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Juha Tapio Silvola - One of the best experts on this subject based on the ideXlab platform.
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Consonant and vowel confusions in well performing children and adolescents with cochlear implants measured by a nonsense syllable repetition test
Frontiers in Psychology, 2019Co-Authors: Arne Kirkhorn Rodvik, Ole Tvete, Janne Von Koss Torkildsen, Ona Bo Wie, Ingebjorg Skaug, Juha Tapio SilvolaAbstract:Although the majority of early implanted, profoundly deaf children with cochlear implants (CIs), will develop correct pronunciation if they receive adequate oral language stimulation, many of them have difficulties with perceiving minute details of speech. The main aim of this study is to measure the confusion of Consonants and vowels in well-performing children and adolescents with CIs. The study also aims to investigate how age at onset of severe to profound deafness influences perception. The participants are 36 children and adolescents with CIs (18 girls), with a mean (SD) age of 11.6 (3.0) years (range: 5.9–16.0 years). Twenty-nine of them are prelingually deaf and 7 are postlingually deaf. Two reference groups of normal-hearing (NH) 6- and 13-year-olds are included. Consonant and vowel perception is measured by repetition of 16 bisyllabic vowel-Consonant-vowel nonsense words and 9 monosyllabic Consonant-vowel-Consonant nonsense words in an open-set design. For the participants with CIs, Consonants were mostly confused with Consonants with the same voicing and manner, and the mean (SD) voiced Consonant repetition score, 63.9 (10.6)%, was considerably lower than the mean (SD) unvoiced Consonant score, 76.9 (9.3)%. There was a devoicing bias for the stops; unvoiced stops were confused with other unvoiced stops and not with voiced stops, and voiced stops were confused with both unvoiced stops and other voiced stops. The mean (SD) vowel repetition score was 85.2 (10.6)% and there was a bias in the confusions of [iː] and [yː]; [yː] was perceived as [iː] twice as often as [yː] was repeated correctly. Subgroup analyses showed no statistically significant differences between the Consonant scores for pre- and postlingually deaf participants. For the NH participants, the Consonant repetition scores were substantially higher and the difference between voiced and unvoiced Consonant repetition scores considerably lower than for the participants with CIs. The participants with CIs obtained scores close to ceiling on vowels and real-word monosyllables, but their perception was substantially lower for voiced Consonants. This ¬may partly be related to limitations in the CI technology for the transmission of low-frequency sounds, such as insertion depth of the electrode and ability to convey temporal information.
P. Birkholz - One of the best experts on this subject based on the ideXlab platform.
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Modeling Consonant-Vowel Coarticulation for Articulatory Speech Synthesis
PLoS ONE, 2013Co-Authors: P. BirkholzAbstract:A central challenge for articulatory speech synthesis is the simulation of realistic articulatory movements, which is critical for the generation of highly natural and intelligible speech. This includes modeling coarticulation, i.e., the context-dependent variation of the articulatory and acoustic realization of phonemes, especially of Consonants. Here we propose a method to simulate the context-sensitive articulation of Consonants in Consonant-vowel syllables. To achieve this, the vocal tract target shape of a Consonant in the context of a given vowel is derived as the weighted average of three measured and acoustically-optimized reference vocal tract shapes for that Consonant in the context of the corner vowels /a/, /i/, and /u/. The weights are determined by mapping the target shape of the given context vowel into the vowel subspace spanned by the corner vowels. The model was applied for the synthesis of Consonant-vowel syllables with the Consonants /b/, /d/, /g/, /l/, /r/, /m/, /n/ in all combinations with the eight long German vowels. In a perception test, the mean recognition rate for the Consonants in the isolated syllables was 82.4%. This demonstrates the potential of the approach for highly intelligible articulatory speech synthesis.
Drs Mildred Bailey - One of the best experts on this subject based on the ideXlab platform.
