Expression and Prognostic Value Identification of Methylenetetrahydrofolate Dehydrogenase 2 (MTHFD2) in Brain Low-Grade Glioma.

OBJECTIVE: This study aimed to reveal the potential function of methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) and emphasized its importance in brain low-grade glioma (LGG). METHODS: We firstly explored the differential expression of MTHFD2 mRNA in LGG and normal tissues, followed by correlation analysis of MTHFD2 mRNA expression with patient's clinical characteristics. MTHFD2 protein expression in LGG and subcellular location were also evaluated. Then, survival analysis was performed to reveal the influence of MTHFD2 expression on the overall survival of patients, and Cox regression analysis was applied to predict the prognostic factor for overall survival of LGG. Finally, we performed functional analysis to reveal potential MTHFD2-associated pathways involved in LGG. RESULTS: We found that MTHFD2 was highly expressed in LGG patients (P<0.05), and MTHFD2 expression was related to patient's age and IDH mutation status (all P<0.05). MTHFD2 protein was mainly localized to the mitochondria. Survival analysis showed that high expression of MTHFD2 desirably improved the prognosis of LGG patients (P<0.001), especially for those patients with age ≥45 years (P<0.05). But independent prognostic role of MTHFD2 in LGG was not observed. Pathway enrichment analysis indicated that MTHFD2 high expression significantly and positively participated in the pathway of one carbon pool by folate (all P<0.05). CONCLUSION: High expression of MTHFD2 was observed in LGG, which was favorable for the overall survival of LGG patients. Our results assumed that MTHFD2 high expression might play a pivotal role in LGG through positively regulating pathway of one carbon pool by folate.

Phoneme Error Pattern by Heritage Speakers of Spanish on an English Word Recognition Test.

BACKGROUND: Heritage speakers acquire their native language from home use in their early childhood. As the native language is typically a minority language in the society, these individuals receive their formal education in the majority language and eventually develop greater competency with the majority than their native language. To date, there have not been specific research attempts to understand word recognition by heritage speakers. It is not clear if and to what degree we may infer from evidence based on bilingual listeners in general. PURPOSE: This preliminary study investigated how heritage speakers of Spanish perform on an English word recognition test and analyzed their phoneme errors. RESEARCH DESIGN: A prospective, cross-sectional, observational design was employed. STUDY SAMPLE: Twelve normal-hearing adult Spanish heritage speakers (four men, eight women, 20-38 yr old) participated in the study. Their language background was obtained through the Language Experience and Proficiency Questionnaire. Nine English monolingual listeners (three men, six women, 20-41 yr old) were also included for comparison purposes. DATA COLLECTION AND ANALYSIS: Listeners were presented with 200 Northwestern University Auditory Test No. 6 words in quiet. They repeated each word orally and in writing. Their responses were scored by word, word-initial consonant, vowel, and word-final consonant. Performance was compared between groups with Student's t test or analysis of variance. Group-specific error patterns were primarily descriptive, but intergroup comparisons were made using 95% or 99% confidence intervals for proportional data. RESULTS: The two groups of listeners yielded comparable scores when their responses were examined by word, vowel, and final consonant. However, heritage speakers of Spanish misidentified significantly more word-initial consonants and had significantly more difficulty with initial /p, b, h/ than their monolingual peers. The two groups yielded similar patterns for vowel and word-final consonants, but heritage speakers made significantly fewer errors with /e/ and more errors with word-final /p, k/. CONCLUSIONS: Data reported in the present study lead to a twofold conclusion. On the one hand, normal-hearing heritage speakers of Spanish may misidentify English phonemes in patterns different from those of English monolingual listeners. Not all phoneme errors can be readily understood by comparing Spanish and English phonology, suggesting that Spanish heritage speakers differ in performance from other Spanish-English bilingual listeners. On the other hand, the absolute number of errors and the error pattern of most phonemes were comparable between English monolingual listeners and Spanish heritage speakers, suggesting that audiologists may assess word recognition in quiet in the same way for these two groups of listeners, if diagnosis is based on words, not phonemes.

