Normal-hearing English-as-a-second-language listeners' recognition of English words in competing signals

Evaluating Hearing Status and Word Recognition Ability in the Hmong Population Using Four Validated Monosyllabic White Hmong Dialect Word Recognition Tests

PURPOSE

The study's aims were (a) to evaluate hearing status and (b) word recognition ability of Hmong speakers using four validated monosyllabic word recognition tests in the White Hmong dialect and (c) to assess the relationship between the participant's language and the average word recognition percent correct scores, adjusting for age, gender, and degree of hearing loss.

METHOD

Participants listened to two randomly assigned validated Hmong word lists (male/female talker) for each ear. Pure-tone air- and bone-conduction thresholds as well as word recognition ability were measured. Descriptive statistics were calculated to analyze the percent correct of word lists and classify hearing status. A nonparametric regression analysis was used to assess the relationship between the participant's language and the average word recognition percent correct scores, adjusting for age, gender, and degree of hearing loss.

RESULTS

Forty-eight Hmong (25 females, 23 males; Mage = 44.4) participated in this study. Thirty-three participants had hearing loss in at least one ear, and 15 had hearing within normal limits bilaterally. Participants with normal, mild, or steeply sloping hearing loss reached an average word recognition score of > 94% on Hmong lists by both male and female talkers. Participants with moderate-to-severe hearing loss scored 68% on average for the male talker Hmong lists and 60% on average for the female talker Hmong lists. Gender was significantly positively associated with average word recognition percent correct on the female word lists (b = -0.224, p = .047) but not statistically significant for the male word lists (b = 7.579, p = .141).

CONCLUSION

Findings provide support for the use of the four Hmong word lists in clinical settings.

Age Impacts Speech-in-Noise Recognition Differently for Nonnative and Native Listeners

PURPOSE

The purpose of this study was to explore potential differences in suprathreshold auditory function among native and nonnative speakers of English as a function of age.

METHOD

Retrospective analyses were performed on three large data sets containing suprathreshold auditory tests completed by 5,572 participants who were self-identified native and nonnative speakers of English between the ages of 18-65 years, including a binaural tone detection test, a digit identification test, and a sentence recognition test.

RESULTS

The analyses show a significant interaction between increasing age and participant group on tests involving speech-based stimuli (digit strings, sentences) but not on the binaural tone detection test. For both speech tests, differences in speech recognition emerged between groups during early adulthood, and increasing age had a more negative impact on word recognition for nonnative compared to native participants. Age-related declines in performance were 2.9 times faster for digit strings and 3.3 times faster for sentences for nonnative participants compared to native participants.

CONCLUSIONS

This set of analyses extends the existing literature by examining interactions between aging and self-identified native English speaker status in several auditory domains in a cohort of adults spanning young adulthood through middle age. The finding that older nonnative English speakers in this age cohort may have greater-than-expected deficits on speech-in-noise perception may have clinical implications on how these individuals should be diagnosed and treated for hearing difficulties.

Mechanisms of long-term repetition priming in recognising speech in noise

Recognition of speech in noise is facilitated when spoken sentences are repeated a few minutes later, but the levels of representation involved in this effect have not been specified. Three experiments tested whether the effect would transfer across modalities and languages. In Experiment 1, participants listened to sets of high- and low-constraint sentences and read other sets in an encoding phase. At test, these sentences and new sentences were presented in noise, and participants attempted to report the final word of each sentence. Recognition was more accurate for repeated than for new sentences in both modalities. Experiment 2 was identical except for the implementation of an articulatory suppression task at encoding to reduce phonological recoding during reading. The cross-modal repetition priming effect persisted but was weaker than when the modality was the same at encoding and test. Experiment 3 showed that the repetition priming effect did not transfer across languages in bilinguals. Taken together, the results indicate that the facilitated recognition of repeated speech is based on a combination of modality-specific processes at the phonological word form level and modality-general processes at the lemma level of lexical representation, but the semantic level of representation is not involved.

