Monolingual English Listeners Research Articles

Perceptual representation of speaker gender in Spanish-English bilingual listeners

The perceptual representation of speaker gender in monolingual English listeners has been found to be gradient and 2-dimensional. However, both gender expression and listener attribution of a speaker’s gender are known to vary by cultural and linguistic norms. Thus, listeners’ attribution of a speaker’s gender is expected to vary based on the cultural and linguistic practices of their community. This study examined the perceptual representation of speaker gender in Spanish-English bilingual listeners at the U.S./Mexico border of El Paso, TX. Twenty-four Spanish-English bilingual speakers of diverse gender identities (e.g., cisgender men, cisgender women, and transgender women) were audio recorded reading sentences from the English and Spanish versions of the Hearing in Noise Test. Nineteen cisgender Spanish-English bilingual listeners completed an auditory free classification paradigm, in which they classified speakers by perceived general similarity and gender identity in both Spanish and English conditions. Multidimensional scaling of listeners’ classifications in each language revealed that listeners organized speakers in a more expansive perceptual space in English (3 dimensions) as compared to Spanish (2 dimensions). Dimension weightings indicated that, in Spanish, listeners placed more emphasis on Dimension 1 as compared to Dimension 2 when classifying speakers, while, in English, listeners equally weighted the 3 dimensions.

Target-masker onset asynchrony modulates linguistic release from masking

Speech-in-speech recognition is a challenge that listeners often encounter. Performance in such situations is improved if the competing speech is in a language different from the target—a phenomenon called Linguistic Release from Masking (LRM). LRM occurs due to a combination of energetic masking that arises from the physical overlap between the target signal and the masker and informational masking that arises from cognitive, attentional, and other factors. The contributions of informational masking to LRM is poorly understood. In the current study, we manipulated informational masking by varying the target-masker onset asynchrony while holding energetic masking constant. Typical, monolingual English listeners transcribed BKB sentences with either English or Mandarin two-talker babble in the background. The target sentences started either simultaneously with the masker, 500 ms after the masker, or 1000 ms after the masker. Listening accuracy was higher for the Mandarin than for the English masker, replicating typical LRM. However, the size of LRM was moderated by onset asynchrony with larger effects for longer lag times. This finding suggests that the detrimental effect of English masker accrues with lag. Implications of this finding for the role of informational masking in speech-in-speech listening will be discussed.

Listening effort for L2 accents: Adults’ adaptation to Mandarin accented english

Using task-evoked pupillary response (TEPR) and dual-task procedures, prior research has shown that adults recruit additional cognitive resources when processing fully intelligible L2-accented speech compared to speech in their own L1 accent (McLaughlin and Van Engen, 2020; Brown et al., 2020). In this study, we investigated the relationship between three prosodic measures (relative word duration variance, pitch stability, and pitch range) and changes in listening effort for L1 and L2 speakers over the course of an experiment. Using growth curve analysis, we found significant interactions between each of the three measures and trial number, indicating that prosodic factors influence speech adaptation. However, these interactions were in opposite directions for the L1 and L2 speakers. Thus, adult monolingual English listeners rely on prosodic information to adapt to a particular speaker’s voice, but use that information differently based on speaker identity.

Categorization and discrimination of Mandarin lexical tones by naïve English listeners

Unlike tone languages such as Mandarin, English lacks tones at the sub-lexical level. Accordingly, English listeners have difficulty perceptually assimilating tones as categorized or uncategorized native segments (Perceptual Assimilation Model, PAM: Best, 1995). While English listeners can categorize the four lexical tones of Mandarin, i.e., level contour, rising, dipping, and falling, when given question, statement, exclamation, and uncertainty intonations as category choices (So & Best, 2011, 2014), this does not address tone assimilation at the segmental level. We reasoned that they might assimilate tones as non-assimilable nonspeech patterns if given visual icons as tone category choices (flat, rising, dipping, and falling lines, respectively), with no reference being made to English intonation categories. Accordingly, 76 monolingual English listeners (M age = 24.85 years, 50 females) were set two tasks: to use visual icons to categorize Mandarin tones in naturally produced tone-words (/ga, ti, tu, pu/ × 4 tones) and to discriminate all six pairwise tone contrasts. All tone pairs showed ceiling-level discrimination, and listeners split their categorizations of falling and level stimuli between the falling and flat icons, suggesting that when given visual icons, tone-naïve English listeners perceive Mandarin tones as nonspeech acoustic patterns, which is consistent with PAM’s non-assimilation predictions.