Acoustic-Phonetic Versus Lexical Processing in Nonnative Listeners Differing in Their Dominant Language.

PURPOSE: Nonnative listeners have difficulty recognizing English words due to underdeveloped acoustic-phonetic and/or lexical skills. The present study used Boothroyd and Nittrouer's (1988)j factor to tease apart these two components of word recognition. METHOD: Participants included 15 native English and 29 native Russian listeners. Fourteen and 15 of the Russian listeners reported English (ED) and Russian (RD) to be their dominant language, respectively. Listeners were presented 119 consonant-vowel-consonant real and nonsense words in speech-spectrum noise at +6 dB SNR. Responses were scored for word and phoneme recognition, the logarithmic quotient of which yielded j. RESULTS: Word and phoneme recognition was comparable between native and ED listeners but poorer in RD listeners. Analysis of j indicated less effective use of lexical information in RD than in native and ED listeners. Lexical processing was strongly correlated with the length of residence in the United States. CONCLUSIONS: Language background is important for nonnative word recognition. Lexical skills can be regarded as nativelike in ED nonnative listeners. Compromised word recognition in ED listeners is unlikely a result of poor lexical processing. Performance should be interpreted with caution for listeners dominant in their first language, whose word recognition is affected by both lexical and acoustic-phonetic factors.

Relative Weighting of Semantic and Syntactic Cues in Native and Non-Native Listeners' Recognition of English Sentences.

OBJECTIVE: Non-native listeners do not recognize English sentences as effectively as native listeners, especially in noise. It is not entirely clear to what extent such group differences arise from differences in relative weight of semantic versus syntactic cues. This study quantified the use and weighting of these contextual cues via Boothroyd and Nittrouer's j and k factors. The j represents the probability of recognizing sentences with or without context, whereas the k represents the degree to which context improves recognition performance. DESIGN: Four groups of 13 normal-hearing young adult listeners participated. One group consisted of native English monolingual (EMN) listeners, whereas the other three consisted of non-native listeners contrasting in their language dominance and first language: English-dominant Russian-English, Russian-dominant Russian-English, and Spanish-dominant Spanish-English bilinguals. All listeners were presented three sets of four-word sentences: high-predictability sentences included both semantic and syntactic cues, low-predictability sentences included syntactic cues only, and zero-predictability sentences included neither semantic nor syntactic cues. Sentences were presented at 65 dB SPL binaurally in the presence of speech-spectrum noise at +3 dB SNR. Listeners orally repeated each sentence and recognition was calculated for individual words as well as the sentence as a whole. RESULTS: Comparable j values across groups for high-predictability, low-predictability, and zero-predictability sentences suggested that all listeners, native and non-native, utilized contextual cues to recognize English sentences. Analysis of the k factor indicated that non-native listeners took advantage of syntax as effectively as EMN listeners. However, only English-dominant bilinguals utilized semantics to the same extent as EMN listeners; semantics did not provide a significant benefit for the two non-English-dominant groups. When combined, semantics and syntax benefitted EMN listeners significantly more than all three non-native groups of listeners. CONCLUSIONS: Language background influenced the use and weighting of semantic and syntactic cues in a complex manner. A native language advantage existed in the effective use of both cues combined. A language-dominance effect was seen in the use of semantics. No first-language effect was present for the use of either or both cues. For all non-native listeners, syntax contributed significantly more to sentence recognition than semantics, possibly due to the fact that semantics develops more gradually than syntax in second-language acquisition. The present study provides evidence that Boothroyd and Nittrouer's j and k factors can be successfully used to quantify the effectiveness of contextual cue use in clinically relevant, linguistically diverse populations.

[Brainstem cavernous malformation and its surgical treatment].