Building on the Academic Legacy of Pat Stelmachowicz and other Pioneers in Developmental Psychoacoustics and Pediatric Audiology: The Children's English/Spanish Speech Recognition Test (ChEgSS)

Basic research investigating auditory development often has implications for clinical diagnosis and treatment of hearing loss in children, but it can be challenging to translate those findings into practice. Meeting that challenge was a guiding principle of Pat Stelmachowicz's research and mentorship. Her example inspired many of us to pursue translational research and motivated the recent development of the Children's English/Spanish Speech Recognition Test (ChEgSS). This test evaluates word recognition in noise or two-talker speech, with target and masker speech produced in either English or Spanish. The test uses recorded materials and a forced-choice response, so the tester need not be fluent in the test language. ChEgSS provides a clinical measure of masked speech recognition outcomes for children who speak English, Spanish, or both, including estimates of performance in noise and two-talker speech, with the goal of maximizing speech and hearing outcomes for children with hearing loss. This article highlights several of Pat's many contributions to pediatric hearing research and describes the motivation and development of ChEgSS.

The Involvement of Listening Effort in Explaining Bilingual Listening Under Adverse Listening Conditions

The current review examines listening effort to uncover how it is implicated in bilingual performance under adverse listening conditions. Various measures of listening effort, including physiological, behavioral, and subjective measures, have been employed to examine listening effort in bilingual children and adults. Adverse listening conditions, stemming from environmental factors, as well as factors related to the speaker or listener, have been examined. The existing literature, although relatively limited to date, points to increased listening effort among bilinguals in their nondominant second language (L2) compared to their dominant first language (L1) and relative to monolinguals. Interestingly, increased effort is often observed even when speech intelligibility remains unaffected. These findings emphasize the importance of considering listening effort alongside speech intelligibility. Building upon the insights gained from the current review, we propose that various factors may modulate the observed effects. These include the particular measure selected to examine listening effort, the characteristics of the adverse condition, as well as factors related to the particular linguistic background of the bilingual speaker. Critically, further research is needed to better understand the impact of these factors on listening effort. The review outlines avenues for future research that would promote a comprehensive understanding of listening effort in bilingual individuals.

Validating Four Hmong Word Recognition Tests With Normal-Hearing Bilingual Hmong Individuals

Purpose:

The purpose of this study was to validate four digitally recorded and phonetically balanced 50-word recognition lists in the White Hmong dialect with normal-hearing bilingual Hmong adults.

Method:

Using a randomized, incomplete-block design, each participant listened to and repeated four unique Hmong lists delivered by a female and a male talker. Participants were also tested with an English word list—List 1A of the Northwestern University Auditory Test No. 6. Participants' correct pronunciation of each word was scored. A nonparametric Mann–Whitney U Location Difference Test for Equivalence using two one-sided tests equivalence hypothesis: −0.02 < [(List_1) – (List_2)] < 0.02 was conducted to assess equivalence among all four Hmong and the English lists.

Results:

Seventy Hmong speakers participated in this study (35 women, 35 men; M age = 29.5 years, SD = 7.1). In all four Hmong lists, 93.5% (187/200) words met the validation criteria for ≥ 92% correct pronunciation. The 13 difficult words were deemed adequate by a Hmong panel and, therefore, were included to maintain four unique, balanced word lists. The test revealed that the Hmong and English word lists were considered equivalent at the 2% bound.

Conclusion:

The four Hmong word lists were validated to ensure an equal range of word difficulty across the lists.

Masked-Speech Recognition for Linguistically Diverse Populations: A Focused Review and Suggestions for the Future

PURPOSE

Twenty years ago, von Hapsburg and Peña (2002) wrote a tutorial that reviewed the literature on speech audiometry and bilingualism and outlined valuable recommendations to increase the rigor of the evidence base. This review article returns to that seminal tutorial to reflect on how that advice was applied over the last 20 years and to provide updated recommendations for future inquiry.

METHOD

We conducted a focused review of the literature on masked-speech recognition for bilingual children and adults. First, we evaluated how studies published since 2002 described bilingual participants. Second, we reviewed the literature on native language masked-speech recognition. Third, we discussed theoretically motivated experimental work. Fourth, we outlined how recent research in bilingual speech recognition can be used to improve clinical practice.