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Spelling Progress Bulletin Spelling Irregularity, Spelling Reform, and Learning to Read Meaningfully, a Commentary
2020Co-Authors: Harvie Barnard Emmett, A Betts, Helen Bisgard, Wilbur J Kupfrian, William J Reed, Ben D Wood, A Emmett, Organizer Betts, Prof Emeritus, Drs Mildred BaileyAbstract:Purposes: 1. To promote continued research on the writing system (orthography) and word perception in reading. 2. To translate research for effective instruction in classroom situations. Topics include: perceptual learning, factors in word perception; relationships between intonation and perception, between phonic rules and word perception, between perception and other facets of reading; phonemic and morphemic bases of spellings; methodology. Dr. John Downing (Editor) announces a new national bilingual journal devoted to reading. It is called Reading-CanadaLecture, and is a refereed quarterly journal which aims to improve communication between educators within Canada and between Canadians and colleagues in other countries. R-C-L also will provide a forum between English speaking and French speaking educators whose mutual concern is the improvement of reading instruction in these two languages. We envisage that R-C-L will be read mainly by classroom teachers, but that there will be other readers such as school administrators, consultants, parents, university faculty members, etc. R-C-L will be open to all points of view regarding reading theory and practice. Articles will relate to all levels: pre-school, elementary, secondary, college and adult. We are currently particularly interested in receiving manuscripts on themes of practical concern to classroom teachers and clinicians. Articles will be published in full in the original language of the author, either English or French. In addition there will be a summary in the other language. R-C-L welcomes articles in either English or French from authors in any country in the world. The fluent reading process, according to current psycholinguistic theory (Goodman 1967, Smith 1973, involves less emphasis on graphic-visual characteristics and more emphasis on semantics and text structure. Furthermore, much research is currently being generated to demonstrate that reading involves an interaction of the various levels of language and the background knowledge of the reader in constructing meaning (Center for the Study of Reading [1]). Thus, the focus of reading instruction must be on comprehension. However, the beginning reader must learn to crack the orthographic code as part of (but not as the essence of) learning to read. [2] Yet, beginning reading would involve more spelling-sound relationships than would fluent reading (Shuy 1977). In considering spelling reform, two questions need to be answered: (1) Is the English spelling system the most "optimal" for learning to read? (2) Is spelling reform the only step toward literacy improvement? In other words, until spelling reform is achieved, how can teachers facilitate reading of traditional orthography? Chomsky (1973) claimed that the English writing system is predictable because it captures the abstract underlying phonological structure of words as well as the meaningful relationships among related words: Thus, the silent g of malign is related to the pronounced g in malignant. Likewise, the schwa sound of o in composition is related to the o in compose. The orthography preserves the meaningful relationships of these words as an assistance to the fluent reader who focuses on meaning rather than on phonetic details: While many sets of words follow predictable phonological alternations, some experimental evidence has questioned the psychological reality of some of the phonological processes claimed by Chomsky and Halle (1968). (See Steinberg (1973) and Ohala (1974).) Furthermore, many of the elements of traditional orthography have little psychological basis, as they were the result of linguistic and cultural history (Barnitz 1980). [3] Thus, English spelling is certainly not as optimal as originally claimed in Chomsky and Halle (1968). Would a more direct phonemic alphabet facilitate learning to read? Cross-cultural and crosslinguistic research suggests that the regularity of fit between phonological systems and writing systems facilitates, learning to decode spelling into sound as part of beginning reading (Downing 1973, Barnitz 1978. Furthermore, evidence from research on transitional writing systems suggests the role of regularity in learning to read (Downing 1965, Gleitman and Rozin 1973) However, an overemphasis on decoding is not the essence of reading (Goodman 1967). Yet, regularity of writing systems does greatly help the reading learning process. The second major question will be answered briefly. Until total spelling reform occurs -despite the many resistances (c.f. Stubbs 1980) -children still need to be taught the meaningful reading process, regardless of the orthography. For decoding is only a small part of the learning to read process. Goodman 1967, Shafer 1979. As traditional orthography still survives, how can teachers circumvent the problems of "irregularity." Here are only a few suggestions: (1) Emphasize the total language-meaning relationships in reading instruction. This can be done, for example, by