OBJECTIVE: To analyze the clinical characteristics and surgery approach for patients with brainstem cavernous malformation (BSCM). METHODS: The clinical data of 23 BSCM patients (5 cases at midbrain, 16 cases at pons, and 2 cases at medulla) treated in the Second Affiliated Hospital Zhejiang University School of Medicine from July 2003 to June 2014 were retrospectively reviewed. The medical history, radiological findings, operation records, postoperative course and follow-up results were analyzed. RESULTS: Suboccipital approach, retrosigmoid approach, subtentorial supracerebella approach, Poppen approach, pterional approach, Kawase approach, interhemispheric transcallosal third ventrical approach were applied for the surgery of BSCM patients. Among them, Kawase approach and interhemispheric transcallosal third ventrical approach were firstly reported in treatment of BSCM. Total resection was achieved in 22 cases. Neurological function was improved in 15 cases, unchanged in 7 cases and deteriorated in 1 case. Fifteen cases were followed up for a mean period of 3.5 years and signs of recurrence was found. CONCLUSION: Proper selection of surgical approach is important to assure total resection of the lesions, to protect surrounding normal vital structures and to avoid post-surgical complications.

English word frequency and recognition in bilinguals: Inter-corpus comparison and error analysis.

OBJECTIVE: This study is the second of a two-part investigation on lexical effects on bilinguals' performance on a clinical English word recognition test. Focus is on word-frequency effects using counts provided by four corpora. DESIGN: Frequency of occurrence was obtained for 200 NU-6 words from the Hoosier mental lexicon (HML) and three contemporary corpora, American National Corpora, Hyperspace analogue to language (HAL), and SUBTLEX(US). Correlation analysis was performed between word frequency and error rate. STUDY SAMPLE: Ten monolinguals and 30 bilinguals participated. Bilinguals were further grouped according to their age of English acquisition and length of schooling/working in English. RESULTS: Word frequency significantly affected word recognition in bilinguals who acquired English late and had limited schooling/working in English. When making errors, bilinguals tended to replace the target word with a word of a higher frequency. Overall, the newer corpora outperformed the HML in predicting error rate. CONCLUSIONS: Frequency counts provided by contemporary corpora predict bilinguals' recognition of English monosyllabic words. Word frequency also helps explain top replacement words for misrecognized targets. Word-frequency effects are especially prominent for bilinguals foreign born and educated.

How "proficient" is proficient? Bilingual listeners' recognition of English words in noise.

PURPOSE: Shi (2011, 2013) obtained sensitivity/specificity measures of bilingual listeners' English and relative proficiency ratings as the predictor of English word recognition in quiet. The current study investigated how relative proficiency predicted word recognition in noise. METHOD: Forty-two monolingual and 168 bilingual normal-hearing listeners were included. Bilingual listeners rated their proficiency in listening, speaking, and reading in English and in the other language using an 11-point scale. Listeners were presented with 50 English monosyllabic words in quiet at 45 dB HL and in multitalker babble with a signal-to-noise ratio of +6 and 0 dB. RESULTS: Data in quiet confirmed Shi's (2013) finding that relative proficiency with or without dominance predicted well whether bilinguals performed on par with the monolingual norm. Predicting the outcome was difficult for the 2 noise conditions. To identify bilinguals whose performance fell below the normative range, dominance per se or a combination of dominance and average relative proficiency rating yielded the best sensitivity/specificity and summary measures, including Youden's index. CONCLUSION: Bilinguals' word recognition is more difficult to predict in noise than in quiet; however, proficiency and dominance variables can predict reasonably well whether bilinguals may perform at a monolingual normative level.

Acceptance noise level: effects of the speech signal, babble, and listener language.

PURPOSE: The acceptable noise level (ANL) measure has gained much research/clinical interest in recent years. The present study examined how the characteristics of the speech signal and the babble used in the measure may affect the ANL in listeners with different native languages. METHOD: Fifteen English monolingual, 16 Russian-English bilingual, and 24 Spanish-English bilingual listeners participated. The ANL was obtained in eight conditions varying in the language of the signal (English and Spanish), language of the babble (English and Spanish), and number of talkers in the babble (4 and 12). Test conditions were randomized across listeners. The ANL for each condition was based on a minimum of two trials. RESULTS: Russian-English bilinguals yielded higher ANLs than other listeners; the intergroup difference of 4-5 dB was statistically and clinically significant. Spanish signals yielded significantly higher ANLs than English signals, but this difference of 0.5 dB was clinically negligible. The language and composition of the babble had a significant effect on Russian-English bilinguals, who yielded higher ANLs with the Spanish than English 12-talker babble. CONCLUSION: The above findings do not fully support the notion that the ANL is language- and population-independent. Clinicians should be aware of possible effects on ANL measures due to listeners' linguistic/cultural background.