RESULTS

Research conducted since 2002 commonly describes bilingual samples in terms of their language status, competency, and history. Bilingualism was not consistently associated with poor masked-speech recognition. For example, bilinguals who were exposed to English prior to age 7 years and who were dominant in English performed comparably to monolinguals for masked-sentence recognition tasks. To the best of our knowledge, there are no data to document the masked-speech recognition ability of these bilinguals in their other language compared to a second monolingual group, which is an important next step. Nonetheless, individual factors that commonly vary within bilingual populations were associated with masked-speech recognition and included language dominance, competency, and age of acquisition. We identified methodological issues in sampling strategies that could, in part, be responsible for inconsistent findings between studies. For instance, disparities in socioeconomic status (SES) between recruited bilingual and monolingual groups could cause confounding bias within the research design.

CONCLUSIONS

Dimensions of the bilingual linguistic profile should be considered in clinical practice to inform counseling and (re)habilitation strategies since susceptibility to masking is elevated in at least one language for most bilinguals. Future research should continue to report language status, competency, and history but should also report language stability and demand for use data. In addition, potential confounds (e.g., SES, educational attainment) when making group comparisons between monolinguals and bilinguals must be considered.

Masked English Speech Recognition Performance in Younger and Older Spanish-English Bilingual and English Monolingual Children

Purpose The purpose of this study was to compare masked English speech recognition thresholds between Spanish-English bilingual and English monolingual children and to evaluate effects of age, maternal education, and English receptive language abilities on individual differences in masked speech recognition. Method Forty-three Spanish-English bilingual children and 42 English monolingual children completed an English sentence recognition task in 2 masker conditions: (a) speech-shaped noise and (b) 2-talker English speech. Two age groups of children, younger (5-6 years) and older (9-10 years), were tested. The predictors of masked speech recognition performance were evaluated using 2 mixed-effects regression models. In the 1st model, fixed effects were age group (younger children vs. older children), language group (bilingual vs. monolingual), and masker type (speech-shaped noise vs. 2-talker speech). In the 2nd model, the fixed effects of receptive English vocabulary scores and maternal education level were also included. Results Younger children performed more poorly than older children, but no significant difference in masked speech recognition was observed between bilingual and monolingual children for either age group when English proficiency and maternal education were also included in the model. English language abilities fell within age-appropriate norms for both groups, but individual children with larger receptive vocabularies in English tended to show better recognition; this effect was stronger for younger children than for older children. Speech reception thresholds for all children were lower in the speech-shaped noise masker than in the 2-talker speech masker. Conclusions Regardless of age, similar masked speech recognition was observed for Spanish-English bilingual and English monolingual children tested in this study when receptive English language abilities were accounted for. Receptive English vocabulary scores were associated with better masked speech recognition performance for both bilinguals and monolinguals, with a stronger relationship observed for younger children than older children. Further investigation involving a Spanish-dominant bilingual sample is warranted given the high English language proficiency of children included in this study.

Effects of Language History on Sentence Recognition in Noise or Two-Talker Speech: Monolingual, Early Bilingual, and Late Bilingual Speakers of English

Purpose Language history is an important factor in masked speech recognition. Listeners who acquire the target language later in life perform more poorly than native speakers. However, there are inconsistencies in the literature regarding performance of bilingual speakers who begin learning the target language early in life. The purpose of this experiment was to evaluate speech-in-noise and speech-in-speech recognition for highly proficient early bilingual listeners compared to monolingual and late bilingual listeners. Method Three groups of young adults participated: native monolingual English speakers, bilingual Mandarin-English speakers who learned English from birth (early bilinguals), and native Mandarin speakers who learned English later in life (late bilinguals). All participants had normal hearing and were full-time college students. Recognition was assessed for English sentences in speech-shaped noise and two-talker English speech. Participants provided linguistic and demographic information, and late bilinguals completed the Versant test of spoken English abilities. Results All listeners performed better in speech-shaped noise than two-talker speech. Performance was similar for monolingual and early bilinguals. Late bilinguals performed more poorly overall. There was evidence for a stronger association between masked speech recognition and English dominance for late bilinguals compared to early bilinguals. Conclusion These results support the conclusion that bilingualism itself does not necessarily result in a disadvantage when recognizing masked speech in noise and speech in speech. For populations similar to those studied here (highly proficient early bilinguals), it would be appropriate to evaluate masked speech recognition using the same simple stimuli and normative data used for monolingual speakers of English.