Orthographic influence in the distributional learning of non-native speech sounds

This study investigated the role of orthographic information in the acquisition of non-native speech sounds by monolingual English listeners. Two potentially important orthographic variables were explored: Orthographic compatibility (whether the orthographic information supports or contradicts the distributional information) and orthographic familiarity (whether the native and target languages share the same orthography). Ten groups of learners were trained on either a unimodal or bimodal distribution of two length continua. Out of the 10 groups, eight groups were also exposed to orthographic cues that varied in their compatibility with the distributional information (compatible vs. incompatible) and familiarity with the orthography of learners’ native language (Roman vs. Arabic). Following training, all participants performed an AX discrimination task to test their discrimination of the length contrast. The results revealed that, in general, the availability of either familiar or unfamiliar orthographic input which signaled the existence of a single length category significantly lowered learners’ discrimination of the length contrast regardless of the auditory distribution. Further, the exposure to orthographic input that supported a two-category length distinction enhanced the discrimination of the length contrast irrespective of the distribution. However, the most significant improvement occurred when both distributional information and familiar orthographic input were compatible. Overall, these findings indicate that orthographic input, regardless of its level of compatibility or familiarity, may influence the acquisition of non-native speech sounds.

The cognitive demands of adverse listening conditions for monolingual and bilingual listeners: A pupillometry study

Bilinguals typically underperform relative to monolinguals in speech-perception-in-noise tasks. However, there is little data comparing bilinguals and monolinguals in other types of difficult listening conditions. Furthermore, such differences are typically investigated using off-line intelligibility accuracy scores, which do not necessarily reflect differences in on-line speech processing. In the current study, pupillometry was used during sentence recognition tasks to index cognitive processing load. Monolingual English listeners and English-dominant simultaneous bilingual listeners heard English sentences in four conditions: American-Accented in Quiet, Turkish-Accented in Quiet, American-Accented in Noise, and Face Mask-Attenuated American-Accented in Quiet. Differences in pupil dilation between groups are expected in the latter three conditions. Data collection is on-going, but preliminary results (N = 40) show bilinguals exert more cognitive effort than monolinguals across all conditions.

Accent rating of noise- and tone-vocoded foreign-accented speech

There are abundant acoustic-phonetic cues in speech signals for listeners to encode talker identity. However, speech signals in the real world are always less optimal due to various adverse listening sources. Vocoded speech is one type of simplified signal that has less spectral and/or temporal information in comparison to normal speech. The purpose of this study is to examine whether and how listeners’ judgment of talker accent is affected by noise and tone vocoding. Twelve Mandarin-accented English speakers with varying degree of accentedness and two native English speakers were recorded reading “The Rainbow Passage.” The recorded speech samples from each talker were segmented into small sections that were randomly selected for noise- or tone-excited vocoder processing into 1, 2, 4, 8, and 16 channels. The vocoded and unprocessed speech samples were randomly presented to a group of normal-hearing, monolingual English listeners for accent rating. The listeners judged the degree of talker accent on a 9-point Likert scale with “1” representing no accent and “9” representing extremely strong accent. The data are still in the process of being collected and analyzed. Results and implications of the present study will be discussed.

The Effects of Clear Speech on American English Listener Perception of Spanish-Accented and Native English Speech