Speech audiometry and Spanish-English bilinguals: challenges in clinical practice.

PURPOSE: The Spanish-English bilingual population has been on a steady rise in the United States and is projected to continue to grow. Speech audiometry, a key component of hearing care, must be customized for this linguistically unique and diverse population. METHOD: The tutorial summarizes recent findings concerning Spanish-English bilinguals' performance on English and Spanish speech audiometric tests in the context of the psychometric properties of the tests and the language and dialect profile of the individual (language status, history, stability, competency, and use). The tutorial also provides arguments for evaluating bilingual clients in Spanish, in English, or in both languages, which may serve as rationales in support of varied bilingual clinical practices. Last, the tutorial provides information regarding Spanish speech audiometry, including available tests, issues that clinicians may encounter when administering them, and dialectal consideration. CONCLUSIONS: It is a challenge as well as an opportunity for clinicians to expand service to the Spanish-English bilingual community. Understanding the characteristics of the individual and the test is essential for ensuring quality services to the bilingual client.

Validating models of clinical word recognition tests for spanish/english bilinguals.

PURPOSE: Shi and Sánchez (2010) developed models to predict the optimal test language for evaluating Spanish/English (S/E) bilinguals' word recognition. The current study intended to validate their conclusions in a separate bilingual listener sample. METHOD: Seventy normal-hearing S/E bilinguals varying in language profile were included. Participants were presented with English monosyllabic and Spanish bisyllabic words in quiet and in speech-spectrum noise (+6 and 0 dB SNR). Relative success on the 2 tests was indicated by the difference in z score for each test. RESULTS: The current group of participants was comparable to participants in Shi and Sánchez (2010) in regard to their language background and test performance. Previously developed models fit current data well. Age of English acquisition (AOAE) yielded more consistent models across test conditions than language dominance (LD). New models incorporating average proficiency rating (across domains) and relative proficiency rating (across languages) yielded best prediction. CONCLUSIONS: Shi and Sánchez's (2010) models incorporating key linguistic variables (AOAE, LD, and average/relative proficiency ratings) can help clinicians predict bilingual clients' relative success in word recognition in Spanish versus English. These models are appropriate for current clinical work with S/E bilinguals in metropolitan areas similar to New York City.

Psychometric function for NU-6 word recognition in noise: effects of first language and dominant language.

OBJECTIVES: The present study attempted to establish psychometric function in individuals whose first language is not English. Psychometric function was obtained for one of the most commonly used clinical tests, the Northwestern University Auditory Test No. 6 (Tillman & Carhart 1966), so that findings could be directly applied to everyday clinical practice. DESIGN: Five groups of 14 normal-hearing, adult listeners differing in their first language and dominant language (English monolinguals, English- and Arabic-dominant Arabic-English bilinguals, and English- and Russian-dominant Russian-English bilinguals) participated. Both forms of the Northwestern University Auditory Test No. 6 test (8 lists of 50 monosyllabic English words) were presented. The lists were randomly assigned to eight signal-to-noise ratios (-3 to 18 dB in 3 dB steps). Listeners responded verbally and in writing. Psychometric functions were derived via logistic regression and described by two parameters: the 50% correct performance level (θ) and the slope (k). RESULTS: Both English-dominant bilingual groups obtained psychometric functions comparable with monolinguals. The θ and k of the functions for these three groups of participants were consistent with the literature. Compared with these three groups, non-English-dominant bilinguals' functions grew significantly more gradually (i.e., a significantly higher θ and a significantly lower k). No differences in either θ or k were found between bilinguals with the same dominant language but different first languages. CONCLUSIONS: Bilinguals reporting themselves to be dominant in English generate monolingual-like psychometric functions. By contrast, a different set of psychometric properties describes the function of bilinguals dominant in their first language. Because first language did not appear to be a significant factor in determining bilinguals' functions, it is concluded that English learning history and English proficiency are more important variables than first language for clinicians to consider when administering English word-recognition tests to their bilingual clients. When working with bilingual clients who are dominant in their first language, clinicians are advised to refer to the normative data reported here specifically for these individuals.

