Perceptual restoration of locally time-reversed speech: Non-native listeners’ performance in their L2 vs. L1

Nonnative listeners are generally not as good as native listeners in perceptually restoring degraded speech and understand what was being said. The current study investigates how nonnative listeners of English (namely, native Japanese speakers who learned English as a second language) perceptually restore temporally distorted speech in their L2 English as compared with native English listeners (L1 English) reported in Ishida et al. (Cognition, 151, 68–75, 2016), and as compared with the listeners’ native tongue (L1 Japanese). In the experiment, listeners listened to locally time-reversed words and pseudowords in their L2 English and L1 Japanese where every 10, 30, 50, 70, 90, or 110 ms of speech signal was flipped in time—these stimuli contained either many fricatives or stops. The results suggested that the intelligibility of locally time-reversed words and pseudowords deteriorated as the length of reversed segments increased in both listeners’ L2 English and L1 Japanese, while listeners understood locally time-reversed speech more in their L1 Japanese. In addition, lexical context supported perceptual restoration in both listeners’ L1 Japanese and L2 English, while phonemic constituents affected perceptual restoration significantly only in listeners’ L1. On the other hand, locally time-reversed words and pseudowords in L1 Japanese were much more intelligible than those in L1 English reported in Ishida et al. It is possible that the intelligibility of temporally distorted lexical items depends on the structure of basic linguistic units in each language, and the Japanese language might have a unique characteristic because of its CV and V structure.

Listening Effort by Native and Nonnative Listeners Due to Noise, Reverberation, and Talker Foreign Accent During English Speech Perception

Purpose Understanding speech in complex realistic acoustic environments requires effort. In everyday listening situations, speech quality is often degraded due to adverse acoustics, such as excessive background noise level (BNL) and reverberation time (RT), or talker characteristics such as foreign accent ( Mattys, Davis, Bradlow, & Scott, 2012 ). In addition to factors affecting the quality of the input acoustic signals, listeners' individual characteristics such as language abilities can also make it more difficult and effortful to understand speech. Based on the Framework for Understanding Effortful Listening ( Pichora-Fuller et al., 2016 ), factors such as adverse acoustics, talker accent, and listener language abilities can all contribute to increasing listening effort. In this study, using both a dual-task paradigm and a self-report questionnaire, we seek to understand listening effort in a wide range of realistic classroom acoustic conditions as well as varying talker accent and listener English proficiency. Method One hundred fifteen native and nonnative adult listeners with normal hearing were tested in a dual task of speech comprehension and adaptive pursuit rotor (APR) under 15 acoustic conditions from combinations of BNLs and RTs. Listeners provided responses on the NASA Task Load Index (TLX) questionnaire immediately after completing the dual task under each acoustic condition. The NASA TLX surveyed 6 dimensions of perceived listening effort: mental demand, physical demand, temporal demand, effort, frustration, and perceived performance. Fifty-six listeners were tested with speech produced by native American English talkers; the other 59 listeners, with speech from native Mandarin Chinese talkers. Based on their 1st language learned during childhood, 3 groups of listeners were recruited: listeners who were native English speakers, native Mandarin Chinese speakers, and native speakers of other languages (e.g., Hindu, Korean, and Portuguese). Results Listening effort was measured objectively through the APR task performance and subjectively using the NASA TLX questionnaire. Performance on the APR task did not vary with changing acoustic conditions, but it did suggest increased listening effort for native listeners of other languages compared to the 2 other listener groups. From the NASA TLX, listeners reported feeling more frustrated and less successful in understanding Chinese-accented speech. Nonnative listeners reported more listening effort (i.e., physical demand, temporal demand, and effort) than native listeners in speech comprehension under adverse acoustics. When listeners' English proficiency was controlled, higher BNL was strongly related to a decrease in perceived performance, whereas such relationship with RT was much weaker. Nonnative listeners who shared the foreign talkers' accent reported no change in listening effort, whereas other listeners reported more difficulty in understanding the accented speech. Conclusions Adverse acoustics required more effortful listening as measured subjectively with a self-report NASA TLX. This subjective scale was more sensitive than a dual task that involved speech comprehension, which was beyond sentence recall. It was better at capturing the negative impacts on listening effort from acoustic factors (i.e., both BNL and RT), talker accent, and listener language abilities.

