Acoustic Salience Research Articles

Extensive residence in a second language environment modifies perceptual strategies for suprasegmental categorization.

Languages differ in the importance of acoustic dimensions for speech categorization. This poses a potential challenge for second language (L2) learners, and the extent to which adult L2 learners can acquire new perceptual strategies for speech categorization remains unclear. This study investigated the effects of extensive English L2 immersion on speech perception strategies and dimension-selective-attention ability in native Mandarin speakers. Experienced first language (L1) Mandarin speakers (length of U.K. residence > 3 years) demonstrated more native-like weighting of cues to L2 suprasegmental categorization relative to inexperienced Mandarin speakers (length of residence < 1 year), weighting duration more highly. However, both the experienced and the inexperienced Mandarin speakers continued to weight duration less highly and pitch more highly during musical beat categorization and struggled to ignore pitch and selectively attend to amplitude in speech, relative to native English speakers. These results suggest that adult L2 experience can lead to retuning of perceptual strategies in specific contexts, but global acoustic salience is more resistant to change. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Factors that moderate global similarity in initial L3 transfer

Abstract Much of the formal linguistic research on third language (L3) acquisition has focused on transfer source selection, with the overall finding that (global) structural similarity between the L1/L2 and L3 is the strongest predictor of initial transfer patterns. Recently, Cabrelli and Pichan (2021) reported data from the production of underlyingly intervocalic voiced stops in L3 Brazilian Portuguese (BP) and L3 Italian that highlight the notion that global similarity is likely moderated by other factors. Specifically, data from heritage Spanish/English bilinguals learning L3 BP reflected reliance on (non-facilitative, but globally more similar) Spanish, while L3 Italian data reflected greater reliance on (facilitative, but globally less similar) English. The current study is a first step towards identifying the source(s) of the disparity, in which we examine the roles of degree of dominance and explicit knowledge in heritage Spanish/English bilinguals. Thirty-four L3 Italian learners completed a delayed repetition task in all three languages. We report English-like patterns that contradict the L3 BP data and cannot be accounted for by degree of dominance or explicit knowledge. We connect these results to existing L3 transfer accounts and the need for further consideration of linguistic and methodological variables, particularly acoustic salience in L3 input and task modality.

Audio-visual clear speech: Articulation, acoustics and perception of segments and tones

Research has established that clear speech with enhanced acoustic signal benefits segmental intelligibility. Less attention has been paid to visible articulatory correlates of clear-speech modifications, or to clear-speech effects at the suprasegmental level (e.g., lexical tone). Questions thus arise as to the extent to which clear-speech cues are beneficial in different input modalities and linguistic domains, and how different resources are incorporated. These questions address the fundamental argument in clear-speech research with respect to the trade-off between effects of signal-based phoneme-extrinsic modifications to strengthen overall acoustic salience versus code-based phoneme-specific modifications to maintain phonemic distinctions. In this talk, we report findings from our studies on audio-visual clear speech production and perception, including vowels and fricatives differing in auditory and visual saliency, and lexical tones believed to lack visual distinctiveness. In a 3-stream study, we use computer-vision techniques to extract visible facial cues associated with segmental and tonal productions in plain and clear speech, characterize distinctive acoustic features across speech styles, and compare audio-visual plain and clear speech perception. Findings are discussed in terms of how speakers and perceivers strike a balance between utilizing general saliency-enhancing and category-specific cues across audio-visual modalities and speech styles with the aim of improving intelligibility.

Production and perception of novel consonant clusters

The present study details a visual world paradigm eye tracking experiment on perception and production of novel consonant clusters. The clusters varied in difficulty based on sonority or perceptual salience scales. During the familiarization phase, listeners heard and watched a story on-screen and produced the names of novel creatures and objects. Each story focused on one cluster. Four creatures/objects were introduced corresponding to the (1) target cluster (e.g., [dlɑpɹ]), (2) epenthesized cluster competitor (e.g., [dəlɑkn]), (3) first cluster consonant (e.g., donkey), and (4) second cluster consonant (e.g., lollipop). During each trial, participants verbally identified one of the four creatures/objects, and their gaze was tracked. We analyzed the productions and gazes to investigate the relative difficulty of producing and perceiving the consonant clusters. We predicted participants would (1) correctly produce/perceive a cluster, (2) epenthesize a vowel/perceive vowel epenethesis, or (3) perceive/produce only one of the cluster sounds. We statistically analyzed the participants’ propensity toward each behavior in both production and perception. As part of the analysis, we examined whether participant behavior was better predicted by analyzing the clusters with the sonority sequencing principle or in terms of acoustic salience and cue recoverability.

A Voz do Brasil: Radio, Salience, and Resilience

To make itself heard, the state relies on instruments of acoustic salience. The purpose of those instruments is to realign a hearing community. In this article, I examine the radio program A Voz do Brasil (The Voice of Brazil) as an instrument of acoustic salience. Produced by the government and focused on the government, the daily one-hour program is mandatory for all radio stations: those that refuse to air it can be fined or suspended. Most Brazilians find the show unappealing, despite attempts from various administrations to “modernize” its form and content. How has A Voz do Brasil remained on air since its creation in the 1930s despite the lack of audience? In following the program’s trajectory during the Vargas Era (1930–45), the Fourth Republic (1945–64), the Military Dictatorship (1964–85), and the New Republic (1985-present), I show how acoustic salience has been overtaken by governmental resilience.