Lexical effects on recognition of the NU-6 words by monolingual and bilingual listeners.

OBJECTIVE: This study investigated how lexical effects account for word recognition in monolinguals versus bilinguals. DESIGN: Listener-specific error rate and familiarity rating of 200 NU-6 words were obtained. Lexical data (normative familiarity, frequency of occurrence, neighborhood density, and frequency of neighborhood competitors) for these words were obtained from the Hoosier mental lexicon. STUDY SAMPLE: Participants included 10 monolinguals and three groups of 10 bilinguals differing mainly in age of acquisition and length of schooling/working in English. RESULTS: Lexical effects were minimal for monolinguals' word recognition. Listener-specific familiarity rating correlated to error rate better than the Hoosier normative rating. Frequency of occurrence was the most significant lexical variable in accounting for bilinguals' measures and its effect was the greatest on bilinguals foreign born and educated. Age of English acquisition tended to affect familiarity rating, whereas length of schooling/working in English tended to affect error rate. CONCLUSIONS: Frequency of word occurrence significantly affects bilinguals' familiarity rating and error rate of the NU-6 words. Listener-specific familiarity rating should be obtained to best predict error rate on the test.

Measuring effectiveness of semantic cues in degraded English sentences in non-native listeners.

OBJECTIVE: This study employed Boothroyd and Nittrouer's k (1988) to directly quantify effectiveness in native versus non-native listeners' use of semantic cues. DESIGN: Listeners were presented speech-perception-in-noise sentences processed at three levels of concurrent multi-talker babble and reverberation. For each condition, 50 sentences with multiple semantic cues and 50 with minimum semantic cues were randomly presented. Listeners verbally reported and wrote down the target words. The metric, k, was derived from percent-correct scores for sentences with and without semantics. STUDY SAMPLE: Ten native and 33 non-native listeners participated. RESULTS: The presence of semantics increased recognition benefit by over 250% for natives, but access to semantics remained limited for non-native listeners (90-135%). The k was comparable across conditions for native listeners, but level-dependent for non-natives. The k for non-natives was significantly different from 1 in all conditions, suggesting semantic cues, though reduced in importance in difficult conditions, were helpful for non-natives. CONCLUSIONS: Non-natives as a group were not as effective in using semantics to facilitate English sentence recognition as natives. Poor listening conditions were particularly adverse to the use of semantics in non-natives, who may rely on clear acoustic-phonetic cues before benefitting from semantic cues when recognizing connected speech.

Performance-intensity functions of Mandarin word recognition tests in noise: test dialect and listener language effects.

PURPOSE: This study established the performance-intensity function for Beijing and Taiwan Mandarin bisyllabic word recognition tests in noise in native speakers of Wu Chinese. Effects of the test dialect and listeners' first language on psychometric variables (i.e., slope and 50%-correct threshold) were analyzed. METHOD: Thirty-two normal-hearing Wu-speaking adults who used Mandarin since early childhood were compared to 16 native Mandarin-speaking adults. Both Beijing and Taiwan bisyllabic word recognition tests were presented at 8 signal-to-noise ratios (SNRs) in 4-dB steps (-12 dB to +16 dB). At each SNR, a half list (25 words) was presented in speech-spectrum noise to listeners' right ear. The order of the test, SNR, and half list was randomized across listeners. Listeners responded orally and in writing. RESULTS: Overall, the Wu-speaking listeners performed comparably to the Mandarin-speaking listeners on both tests. Compared to the Taiwan test, the Beijing test yielded a significantly lower threshold for both the Mandarin- and Wu-speaking listeners, as well as a significantly steeper slope for the Wu-speaking listeners. CONCLUSION: Both Mandarin tests can be used to evaluate Wu-speaking listeners. Of the 2, the Taiwan Mandarin test results in more comparable functions across listener groups. Differences in the performance-intensity function between listener groups and between tests indicate a first language and dialectal effect, respectively.