using the Language Experience Approach (Stouffer 1980, Veatch et al. 1979. (See also the many reports from the Center for the Study of Reading). (2) Develop word attack skills within the context of meaningful comprehension. (3) Using natural language, provide as much regularity as possible in teaching beginning reading. Begin with regularities, then move to irregularities (Bloomfield 1942), but emphasize the total reading process. (4) As the meaningful relationships among many words are preserved in traditional orthography (malign-malignant), some aspects of these may be introduced for older readers. However, not all relationships have psychological reality. Instructional research is needed here. These suggestions alone will not solve all the literacy problems. Of course, spelling reform will be of assistance. However, until and even after spelling reform does occur, teachers must emphasize meaning in reading instruction. Footnotes Justification There appear to be two justifications of this study. First, studies of the phonetic pronunciation of word elements at each reader level provide the basis for determining the point at which certain phonetic elements may be introduced for systematic study. Second, studies of phonetic structure may provide s basis for deriving readability formulae. Two current reviews of readability studies indicate that this element is not a part of any such formula now available [9; 14]. Limitations The words analyzed were taken from a single vocabulary study The syllable was the unit used for analysis. Both initial and final Consonant phonograms were analyzed and tabulated. Syllabication and respellings for pronunciation were based on Webster's New International Dictionary Definitions Terminology used in this study is defined as follows: In 1950, Oaks reported "A Study of the Vowel Situations in a Primary (1) "short" vowel principle in closed syllables (2) "long" vowel principle in syllables ending with a final e (3) "long" (single) vowel principle in open accented syllables Oaks concluded that the recognition of vowel digraphs should be systematically taught at the primary level for two reasons: (1) there are several types of digraphs, and (2) two letters frequently represent diphthongs. Among the indirectly related studies are those of Spache [28], Dolch [16; Summary: The studies reviewed emphasized the unphonetic character of our language. Many different sounds were found for one phonogram. Some were found to have as many as eleven pronunciations Procedure The vocabulary used for this study was taken from the Betts' Primary Reading Vocabulary Studies The analysis of the vocabulary entailed the following steps. First, words were listed by reader level, and the pronunciation of each Consonant phonogram was recorded. Second, the position of the Consonant phonogram in the syllable, whether initial or final, was then tabulated. All tabulations were made in terms of the syllable in the word. Third, from these data were obtained the incidence of Consonant letters, digraphs, trigraphs, blends, and other Consonant situations. (1) A total of 1,573 single letter Consonants, 38.7% of the Consonant situations, appeared in the initial parts of the syllables. (2) A total of 1,203 single letter Consonants, 29.6% of the Consonant situations, appeared in the final parts of the syllables. (3) Single letter Consonants appeared at all reader levels in both initial and final parts of the syllables. b. Of the Consonant situations in the study, 396, or 9.8% of all Consonant situations, were Consonant digraphs. Summary of Results (1) The number of Consonant digraphs introduced in the initial parts of the syllables was 122, or 3% of the Consonant situations. (2) The number of Consonant digraphs introduced in the final parts of the syllables was 274, or 68% of the Consonant situations. (3) Consonant digraphs appeared at all reader levels in both initial and final positions in the syllables, c. There were twenty-six Consonant trigraphs, comprising .6% of the Consonant situations, identified in the vocabulary. (1) All trigraphs appeared in the final parts of the syllables. (2) Trigraphs were introduced at first-reader level and were used at all succeeding levels. d. Consonant blends were classified as two and three-letter blends. There were 613 two-letter blends, comprising 15% of the Consonant situations, in the study. Totalling 53, the three-letter blends accounted for only 1.3% of the Consonant situations. (1) A total of 336 two-letter blends, 8.2% of the Consonant situations, was used in the initial parts of the syllables. Only thirty-two three-letter blends, comprising .8% of the total Consonant situations, were used in initial positions. (2) There were 277 two-letter blends, or 6.8% of all Consonant situations in the study, in the final parts of the syllables. Twenty-one three-letter blends were tabulated in the final parts of the syllables. This was only .5% of all Consonant situations. (3) Two-letter blends were identified at all reader levels, three-letter blends appeared at first-reader level and were used at all succeeding levels. e. In this study, 130 syllabic Consonants and 16 syllabic blends were identified. The syllabic Consonants comprised 3.3%, and the syllabic blends .4% of the total Consonant situations. (1) Syllabic Consonants and syllabic blends s appeared only in final syllables of words. (2) Syllabic Consonants appeared at all levels; syllabic blends were introduced at firstreader level and used at all succeeding levels, f. In the "miscellaneous" situations classification, there were 52 Consonant situations. (1) One "miscellaneous" phonogram, ear [3] as in earth, appeared three times in the initial syllable or parts of syllables. This total comprised .1% of the total situations. (2) Thirty, .8% of the total Consonant situations, appeared in the medial parts of syllables. (3) Nineteen, .5% of the total Consonant situations, appeared in final positions in the syllables. (4) "Miscellaneous" phonograms appeared in initial positions at second-reader level, and in medial and final positions at all reader levels. 