Purpose The purpose of this study was to explore (a) the effect of clear speech on intelligibility, ease of understanding, and accentedness in Spanish-accented and native English speakers of American English and (b) the extent to which accentedness predicts intelligibility and ease of understanding. Method Ten adult talkers, five native English speakers and five native Spanish speakers, read aloud 28 short sentences in habitual speech and clear speech. One hundred monolingual English listeners transcribed what they heard and rated ease of understanding using a 10-cm visual analog scale while hearing the sentences in six-talker babble. Then, accentedness (using a visual analog scale) was judged in quiet. Intelligibility was calculated as the number of words transcribed correctly for each sentence. Ten listeners with significant exposure to Spanish-accented speech rated each talker. Each listener heard only one talker, rating half the sentences in clear speech and half in habitual speech, so that no listener heard a sentence more than once for the intelligibility and ease of understanding assessments. Results Clear speech improved intelligibility and ease of understanding for both language groups, with greater improvement in nonnative talkers. Clear speech did not alter accentedness in nonnative talkers but did increase accentedness in native talkers. Accentedness did not strongly predict intelligibility but did predict ease of understanding, although the relationship was nonlinear. Conclusions Listeners who are experienced in hearing Spanish-accented speech derive significant benefits from clear speech. The difference in the predictability of accentedness for intelligibility and ease of understanding contributes further evidence to the difference in underlying cognitive processes for these two variables.

EFFECTS OF MULTITALKER INPUT AND INSTRUCTIONAL METHOD ON THE DIMENSION-BASED STATISTICAL LEARNING OF SYLLABLE-TONE COMBINATIONS

AbstractTo test the effects of talker variability and explicit instruction on the statistical learning of lexical tone, 80 monolingual English listeners were taught an artificial language that mimicked Mandarin’s asymmetric distribution of syllable-tone co-occurrences. Training stimuli consisted of either speech from one talker or speech from four talkers. Participants were either never instructed or explicitly taught associations between phonemes (CVs), tones, and nonce symbols across four consecutive days. Learning was assessed by the accuracy of mouse clicks and eye movements to visual nonce symbols. Critical trials induced competition between the target symbol, which matched the acoustic input, and a competitor symbol that had a statistically more probable tone (but mismatched the acoustic input). Eye fixations indicated that participants were sensitive to syllable-tone co-occurrence probabilities even without explicit instruction of tone. The degree to which statistical knowledge was used to recognize words appeared to increase when participants processed more variable speech.

Language Specificity in Phonetic Cue Weighting: Monolingual and Bilingual Perception of the Stop Voicing Contrast in English and Spanish

Background/Aims: This work examines the perception of the stop voicing contrast in Spanish and English along four acoustic dimensions, comparing monolingual and bilingual listeners. Our primary goals are to test the extent to which cue-weighting strategies are language-specific in monolinguals, and whether this language specificity extends to bilingual listeners. Methods: Participants categorized sounds varying in voice onset time (VOT, the primary cue to the contrast) and three secondary cues: fundamental frequency at vowel onset, first formant (F1) onset frequency, and stop closure duration. Listeners heard acoustically identical target stimuli, within language-specific carrier phrases, in English and Spanish modes. Results: While all listener groups used all cues, monolingual English listeners relied more on F1, and less on closure duration, than monolingual Spanish listeners, indicating language specificity in cue use. Early bilingual listeners used the three secondary cues similarly in English and Spanish, despite showing language-specific VOT boundaries. Conclusion: While our findings reinforce previous work demonstrating language-specific phonetic representations in bilinguals in terms of VOT boundary, they suggest that this specificity may not extend straightforwardly to cue-weighting strategies.

The Massive Auditory Lexical Decision (MALD) database.

The Massive Auditory Lexical Decision (MALD) database is an end-to-end, freely available auditory and production data set for speech and psycholinguistic research, providing time-aligned stimulus recordings for 26,793 words and 9592 pseudowords, and response data for 227,179 auditory lexical decisions from 231 unique monolingual English listeners. In addition to the experimental data, we provide many precompiled listener- and item-level descriptor variables. This data set makes it easy to explore responses, build and test theories, and compare a wide range of models. We present summary statistics and analyses.

The effect of clear speech on listener perception of nonnative speech

Listener perception of nonnative speech may be measured as intelligibility, ease of understanding, or accentedness. The relationship among these variables is complex, as is the influence of clear speech on these measures. The purpose of this study was to explore the effect on listener perception of clear speech produced by Spanish-accented talkers of American English. Specifically, four questions guided this study: Does clear speech enhance intelligibility and ease of understanding? What is the effect of clear speech on accentedness? How does speaking style (conversational versus clear) influence the relationship among these perceptual variables? Does the presence or absence of supporting contextual information modify the relationship among intelligibility, ease of understanding, and accentedness? Twenty-eight female talkers of American English (half native English-speaking and half Spanish-accented) read aloud 56 short sentences using conversational and clear speech. The 56 sentences were comprised of 28 pairs, each containing a high- or low-probability final word. Young, normal-hearing, monolingual English listeners transcribed and rated ease of understanding for sentences presented in 12-talker babble, and then rated accentedness for sentences presented in quiet. Listeners assigned ratings using visual analog scales. Results and their implications for models of listener perception and clinical management of accentedness will be discussed.