Dialectal effects on a clinical Spanish word recognition test.

PURPOSE: American Spanish dialects have substantial phonetic and lexical differences. This study investigated how dialectal differences affect Spanish/English bilingual individuals' performance on a clinical Spanish word recognition test. METHOD: Forty Spanish/English bilinguals participated in the study­20 dominant in Spanish and 20 in English.Within each group, 10 listeners spoke the Highland dialect, and 10 spoke the Caribbean/Coastal dialect. Participants were maximally matched between the 2 dialectal groups regarding their demographic and linguistic background. Listeners were randomly presented 4 lists of Auditec Spanish bisyllabic words at 40 dB SL re: pure-tone average. Each list was randomly assigned with a signal-to-noise ratio (SNR) of quiet, +6, +3, and 0 dB, in the presence of speech-spectrum noise. Listeners responded orally and in writing. RESULTS: Dialect and language dominance both significantly affected listener performance on the word recognition test. Higher performance levels were obtained with Highland than Caribbean/Coastal listeners and with Spanish-dominant than English-dominant listeners. The dialectal difference was particularly evident in favorable listening conditions (i.e., quiet and +6 dB SNR) and could not be explained by listeners' familiarity with the test words. CONCLUSION: Dialects significantly affect the clinical assessment of Spanish-speaking clients' word recognition. Clinicians are advised to consider the phonetic features of the dialect when scoring a client's performance.

How "proficient" is proficient? comparison of English and relative proficiency rating as a predictor of bilingual listeners' word recognition.

PURPOSE: The current study attempted to validate that English proficiency self-ratings predict bilinguals' recognition of English words as reported in Shi (2011) and to explore whether relative proficiency ratings (English vs. first language) improve prediction. METHOD: One hundred and twenty-four participants in Shi (2011) and an additional set of 145 participants were included (Groups 1 and 2, respectively) in this study. All listeners rated their proficiency in listening, speaking, and reading (English and first language) on an 11-point scale and listened to a list of words from the Northwestern University Auditory Tests No. 6 (Tillman & Carhart, 1966) at 45 dB HL in quiet. RESULTS: English proficiency ratings by Group 2 yielded sensitivity/specificity values comparable to those of Group 1 (Shi, 2011) in predicting word recognition. A cutoff of 8 or 9 in minimum English proficiency rating across listening, speaking, and reading resulted in the best combination of prediction sensitivity/specificity. When relative proficiency was used, prediction of Group 1 performance significantly improved as compared to English proficiency. Improvement was slight for Group 2, mainly due to low specificity. CONCLUSION: Self-rated English proficiency provides clinically acceptable sensitivity/specificity values as a predictor of bilinguals' English word recognition. Relative proficiency has the potential to further improve predictive power, but the size of improvement depends on the characteristics of the test population.

Understanding native Russian listeners' errors on an English word recognition test: model-based analysis of phoneme confusion.

OBJECTIVE: Word recognition is a basic component in a comprehensive hearing evaluation, but data are lacking for listeners speaking two languages. This study obtained such data for Russian natives in the US and analysed the data using the perceptual assimilation model (PAM) and speech learning model (SLM). DESIGN: Listeners were randomly presented 200 NU-6 words in quiet. Listeners responded verbally and in writing. Performance was scored on words and phonemes (word-initial consonants, vowels, and word-final consonants). STUDY SAMPLE: Seven normal-hearing, adult monolingual English natives (NM), 16 English-dominant (ED), and 15 Russian-dominant (RD) Russian natives participated. ED and RD listeners differed significantly in their language background. RESULTS: Consistent with the SLM, NM outperformed ED listeners and ED outperformed RD listeners, whether responses were scored on words or phonemes. NM and ED listeners shared similar phoneme error patterns, whereas RD listeners' errors had unique patterns that could be largely understood via the PAM. RD listeners had particular difficulty differentiating vowel contrasts /i-I/, /æ-ε/, and /ɑ-Λ/, word-initial consonant contrasts /p-h/ and /b-f/, and word-final contrasts /f-v/. CONCLUSIONS: Both first-language phonology and second-language learning history affect word and phoneme recognition. Current findings may help clinicians differentiate word recognition errors due to language background from hearing pathologies.