2. Of the Consonant and vowel-colored r situations analyzed in this study, 606 involved letter r. These accounted for 14.9% of all Consonant situations tabulated. a. A total of 264 letter r phonograms, 6.5% of all Consonant situations, appeared in initial syllabic positions. b. Thirty vowel-colored r [3] situations (e.g., bird), comprising .7% of the total Consonant situations, appeared in medial positions. c. There were 310 letter r situations, 7.7% of all Consonant situations in the vocabulary, identified in final parts of syllables. d. Letter r situations appeared at all reader levels encompassed by this study. 3. There were 281 Consonant phonograms, 6.9% of the total Consonant situations, containing silent letters. a. A total of 74 Consonant situations, appearing in the initial parts of the syllables, contained silent letters. This was 1.9% of the total Consonant situations. b. There were 207 Consonant phonograms, 5% of all Consonant situations appearing in the study, involving silent-letter situations which appeared in final positions
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Spelling Progress Bulletin 2. Spelling Irregularity, Spelling Reform, and Learning to Read Meaningfully, a Commentary
2020Co-Authors: Harvie Barnard Emmett, A Betts, Helen Bisgard, Wilbur J Kupfrian, William J Reed, Ben D Wood, A Emmett, Organizer Betts, Prof Emeritus, Drs Mildred BaileyAbstract:Purposes: 1. To promote continued research on the writing system (orthography) and word perception in reading. 2. To translate research for effective instruction in classroom situations. Topics include: perceptual learning, factors in word perception; relationships between intonation and perception, between phonic rules and word perception, between perception and other facets of reading; phonemic and morphemic bases of spellings; methodology. Dr. John Downing (Editor) announces a new national bilingual journal devoted to reading. It is called Reading-CanadaLecture, and is a refereed quarterly journal which aims to improve communication between educators within Canada and between Canadians and colleagues in other countries. R-C-L also will provide a forum between English speaking and French speaking educators whose mutual concern is the improvement of reading instruction in these two languages. We envisage that R-C-L will be read mainly by classroom teachers, but that there will be other readers such as school administrators, consultants, parents, university faculty members, etc. R-C-L will be open to all points of view regarding reading theory and practice. Articles will relate to all levels: pre-school, elementary, secondary, college and adult. We are currently particularly interested in receiving manuscripts on themes of practical concern to classroom teachers and clinicians. Articles will be published in full in the original language of the author, either English or French. In addition there will be a summary in the other language. R-C-L welcomes articles in either English or French from authors in any country in the world. The fluent reading process, according to current psycholinguistic theory (Goodman 1967, Smith 1973, involves less emphasis on graphic-visual characteristics and more emphasis on semantics and text structure. Furthermore, much research is currently being generated to demonstrate that reading involves an interaction of the various levels of language and the background knowledge of the reader in constructing meaning (Center for the Study of Reading [1]). Thus, the focus of reading instruction must be on comprehension. However, the beginning reader must learn to crack the orthographic code as part of (but not as the essence of) learning to read. [2] Yet, beginning reading would involve more spelling-sound relationships than would fluent reading (Shuy 1977). In considering spelling reform, two questions need to be answered: (1) Is the English spelling system the most "optimal" for learning to read? (2) Is spelling reform the only step toward literacy improvement? In other words, until spelling reform is achieved, how can teachers facilitate reading of traditional orthography? Chomsky (1973) claimed that the English writing system is predictable because it captures the abstract underlying phonological structure of words as well as the meaningful relationships among related words: Thus, the silent g of malign is related to the pronounced g in malignant. Likewise, the schwa sound of o in composition is related to the o in compose. The orthography preserves the meaningful relationships