Perception of Native English Reduced Forms in Adverse Environments by Chinese Undergraduate Students

Previous research has shown that learners of English-as-a-second-language (ESL) have difficulties in understanding connected speech spoken by native English speakers. Extending from past research limited to quiet listening condition, this study examined the perception of English connected speech presented under five adverse conditions, namely multi-talker babble noise, speech-shaped noise, factory noise, whispering and sad emotional tones. We tested a total of 64 Chinese ESL undergraduate students, using a battery of listening tasks. Results confirmed that the recognition of English native speech was more challenging for Chinese ESL learners under unfavorable listening conditions, in comparison to a noise-free listening condition. These findings carry significant implications for the importance of training and assessments on connected speech perception across various listening environments.

The Bilingual Disadvantage in Speech Understanding in Noise Is Likely a Frequency Effect Related to Reduced Language Exposure

The present study sought to explain why bilingual speakers are disadvantaged relative to monolingual speakers when it comes to speech understanding in noise. Exemplar models of the mental lexicon hold that each encounter with a word leaves a memory trace in long-term memory. Words that we encounter frequently will be associated with richer phonetic representations in memory and therefore recognized faster and more accurately than less frequently encountered words. Because bilinguals are exposed to each of their languages less often than monolinguals by virtue of speaking two languages, they encounter all words less frequently and may therefore have poorer phonetic representations of all words compared to monolinguals. In the present study, vocabulary size was taken as an estimate for language exposure and the prediction was made that both vocabulary size and word frequency would be associated with recognition accuracy for words presented in noise. Forty-eight early Spanish–English bilingual and 53 monolingual English young adults were tested on speech understanding in noise (SUN) ability, English oral verbal ability, verbal working memory (WM), and auditory attention. Results showed that, as a group, monolinguals recognized significantly more words than bilinguals. However, this effect was attenuated by language proficiency; higher proficiency was associated with higher accuracy on the SUN test in both groups. This suggests that greater language exposure is associated with better SUN. Word frequency modulated recognition accuracy and the difference between groups was largest for low frequency words, suggesting that the bilinguals’ insufficient exposure to these words hampered recognition. The effect of WM was not significant, likely because of its large shared variance with language proficiency. The effect of auditory attention was small but significant. These results are discussed within the Ease of Language Understanding model (Rönnberg et al., 2013), which provides a framework for explaining individual differences in SUN.

Influence of language experience on digit recognition by English and Chinese listeners

Digit recognition was measured in quiet and in two noise conditions by English-native (EN) and Chinese-native (CN) listeners. EN listeners were tested using English digits and CN listeners were tested using both English and Chinese digits. In quiet, forward digit span recall worsened for both groups as the number of digits was increased. Significant effects of language experience were observed with five or more digits. Language experience had a significant effect on digit recognition in babble but not in steady noise. These results suggest that understanding of a nonnative language can be influenced by both cognitive load and listening environment.

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.

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.

Development and preliminary evaluation of a pediatric Spanish-English speech perception task

PURPOSE

The purpose of this study was to develop a task to evaluate children's English and Spanish speech perception abilities in either noise or competing speech maskers.

METHOD

Eight bilingual Spanish-English and 8 age-matched monolingual English children (ages 4.9-16.4 years) were tested. A forced-choice, picture-pointing paradigm was selected for adaptively estimating masked speech reception thresholds. Speech stimuli were spoken by simultaneous bilingual Spanish-English talkers. The target stimuli were 30 disyllabic English and Spanish words, familiar to 5-year-olds and easily illustrated. Competing stimuli included either 2-talker English or 2-talker Spanish speech (corresponding to target language) and spectrally matched noise.

RESULTS

For both groups of children, regardless of test language, performance was significantly worse for the 2-talker than for the noise masker condition. No difference in performance was found between bilingual and monolingual children. Bilingual children performed significantly better in English than in Spanish in competing speech. For all listening conditions, performance improved with increasing age.