Experience with a second language affects the use of fundamental frequency in speech segmentation.

This study investigates whether listeners’ experience with a second language learned later in life affects their use of fundamental frequency (F0) as a cue to word boundaries in the segmentation of an artificial language (AL), particularly when the cues to word boundaries conflict between the first language (L1) and second language (L2). F0 signals phrase-final (and thus word-final) boundaries in French but word-initial boundaries in English. Participants were functionally monolingual French listeners, functionally monolingual English listeners, bilingual L1-English L2-French listeners, and bilingual L1-French L2-English listeners. They completed the AL-segmentation task with F0 signaling word-final boundaries or without prosodic cues to word boundaries (monolingual groups only). After listening to the AL, participants completed a forced-choice word-identification task in which the foils were either non-words or part-words. The results show that the monolingual French listeners, but not the monolingual English listeners, performed better in the presence of F0 cues than in the absence of such cues. Moreover, bilingual status modulated listeners’ use of F0 cues to word-final boundaries, with bilingual French listeners performing less accurately than monolingual French listeners on both word types but with bilingual English listeners performing more accurately than monolingual English listeners on non-words. These findings not only confirm that speech segmentation is modulated by the L1, but also newly demonstrate that listeners’ experience with the L2 (French or English) affects their use of F0 cues in speech segmentation. This suggests that listeners’ use of prosodic cues to word boundaries is adaptive and non-selective, and can change as a function of language experience.

Effects of intelligibility on within- and cross-modal sentence recognition memory

Listener-oriented speaking style adaptations improve sentence recognition memory in quiet and in noise (Van Engen et al. 2012, Gilbert et al. 2014). It is not clear if this advantage arises from the available cognitive resources, or enhanced memory traces. The present study investigated what may underlie the improved recognition memory for clear speech. In the within-modal condition, monolingual English listeners heard a total of 40 unique meaningful sentences in conversational and clear speaking styles, followed by a test phase in which they identified 80 audio sentences as old or new. In the cross-modal condition, the acoustic input in the test phase was replaced by written text. Results showed that while accuracy was high in both conditions, conversational-to-clear speech modifications significantly improved sentence recognition memory only in the within-modal condition. In the cross-modal condition, speaking style had no effect on sentence recognition memory. The results suggest that the benefit of clear speech over conversational speech on recognition memory lies in exaggerated acoustic-phonetic cues whose presence is necessary to activate memory traces. Speaking style adaptations may promote the encoding and storing of lower-level acoustic information rather than higher-level semantic information.

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

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. This preliminary study investigated how heritage speakers of Spanish perform on an English word recognition test and analyzed their phoneme errors. A prospective, cross-sectional, observational design was employed. 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. 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. 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/. 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.

English listeners’ judgments of Japanese-accented English vowel productions: Relation to acoustic and kinematic characteristics

The present study investigates how monolingual English listeners categorize foreign (Japanese) productions of English tense and lax vowels with the aim of relating vowel identification to the acoustic and kinematic vowel space. American English front vowels (/i/, /ɪ/, /e/, /ɛ/, and /ae/) were elicited in /hVd/ context from ten Japanese adults who learned English as a second language (ESL). Listeners categorized these vowel productions in a six-alternative, forced-choice paradigm (including the choice /ʌ/). Vowels produced by two native English speakers were included in the perceptual task for comparison. Preliminary results showed higher perceptual accuracy for tense vowels than for lax vowels. As expected, vowels from English talkers were more accurately identified than those from Japanese ESL speakers. To determine whether listeners’ perceptual categorization corresponded with acoustic and kinematic patterns, perceptual data for contrasting vowel categories were compared with measured differences in form...

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

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. 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. 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. 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.

Differences in the Association between Segment and Language: Early Bilinguals Pattern with Monolinguals and Are Less Accurate than Late Bilinguals.