of these words as an assistance to the fluent reader who focuses on meaning rather than on phonetic details: While many sets of words follow predictable phonological alternations, some experimental evidence has questioned the psychological reality of some of the phonological processes claimed by Chomsky and Halle (1968). (See Steinberg (1973) and Ohala (1974).) Furthermore, many of the elements of traditional orthography have little psychological basis, as they were the result of linguistic and cultural history (Barnitz 1980). [3] Thus, English spelling is certainly not as optimal as originally claimed in Chomsky and Halle (1968). Would a more direct phonemic alphabet facilitate learning to read? Cross-cultural and crosslinguistic research suggests that the regularity of fit between phonological systems and writing systems facilitates, learning to decode spelling into sound as part of beginning reading (Downing 1973, Barnitz 1978. Furthermore, evidence from research on transitional writing systems suggests the role of regularity in learning to read (Downing 1965, Gleitman and Rozin 1973) However, an overemphasis on decoding is not the essence of reading (Goodman 1967). Yet, regularity of writing systems does greatly help the reading learning process. The second major question will be answered briefly. Until total spelling reform occurs -despite the many resistances (c.f. Stubbs 1980) -children still need to be taught the meaningful reading process, regardless of the orthography. For decoding is only a small part of the learning to read process. Goodman 1967, Shafer 1979. As traditional orthography still survives, how can teachers circumvent the problems of "irregularity." Here are only a few suggestions: (1) Emphasize the total language-meaning relationships in reading instruction. This can be done, for example, by using the Language Experience Approach (Stouffer 1980, Veatch et al. 1979. (See also the many reports from the Center for the Study of Reading). (2) Develop word attack skills within the context of meaningful comprehension. (3) Using natural language, provide as much regularity as possible in teaching beginning reading. Begin with regularities, then move to irregularities (Bloomfield 1942), but emphasize the total reading process. (4) As the meaningful relationships among many words are preserved in traditional orthography (malign-malignant), some aspects of these may be introduced for older readers. However, not all relationships have psychological reality. Instructional research is needed here. These suggestions alone will not solve all the literacy problems. Of course, spelling reform will be of assistance. However, until and even after spelling reform does occur, teachers must emphasize meaning in reading instruction. Footnotes Justification There appear to be two justifications of this study. First, studies of the phonetic pronunciation of word elements at each reader level provide the basis for determining the point at which certain phonetic elements may be introduced for systematic study. Second, studies of phonetic structure may provide s basis for deriving readability formulae. Two current reviews of readability studies indicate that this element is not a part of any such formula now available [9; 14]. Limitations The words analyzed were taken from a single vocabulary study [8]. These appeared in at least ten of the fourteen different aeries of basal readers. Only base forms and compound words were selected for analysis [8]. Reader levels studies ranged from primer through third. The syllable was the unit used for analysis. Both initial and final Consonant phonograms were analyzed and tabulated. Syllabication and respellings for pronunciation were based on Webster's New International Dictionary Definitions Terminology used in this study is defined as follows: In 1950, Oaks reported "A Study of the Vowel Situations in a Primary (1) "short" vowel principle in closed syllables (2) "long" vowel principle in syllables ending with a final e (3) "long" (single) vowel principle in open accented syllables Oaks concluded that the recognition of vowel digraphs should be systematically taught at the primary level for two reasons: (1) there are several types of digraphs, and (2) two letters frequently represent diphthongs. Among the indirectly related studies are those of Spache [28], Dolch [16; Summary: The studies reviewed emphasized the unphonetic character of our language. Many different sounds were found for one phonogram. Some were found to have as many as eleven pronunciations Procedure The vocabulary used for this study was taken from the Betts' Primary Reading Vocabulary Studies [9], used also by Oaks in A Study of the Vowel Situation in a Primary Reading Vocabulary The analysis of the vocabulary entailed the following steps. First, words were listed by reader level, and the pronunciation of each Consonant phonogram was recorded. Second, the position of the Consonant phonogram in the syllable, whether initial or final, was then tabulated. All tabulations were made in terms of the syllable in the word. Third, from these data were obtained the incidence of Consonant letters, digraphs, trigraphs, blends, and other Consonant situations. (1) A total of 1,573 single letter Consonants, 38.7% of the Consonant situations, appeared in the initial