CONCLUSIONS

Results indicated that the stimuli and task were appropriate for speech recognition testing in both languages, providing a more conventional measure of speech-in-noise perception as well as a measure of complex listening. Further research is needed to determine performance for Spanish-dominant listeners and to evaluate the feasibility of implementation into routine clinical use.

Effects of linguistic experience on the ability to benefit from temporal and spectral masker modulation

Masked speech perception can often be improved by modulating the masker temporally and/or spectrally. These effects tend to be larger in normal-hearing listeners than hearing-impaired listeners, and effects of temporal modulation are larger in adults than young children [Hall et al. (2012). Ear Hear. 33, 340-348]. Initial reports indicate non-native adult speakers of the target language also have a reduced ability to benefit from temporal masker modulation [Stuart et al. (2010). J. Am. Acad. Aud. 21, 239-248]. The present study further investigated the effect of masker modulation on English speech recognition in normal-hearing adults who are non-native speakers of English. Sentence recognition was assessed in a steady-state baseline masker condition and in three modulated masker conditions, characterized by spectral, temporal, or spectro-temporal modulation. Thresholds for non-natives were poorer than those of native English speakers in all conditions, particularly in the presence of a modulated masker. The group differences were consistent across maskers when assessed in percent correct, suggesting that a single factor may limit the performance of non-native listeners similarly in all conditions.

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.

Comparison of auditory temporal resolution between monolingual Persian and bilingual Turkish-Persian individuals

OBJECTIVE

The aims of this study were to prepare a Persian version of the temporal resolution test using the method of Phillips et al (1994) and Stuart and Phillips (1996), and to compare the word-recognition performance in the presence of continuous and interrupted noise as well as the temporal resolution abilities between monolingual (ML) Persian and bilingual (BL) Turkish-Persian young adults.

DESIGN

Word-recognition scores (WRSs) were obtained in quiet and in the presence of background competing continuous and interrupted noise at signal-to-noise ratios (SNRs) of -20, -10, 0, and 10 dB.

STUDY SAMPLE

Two groups of 33 ML Persian and 36 BL Turkish-Persian volunteers participated.

RESULTS

WRSs significantly differed between ML and BL subjects at four sensation levels in the presence of continuous and interrupted noise. However, the difference in the release from masking between ML and BL subjects was not significant at the studied SNRs.

CONCLUSIONS

BL Turkish-Persian listeners seem to show poorer performance when responding to Persian words in continuous and interrupted noise. However, bilingualism may not affect auditory temporal resolution ability.

The impacts of language background and language-related disorders in auditory processing assessment

PURPOSE

To examine the impact of language background and language-related disorders (LRDs--dyslexia and/or language impairment) on performance in English speech and nonspeech tests of auditory processing (AP) commonly used in the clinic.

METHOD

A clinical database concerning 133 multilingual children (mostly with English as an additional language) and 71 monolingual children (7- to 12-year-old native English speakers) with listening concerns was analyzed retrospectively.

RESULTS

Language background had no significant effect on the 3 nonspeech AP tests, but the multilingual group performed worse in most of the speech tests. Children with LRDs generally performed more poorly than those without, except for the masking level difference.

CONCLUSIONS

Although language background affects performance in AP tasks that use speech, the effect of LRDs appears to be more wide-ranging insofar as the majority of the AP tests--speech and nonspeech--were significantly affected by their presence. The effects of language background are probably mediated directly through the effects of language expertise, whereas those associated with LRDs appear to arise from associated deficits in memory and attention. The vast majority of so-called AP tests tap abilities far beyond those typically thought of as specifically auditory; thus, they are poor measures of an AP disorder.

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.

How “Proficient” Is Proficient? Subjective Proficiency as a Predictor of Bilingual Listeners’ Recognition of English Words

Purpose

English proficiency must be considered when a bilingual individual is to be evaluated clinically with English speech material. This study describes the minimum level of self-reported English proficiency that identifies bilingual individuals who may perform on par with monolingual listeners on an English word recognition test.

Method

A total of 125 normal hearing bilingual listeners rated their English proficiency in listening, speaking, and reading on an 11-point scale. Other related linguistic variables were also obtained. A randomly selected Northwestern University Auditory Test No. 6 (NU-6) list (50 English monosyllabic words) was presented to all participants at 45 dB HL in quiet.

