7 years. Unexpectedly, eight children who had demonstrated articulation of fricatives at 4 years, acquired distorted production of ≥ 50% of occurrences of/s, z/ by 7 years. In total, then, 22 children (24% of children with speech difficulties) made articulatory err...
Speech errors across the lifespan
Language and cognitive processes, 2006
Dell, Burger and Svec (1997) proposed that the proportion of speech errors classified as anticipations (e.g., "moot and mouth") can be predicted solely from the overall error rate, such that the greater the error rate, the lower the anticipatory proportion (AP) of errors. We report a study examining whether this effect applies to changes in error rates that occur developmentally and as a result of aging. Speech errors were elicited from 8-and 11-year-old children, young adults and older adults. The error rate decreased and the AP increased from children to young adults, but neither error rate nor AP differed significantly between young and older adults. In cases where fast speech resulted in a higher error rate than slow speech, the AP was lower. Thus, there was overall support for Dell et al's prediction from speech error data across the lifespan.
Language, Speech, and Hearing Services in Schools, 2007
Purpose The purpose of this study was to examine the relationship between the types of speech errors that are produced by children with speech-sound disorders and the children’s phonological awareness skills during their prekindergarten and kindergarten years. Method Fifty-eight children with speech-sound disorders were assessed during the spring of their prekindergarten year and then again at the end of their kindergarten year. The children’s responses on the Goldman–Fristoe Test of Articulation (R. Goldman & M. Fristoe, 2000) were described in terms of match ratios for the features of each target sound and the type of error produced. Match ratios and error type frequencies were then examined as a function of the child’s performance on a test of phonological awareness. Results Lower match ratios for +distributed and higher frequencies of typical syllable structure errors and atypical segment errors were associated with poorer phonological awareness test performance. However, no asp...