parts of the syllables. (2) A total of 1,203 single letter Consonants, 29.6% of the Consonant situations, appeared in the final parts of the syllables. (3) Single letter Consonants appeared at all reader levels in both initial and final parts of the syllables. b. Of the Consonant situations in the study, 396, or 9.8% of all Consonant situations, were Consonant digraphs. Summary of Results (1) The number of Consonant digraphs introduced in the initial parts of the syllables was 122, or 3% of the Consonant situations. (2) The number of Consonant digraphs introduced in the final parts of the syllables was 274, or 68% of the Consonant situations. (3) Consonant digraphs appeared at all reader levels in both initial and final positions in the syllables, c. There were twenty-six Consonant trigraphs, comprising .6% of the Consonant situations, identified in the vocabulary. (1) All trigraphs appeared in the final parts of the syllables. (2) Trigraphs were introduced at first-reader level and were used at all succeeding levels. d. Consonant blends were classified as two and three-letter blends. There were 613 two-letter blends, comprising 15% of the Consonant situations, in the study. Totalling 53, the three-letter blends accounted for only 1.3% of the Consonant situations. (1) A total of 336 two-letter blends, 8.2% of the Consonant situations, was used in the initial parts of the syllables. Only thirty-two three-letter blends, comprising .8% of the total Consonant situations, were used in initial positions. (2) There were 277 two-letter blends, or 6.8% of all Consonant situations in the study, in the final parts of the syllables. Twenty-one three-letter blends were tabulated in the final parts of the syllables. This was only .5% of all Consonant situations. (3) Two-letter blends were identified at all reader levels, three-letter blends appeared at first-reader level and were used at all succeeding levels. e. In this study, 130 syllabic Consonants and 16 syllabic blends were identified. The syllabic Consonants comprised 3.3%, and the syllabic blends .4% of the total Consonant situations. (1) Syllabic Consonants and syllabic blends s appeared only in final syllables of words. (2) Syllabic Consonants appeared at all levels; syllabic blends were introduced at firstreader level and used at all succeeding levels, f. In the "miscellaneous" situations classification, there were 52 Consonant situations. (1) One "miscellaneous" phonogram, ear [3] as in earth, appeared three times in the initial syllable or parts of syllables. This total comprised .1% of the total situations. (2) Thirty, .8% of the total Consonant situations, appeared in the medial parts of syllables. (3) Nineteen, .5% of the total Consonant situations, appeared in final positions in the syllables. (4) "Miscellaneous" phonograms appeared in initial positions at second-reader level, and in medial and final positions at all reader levels. 2. Of the Consonant and vowel-colored r situations analyzed in this study, 606 involved letter r. These accounted for 14.9% of all Consonant situations tabulated. a. A total of 264 letter r phonograms, 6.5% of all Consonant situations, appeared in initial syllabic positions. b. Thirty vowel-colored r [3] situations (e.g., bird), comprising .7% of the total Consonant situations, appeared in medial positions. c. There were 310 letter r situations, 7.7% of all Consonant situations in the vocabulary, identified in final parts of syllables. d. Letter r situations appeared at all reader levels encompassed by this study. 3. There were 281 Consonant phonograms, 6.9% of the total Consonant situations, containing silent letters. a. A total of 74 Consonant situations, appearing in the initial parts of the syllables, contained silent letters. This was 1.9% of the total Consonant situations. b. There were 207 Consonant phonograms, 5% of all Consonant situations appearing in the study, involving silent-letter situations which appeared in final positions
Michael F Dorman - One of the best experts on this subject based on the ideXlab platform.
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the effect of parametric variations of cochlear implant processors on speech understanding
Journal of the Acoustical Society of America, 2000Co-Authors: Oguz Poroy, Michael F DormanAbstract:This study investigated the effect of five speech processing parameters, currently employed in cochlear implant processors, on speech understanding. Experiment 1 examined speech recognition as a function of stimulation rate in six Med-El/CIS-Link cochlear implant listeners. Results showed that higher stimulation rates (2100 pulses/s) produced a significantly higher performance on word and Consonant recognition than lower stimulation rates (<800 pulses/s). The effect of stimulation rate on Consonant recognition was highly dependent on the vowel context. The largest benefit was noted for Consonants in the /uCu/ and /iCi/ contexts, while the smallest benefit was noted for Consonants in the /aCa/ context. This finding suggests that the /aCa/ Consonant test, which is widely used today, is not sensitive enough to parametric variations of implant processors. Experiment 2 examined vowel and Consonant recognition as a function of pulse width for low-rate (400 and 800 pps) implementations of the CIS strategy. For t...