Specificity of Affective Responses in Misophonia Depends on Trigger Identification.

Individuals with misophonia, a disorder involving extreme sound sensitivity, report significant anger, disgust, and anxiety in response to select but usually common sounds. While estimates of prevalence within certain populations such as college students have approached 20%, it is currently unknown what percentage of people experience misophonic responses to such “trigger” sounds. Furthermore, there is little understanding of the fundamental processes involved. In this study, we aimed to characterize the distribution of misophonic symptoms in a general population, as well as clarify whether the aversive emotional responses to trigger sounds are partly caused by acoustic salience of the sound itself, or by recognition of the sound. Using multi-talker babble as masking noise to decrease participants' ability to identify sounds, we assessed how identification of common trigger sounds related to subjective emotional responses in 300 adults who participated in an online study. Participants were asked to listen to and identify neutral, unpleasant and trigger sounds embedded in different levels of the masking noise (signal-to-noise ratios: −30, −20, −10, 0, +10 dB), and then to evaluate their subjective judgment of the sounds (pleasantness) and emotional reactions to them (anxiety, anger, and disgust). Using participants' scores on a scale quantifying misophonia sensitivity, we selected the top and bottom 20% scorers from the distribution to form a Most-Misophonic subgroup (N = 66) and Least-Misophonic subgroup (N = 68). Both groups were better at identifying triggers than unpleasant sounds, which themselves were identified better than neutral sounds. Both groups also recognized the aversiveness of the unpleasant and trigger sounds, yet for the Most-Misophonic group, there was a greater increase in subjective ratings of negative emotions once the sounds became identifiable, especially for trigger sounds. These results highlight the heightened salience of trigger sounds, but furthermore suggest that learning and higher-order evaluation of sounds play an important role in misophonia.

Acoustic salience in the evaluations of intelligibility and foreign accentedness of nonnative vowel production

The study investigates the relative weighting of spectral and temporal acoustic cues in native speakers’ (NS) perception of vowels produced by nonnative speakers (NNS). Acoustic measurements were taken of the spectral and temporal properties of vowels produced by Chinese L2 speakers of English, and by native speakers of American English and British English, who were recruited to pronounce monosyllabic words containing 18 monophthongs and diphthongs in English. In the perception experiment, 25 native English speakers (16 American and 9 British) provided evaluations of intelligibility and ratings of foreign accentedness of the non-native vowels. A correlation analysis was conducted between the NS perception results and the acoustic computation of the NNS production data. The results show that spectral properties of vowels are significantly related to both American and British speakers’ evaluation of English vowels produced by Chinese L2 speakers, whereas the temporal information has no significant correlation to NS perceptual evaluations. The correlation between acoustic measurements and perceptual evaluations confirms that the most significant acoustic cue of English vowels is spectral rather than temporal information in perception.

Acoustic salience in emotional voice perception and its relationship with hallucination proneness.

Auditory verbal hallucinations (AVH) are reported in approximately 70% of psychotic patients, but they also may occur in approximately 10% of the healthy general population. AVH have been related to altered processing of vocal emotions at both sensory and higher-order processing stages in psychotic patients. However, it remains to be clarified whether individuals with high hallucination proneness (HP) exhibit a similar pattern of alterations. We investigated the impact of HP on vocal emotional perception and specified whether manipulations of acoustic cues, such as sound intensity and duration, related to salience changes, affect the time course of voice processing reflected in event-related potentials (ERP) of the electroencephalogram. Participants varying in HP performed a task involving the categorization of emotional nonverbal vocalizations (neutral, anger, and amusement) differing in duration and intensity. ERP results demonstrated interactive effects of HP, valence, and acoustic cues on both early (N1, P2) and late (Late Positive Potential [LPP]) processing stages. Higher HP was associated with decreased N1 and increased P2 amplitudes in response to louder and longer neutral (vs. positive) vocalizations, as well as with a larger LPP to louder and longer negative (vs. neutral) vocalizations. These findings suggest that HP is associated with changes in the processing of vocal emotions that might be related to altered salience of acoustic representations of emotions. Consistent with prior studies with psychotic patients, these findings show that altered perception of vocal emotions may additionally contribute to the experience of hallucinations in nonclinical samples.

Dynamic acoustic salience evokes motor responses

Audio-motor integration is currently viewed as a predictive process in which the brain simulates upcoming sounds based on voluntary actions. This perspective does not consider how our auditory environment may trigger involuntary action in the absence of prediction. We address this issue by examining the relationship between acoustic salience and involuntary motor responses. We investigate how acoustic features in music contribute to the perception of salience, and whether those features trigger involuntary peripheral motor responses. Participants with little-to-no musical training listened to musical excerpts once while remaining still during the recording of their muscle activity with surface electromyography (sEMG), and again while they continuously rated perceived salience within the music using a slider. We show cross-correlations between 1) salience ratings and acoustic features, 2) acoustic features and spontaneous muscle activity, and 3) salience ratings and spontaneous muscle activity. Amplitude, intensity, and spectral centroid were perceived as the most salient features in music, and fluctuations in these features evoked involuntary peripheral muscle responses. Our results suggest an involuntary mechanism for audio-motor integration, which may rely on brainstem-spinal or brainstem-cerebellar-spinal pathways. Based on these results, we argue that a new framework is needed to explain the full range of human sensorimotor capabilities. This goal can be achieved by considering how predictive and reactive audio-motor integration mechanisms could operate independently or interactively to optimize human behavior.