Linguistic and attitudinal factors in normal-hearing bilingual listeners' perception of degraded English passages.

PURPOSE: Linguistic variables alone cannot fully account for bilingual listeners' perception of English-running speech. In the present study, the authors investigated how linguistic and attitudinal factors, in combination, affect bilingual processing of temporally degraded English passages in quiet and in noise. METHOD: Thirty-six bilinguals with various linguistic and attitudinal characteristics participated in the study. Bilingual individuals completed questionnaires that assessed their language background, willingness to communicate (WTC), and self-perceived communication competency (SPCC) in English. Participants listened to English passage pairs from the Connected Speech Test, presented at 45 dB HL at 3 rates (unprocessed, expanded, compressed), in quiet and in noise. RESULTS: Language proficiency measures were the most significant linguistic variables, accounting for the largest amount of variance in performance across most conditions. Both WTC and SPCC were associated with performance and contributed to regression models. Subscales assessing listeners' WTC and SPCC in a group were more predictive of performance than communication in an interpersonal or public setting. Performance in noise was more difficult to predict than in quiet. Performance with compression was more difficult to predict than with expansion. CONCLUSION: To fully understand bilingual clients' perception of English speech, hearing professionals should consider their attitudinal characteristics in addition to language background.

Bilingual listeners' perception of temporally manipulated English passages.

PURPOSE: The current study measured, objectively and subjectively, how changes in speech rate affect recognition of English passages in bilingual listeners. METHOD: Ten native monolingual, 20 English-dominant bilingual, and 20 non-English-dominant bilingual listeners repeated target words in English passages at five speech rates (unprocessed, two expanded, and two compressed), in quiet and in noise. For noise conditions, performance was measured at a signal-to-noise ratio that was determined through an adaptive procedure to avoid ceiling and floor effects. Listeners also made subjective judgments of speech rate, speech clarity, and performance confidence. RESULTS: In noise, stepwise improvement was observed as rate slowed down. A similar effect was not found in quiet. This pattern in performance was largely comparable across listener groups but was most robust in English-dominant listeners. Changes in speech rate and presence of noise significantly affected listeners' subjective ratings; however, no intergroup differences were observed for any of the subjective ratings. CONCLUSIONS: Bilingual listeners benefited from slow speech rates, more evidently so in noise than in quiet. Their performance, however, did not reach a monolingual level, even at the most favorable rate. Nonetheless, all listeners reported comparable confidence when processing temporally manipulated English passages.

Contribution of linguistic variables to bilingual listeners' perception of degraded English sentences.

PURPOSE: The present study was designed to investigate what linguistic variables best predict bilingual recognition of acoustically degraded sentences and how to identify bilingual individuals who might have more difficulty than their monolingual counterparts on such tasks. METHOD: Four hundred English speech-perception-in-noise (SPIN) sentences with high and low context were presented in combinations of noise (signal-to-noise ratio: +6 and 0 dB) and reverberation (reverberation time: 1.2 and 3.6 s) to 10 monolingual and 50 bilingual listeners. A detailed linguistic profile was obtained for bilingual listeners using the Language Experience and Proficiency Questionnaire. RESULTS: Variables per reading in English (age of fluency, proficiency, and preference) emerged as strong predictors of performance across noise, reverberation, and context effects. Via discriminant analyses, bilingual listeners who rated their accent to be perceptible and reported shorter length of immersion in an English-spoken country or school tended to score significantly lower on the SPIN test than monolingual listeners. CONCLUSIONS: Bilingual listeners' linguistic background plays a major role in their use of context in degraded English sentences. Rather than conventional variables such as age of acquisition, variables pertaining to reading, proficiency, immersion, and accent severity may be obtained for improved prediction of bilingual performance on the task.