Results

Over 90% of the listeners self-rated to have at least “good” proficiency in English listening, speaking, or reading. Of these participants, more than 30% did not achieve a monolingual normative level in English as delimited by binomial distribution. Composite proficiency ratings across language domains better predicted word recognition performance than self-ratings for listening proficiency only. Combining language dominance and age of English acquisition with proficiency ratings further improved prediction specificity.

Conclusions

Self-rated English proficiency can predict bilingual listeners’ performance on the NU-6 test. For desirable sensitivity and specificity in predicting monolingual-like performance, a minimum rating of 8 out of 10 across all language domains is recommended.

Spanish/English bilingual listeners on clinical word recognition tests: what to expect and how to predict

PURPOSE

The current study was an attempt to provide initial evidence on how to predict the optimal language in which to conduct speech perception testing for Spanish/English (S/E) bilingual listeners.

METHOD

Thirty normal-hearing S/E listeners differing in age of language acquisition, length of immersion, daily language use, self-rated listening proficiency, and language dominance were evaluated on the English and Spanish word recognition tests in quiet and in speech-spectrum noise.

RESULTS

Performance on the English and Spanish tests was not correlated for any conditions. English word recognition was most significantly correlated with age of English acquisition. Logistic regression analyses further demonstrated age of English acquisition to be a good predictor of listeners' relative success on the 2 tests in quiet and at +6 dB signal-to-noise ratio (SNR). At 0 dB SNR, language dominance had the highest predictive specificity, whereas the combination of age of English acquisition and Spanish listening proficiency had the highest sensitivity.

CONCLUSIONS

A Spanish word recognition test would likely yield more favorable results for S/E bilingual listeners who were Spanish-dominant or who acquired English at 10 years of age or older. It may be necessary for listeners who acquired English at 7-10 years of age to be evaluated in both English and Spanish.

Perception of acoustically degraded sentences in bilingual listeners who differ in age of english acquisition

PURPOSE

The effects of acoustic degradation and context use on sentence perception were evaluated in listeners differing in age of English acquisition.

METHOD

Five groups of 8 listeners, native monolingual (NM), native bilingual (NB), and early, late, and very late non-native bilingual (NN-E, NN-L, and NN-VL, respectively), identified target words in 400 Speech-Perception-in-Noise (SPIN) sentences presented in 8 combinations of noise (+6 vs. 0 dB signal-to-noise ratio), reverberation (1.2 vs. 3.6 s reverberation time), and context (high vs. low predictability).

RESULTS

Separate effects of noise, reverberation, and context were largely level dependent and more significant than their interaction with listeners' age of English acquisition. However, the effect of noise, as well as the combined effect of reverberation and context, was mediated by age of acquisition. NN-VL listeners' performance was significantly compromised in all test conditions. NB, NN-E, and NN-L listeners' use of context, by contrast, deviated substantially from the monolingual normative in difficult listening conditions.

CONCLUSIONS

Findings suggest that linguistic background needs to be considered in the understanding of bilingual listeners' context use in acoustically degraded conditions. Direct comparison of early bilingual listeners' performance with monolingual norms may be inappropriate when speech is highly degraded.

Masking effects of speech and music: does the masker's hierarchical structure matter?

Speech and music are time-varying signals organized by parallel hierarchical rules. Through a series of four experiments, this study compared the masking effects of single-talker speech and instrumental music on speech perception while manipulating the complexity of hierarchical and temporal structures of the maskers. Listeners' word recognition was found to be similar between hierarchically intact and disrupted speech or classical music maskers (Experiment 1). When sentences served as the signal, significantly greater masking effects were observed with disrupted than intact speech or classical music maskers (Experiment 2), although not with jazz or serial music maskers, which differed from the classical music masker in their hierarchical structures (Experiment 3). Removing the classical music masker's temporal dynamics or partially restoring it affected listeners' sentence recognition; yet, differences in performance between intact and disrupted maskers remained robust (Experiment 4). Hence, the effect of structural expectancy was largely present across maskers when comparing them before and after their hierarchical structure was purposefully disrupted. This effect seemed to lend support to the auditory stream segregation theory.