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the effect of parametric variations of cochlear implant processors on speech understanding
Journal of the Acoustical Society of America, 2000Co-Authors: Philipos C Loizou, Oguz Poroy, Michael F DormanAbstract:This study investigated the effect of five speech processing parameters, currently employed in cochlear implant processors, on speech understanding. Experiment 1 examined speech recognition as a function of stimulation rate in six Med-El/CIS-Link cochlear implant listeners. Results showed that higher stimulation rates (2100 pulses/s) produced a significantly higher performance on word and Consonant recognition than lower stimulation rates (<800 pulses/s). The effect of stimulation rate on Consonant recognition was highly dependent on the vowel context. The largest benefit was noted for Consonants in the /uCu/ and /iCi/ contexts, while the smallest benefit was noted for Consonants in the /aCa/ context. This finding suggests that the /aCa/ Consonant test, which is widely used today, is not sensitive enough to parametric variations of implant processors. Experiment 2 examined vowel and Consonant recognition as a function of pulse width for low-rate (400 and 800 pps) implementations of the CIS strategy. For the 400-pps condition, wider pulse widths (208 μs/phase) produced significantly higher performance on Consonant recognition than shorter pulse widths (40 μs/phase). Experiments 3–5 examined vowel and Consonant recognition as a function of the filter overlap in the analysis filters, shape of the amplitude mapping function, and signal bandwidth. Results showed that the amount of filter overlap (ranging from −20 to −60 dB/oct) and the signal bandwidth (ranging from 6.7 to 9.9 kHz) had no effect on phoneme recognition. The shape of the amplitude mapping functions (ranging from strongly compressive to weakly compressive) had only a minor effect on performance, with the lowest performance obtained for nearly linear mapping functions. Of the five speech processing parameters examined in this study, the pulse rate and the pulse width had the largest (positive) effect on speech recognition. For a fixed pulse width, higher rates (2100 pps) of stimulation provided a significantly better performance on word recognition than lower rates (<800 pps) of stimulation. High performance was also achieved by jointly varying the pulse rate and pulse width. The above results indicate that audiologists can optimize the implant listener’s performance either by increasing the pulse rate or by jointly varying the pulse rate and pulse width.
Arne Kirkhorn Rodvik - One of the best experts on this subject based on the ideXlab platform.
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Consonant and vowel confusions in well performing children and adolescents with cochlear implants measured by a nonsense syllable repetition test
Frontiers in Psychology, 2019Co-Authors: Arne Kirkhorn Rodvik, Ole Tvete, Janne Von Koss Torkildsen, Ona Bo Wie, Ingebjorg Skaug, Juha Tapio SilvolaAbstract:Although the majority of early implanted, profoundly deaf children with cochlear implants (CIs), will develop correct pronunciation if they receive adequate oral language stimulation, many of them have difficulties with perceiving minute details of speech. The main aim of this study is to measure the confusion of Consonants and vowels in well-performing children and adolescents with CIs. The study also aims to investigate how age at onset of severe to profound deafness influences perception. The participants are 36 children and adolescents with CIs (18 girls), with a mean (SD) age of 11.6 (3.0) years (range: 5.9–16.0 years). Twenty-nine of them are prelingually deaf and 7 are postlingually deaf. Two reference groups of normal-hearing (NH) 6- and 13-year-olds are included. Consonant and vowel perception is measured by repetition of 16 bisyllabic vowel-Consonant-vowel nonsense words and 9 monosyllabic Consonant-vowel-Consonant nonsense words in an open-set design. For the participants with CIs, Consonants were mostly confused with Consonants with the same voicing and manner, and the mean (SD) voiced Consonant repetition score, 63.9 (10.6)%, was considerably lower than the mean (SD) unvoiced Consonant score, 76.9 (9.3)%. There was a devoicing bias for the stops; unvoiced stops were confused with other unvoiced stops and not with voiced stops, and voiced stops were confused with both unvoiced stops and other voiced stops. The mean (SD) vowel repetition score was 85.2 (10.6)% and there was a bias in the confusions of [iː] and [yː]; [yː] was perceived as [iː] twice as often as [yː] was repeated correctly. Subgroup analyses showed no statistically significant differences between the Consonant scores for pre- and postlingually deaf participants. For the NH participants, the Consonant repetition scores were substantially higher and the difference between voiced and unvoiced Consonant repetition scores considerably lower than for the participants with CIs. The participants with CIs obtained scores close to ceiling on vowels and real-word monosyllables, but their perception was substantially lower for voiced Consonants. This ¬may partly be related to limitations in the CI technology for the transmission of low-frequency sounds, such as insertion depth of the electrode and ability to convey temporal information.