Early bilinguals often show as much sensitivity to L2-specific contrasts as monolingual speakers of the L2, but most work on cross-language speech perception has focused on isolated segments, and typically only on neighboring vowels or stop contrasts. In tasks that include sounds in context, listeners’ success is more variable, so segment discrimination in isolation may not adequately represent the phonetic detail in stored representations. The current study explores the relationship between language experience and sensitivity to segmental cues in context by comparing the categorization patterns of monolingual English listeners and early and late Spanish–English bilinguals. Participants categorized nonce words containing different classes of English- and Spanish-specific sounds as being more English-like or more Spanish-like; target segments included phonemic cues, cues for which there is no analogous sound in the other language, or phonetic cues, cues for which English and Spanish share the category but for which each language varies in its phonetic implementation. Listeners’ language categorization accuracy and reaction times were analyzed. Our results reveal a largely uniform categorization pattern across listener groups: Spanish cues were categorized more accurately than English cues, and phonemic cues were easier for listeners to categorize than phonetic cues. There were no differences in the sensitivity of monolinguals and early bilinguals to language-specific cues, suggesting that the early bilinguals’ exposure to Spanish did not fundamentally change their representations of English phonology. However, neither did the early bilinguals show more sensitivity than the monolinguals to Spanish sounds. The late bilinguals however, were significantly more accurate than either of the other groups. These findings indicate that listeners with varying exposure to English and Spanish are able to use language-specific cues in a nonce-word language categorization task. Differences in how, and not only when, a language was acquired may influence listener sensitivity to more difficult cues, and the advantage for phonemic cues may reflect the greater salience of categories unique to each language. Implications for foreign-accent categorization and cross-language speech perception are discussed, and future directions are outlined to better understand how salience varies across language-specific phonemic and phonetic cues.

Speech perception in noise for bilingual listeners with normal hearing

Objective: The purpose of this study was to determine if speech-in-noise ability, as measured by SNR-50 and SNR loss in bilingual Spanish listeners with normal hearing, was affected by test difficulty. Design: Quasi-experimental, non-randomized intervention study. Study sample: Two groups of adult listeners participated: monolingual English listeners with normal hearing (N = 12) and bilingual Spanish listeners with normal hearing who were proficient in English (N = 10). The quick speech-in-noise (QuickSIN), the Bamford-Kowal-Bench speech-in-noise (BKB-SIN), and the words-in-noise (WIN) tests were used to assess signal-to-noise ratio (SNR) loss and SNR-50 for both groups. Results: Despite the fact that the bilinguals had normal hearing and were proficient in English, each of the speech-in-noise tests evaluated indicated the Spanish listeners had measurable SNR loss and higher than normal SNR-50s. Performance on the BKB-SIN was best for both groups, indicating test difficulty had a significant impact on speech perception in noise. Conclusions: Bilingual Spanish listeners with normal hearing exhibited a mild SNR loss comparable to that observed for a person with hearing loss. This decreased performance in noise requires an improved SNR for this population to reach a comparable level of comprehension to their monolingual English counterparts.

Language mode effects on second language categorical perception

This study investigates the perception of the /b/-/p/ voicing contrast in English and Spanish by native English listeners, native Spanish listeners, and highly proficient Spanish-speaking second-language (L2) learners of English with a late onset of acquisition (mean = 10.8) and at least three-year residence in an English-speaking environment. Participants completed a forced-choice identification task where they identified target syllables in a Voice Onset Time (VOT) continuum as "pi" or "bi." They listened to 10 blocks of 19 equidistant steps ranging from + 88 ms-VOT to -89 ms-VOT. Between blocks, subjects read and wrote responses to language background questions, thus actively processing the target language. Monolinguals completed the task in their native language (L1). L2 learners completed the task once in their L1 and once in their L2, thus providing a manipulation of "language mode" (Grosjean, 2001). The results showed that L2 learners’ category boundary in English did not differ from that of monolingual English listeners, but their category boundary in Spanish differed from that of monolingual Spanish listeners and from their own category boundary in English. These results suggest that the language mode manipulation was successful and that L2 learners can develop new phonetic categories, but this may have an impact on their L1 categories.