Native and Non-Native Listeners Perceptual Judgement of English Accentedness, Intelligibility, and Acceptability of Indonesian Speakers

This research aimed at investigating the extent of accentedness and intelligibility as well as the acceptability of Indonesian foreign-accented speech perceived by native and non-native listeners, as well as finding their correlation to each other. It used qualitative research. The participant of the research was selected using purposive sampling. The participants were divided into speakers and listeners. There are six speakers and four listeners selected. The four listeners were native and nonnative listeners who rated and transcribed six recorded reading of Indonesian speakers by means of SPIN (Speech Perception in Noise) test. The results show that native listeners rate the speech almost the same way as non-native listeners do. The speeches with clear and accurate pronunciation are rated highly accepted and fully intelligible, regardless of having a very strong accent. In contrast, less clear and accurate pronunciations, as well as a very strong accent of the speeches, are rated unacceptable and still reasonably intelligible. The result of the correlation test between accentedness and intelligibility as well as accentedness and acceptability of the accent finds on no account of correlation to each other. Therefore, accentedness and intelligibility plus accentedness and acceptability of the accent are independent, so that strong foreign accent could stay acceptable and intelligible. The factors found to influence the judgment are the familiarity of the accent, clarity, and accuracy of pronunciation. Aforementioned findings have implication to challenge English teachers in Indonesia to develop meaningful activities to teach English pronunciation accurately to be regarded as fully intelligible and acceptable by listeners, especially native English listeners.

Dialect comprehension and identification in L2 Spanish: Familiarity and type of exposure

Previous work has shown that both native and nonnative listeners’ production and perception of regional variation changes with an individual’s residential history, social ties, and exposure to different dialects. The present study investigates the relationship between L2 learners’ dialect familiarity and their ability to understand and identify regional varieties in the read speech of native speakers from six different regions. The source and depth of participants’ past dialect exposure, as well as a measure of their proficiency in Spanish, were also accounted for in this investigation of 60 L1 English speakers’ performance on a transcription task and a dialect identification task. Results revealed that familiarity was a significant predictor of learners’ dialect identification regardless of level, and it also predicted the dialect comprehension of more advanced students. Comprehension but not identification was also more accurate when multiple types of exposure were reported and when exposure was through native instructors, study abroad, and media from a specific region. Ultimately, the present findings shed light on second language learners’ comprehension and identification of different regional varieties of Spanish with and without prior exposure to each dialect, including the effects of different sources of exposure on participants’ perception.

Shedding New Light on the Evaluation of Accented Speakers: Basic Mechanisms Behind Nonnative Listeners’ Evaluations of Nonnative Accented Job Candidates

The present research unites two emergent trends in the area of language attitudes: (a) research on perceptions of nonnative speakers by nonnative listeners and (b) the search for general, basic mechanisms underlying the evaluation of nonnative accented speakers. In three experiments featuring an employment situation, German participants listened to a presentation given in English by a German speaker with a strong versus native-like accent (in Studies 1–3) versus a native speaker of English (in Study 1). They evaluated candidates with a strong accent worse than candidates with a native(-like) pronunciation—even to the degree that the quality of arguments was of no relevance (Study 1). Study 2 introduces an effective intervention to reduce these discriminatory tendencies. Across studies, affect and competence emerged as major mediators of hirability evaluations. Study 3 further revealed sequential indirect influences, which advance our understanding of previous inconsistent findings regarding disfluency and warmth perceptions.

Directional Asymmetries in Vowel Perception of Adult Nonnative Listeners Do Not Change Over Time With Language Experience

Purpose This study tested an assumption of the Natural Referent Vowel (Polka & Bohn, 2011) framework, namely, that directional asymmetries in adult vowel perception can be influenced by language experience. Method Data from participants reported in Escudero and Williams (2014) were analyzed. Spanish participants categorized the Dutch vowels /aː/ and /ɑ/ in 2 separate sessions: before and after vowel distributional training. Sessions were 12 months apart. Categorization was assessed using the XAB task, where on each trial participants heard 3 sounds sequentially (first X, then A, then B) and had to decide whether X was more similar to A or B. Results Before training, participants exhibited a directional asymmetry in line with the prediction of Natural Referent Vowel. Specifically, Spanish listeners performed worse when the vowel change from X to A was a change from peripheral to central vowel (/ɑ/ to /aː/). However, this asymmetry was maintained 12 months later, even though distributional training improved vowel categorization performance. Conclusions Improvements in adult nonnative vowel categorization accuracy are not explained by attenuation of directional asymmetries. Directional asymmetries in vowel perception are altered during native language acquisition, but may possibly be impervious to nonnative language experiences in adulthood.