Evidence of Vowel Discrimination Provided by the Acoustic Change Complex.

The objectives of this study were to measure the effects of level and vowel contrast on the latencies and amplitudes of acoustic change complex (ACC) in the mature auditory system. This was done to establish how the ACC in healthy young adults is affected by these stimulus parameters that could then be used to inform translation of the ACC into a clinical measure for the pediatric population. Another aim was to demonstrate that a normalized amplitude metric, calculated by dividing the ACC amplitude in the vowel contrast condition by the ACC amplitude obtained in a control condition (no vowel change) would demonstrate good sensitivity with respect to perceptual measures of vowel-contrast detection. The premises underlying this research were that: (1) ACC latencies and amplitudes would vary with level, in keeping with principles of an increase in neural synchrony and activity that takes place as a function of increasing stimulus level; (2) ACC latencies and amplitudes would vary with vowel contrast, because cortical auditory evoked potentials are known to be sensitive to the spectro-temporal characteristics of speech. Nineteen adults, 14 of them female, with a mean age of 24.2 years (range 20 to 38 years) participated in this study. All had normal-hearing thresholds. Cortical auditory evoked potentials were obtained from all participants in response to synthesized vowel tokens (/a/, /i/, /o/, /u/), presented in a quasi-steady state fashion at a rate of 2/sec in an oddball stimulus paradigm, with a 25% probability of the deviant stimulus. The ACC was obtained in response to the deviant stimulus. All combinations of vowel tokens were tested at 2 stimulus levels: 40 and 70 dBA. In addition, listeners were tested for their ability to detect the vowel contrasts using behavioral methods. ACC amplitude varied systematically with level, and test condition (control versus contrast) and vowel token, but ACC latency did not. ACC amplitudes were significantly larger when tested at 70 dBA compared with 40 dBA and for contrast trials compared with control trials at both levels. Amplitude ratios (normalized amplitudes) were largest for contrast pairs in which /a/ was the standard token. The amplitude ratio metric at the individual level demonstrated up to 97% sensitivity with respect to perceptual measures of discrimination. The present study establishes the effects of stimulus level and vowel type on the latency and amplitude of the ACC in the young adult auditory system and supports the amplitude ratio as a sensitive metric for cortical acoustic salience of vowel spectral features. Next steps are to evaluate these methods in infants and children with hearing loss with the long-term goal of its translation into a clinical method for estimating speech feature discrimination.

Pitch, Timbre and Intensity Interdependently Modulate Neural Responses to Salient Sounds

As we listen to everyday sounds, auditory perception is heavily shaped by interactions between acoustic attributes such as pitch, timbre and intensity; though it is not clear how such interactions affect judgments of acoustic salience in dynamic soundscapes. Salience perception is believed to rely on an internal brain model that tracks the evolution of acoustic characteristics of a scene and flags events that do not fit this model as salient. The current study explores how the interdependency between attributes of dynamic scenes affects the neural representation of this internal model and shapes encoding of salient events. Specifically, the study examines how deviations along combinations of acoustic attributes interact to modulate brain responses, and subsequently guide perception of certain sound events as salient given their context. Human volunteers have their attention focused on a visual task and ignore acoustic melodies playing in the background while their brain activity using electroencephalography is recorded. Ambient sounds consist of musical melodies with probabilistically-varying acoustic attributes. Salient notes embedded in these scenes deviate from the melody’s statistical distribution along pitch, timbre and/or intensity. Recordings of brain responses to salient notes reveal that neural power in response to the melodic rhythm as well as cross-trial phase alignment in the theta band are modulated by degree of salience of the notes, estimated across all acoustic attributes given their probabilistic context. These neural nonlinear effects across attributes strongly parallel behavioral nonlinear interactions observed in perceptual judgments of auditory salience using similar dynamic melodies; suggesting a neural underpinning of nonlinear interactions that underlie salience perception.

Chinese-English Speakers' Perception of Pitch in Their Non-Tonal Language: Reinterpreting English as a Tonal-Like Language.

Changing the F0-contour of English words does not change their lexical meaning. However, it changes the meaning in tonal languages such as Mandarin. Given this important difference and knowing that words in the two languages of a bilingual lexicon interact, the question arises as to how Mandarin-English speakers process pitch in their bilingual lexicon. The few studies that addressed this question showed that Mandarin-English speakers did not perceive pitch in English words as native English speakers did. These studies, however, used English words as stimuli failing to examine nonwords and Mandarin words. Consequently, possible pre-lexical effects and L1 transfer were not ruled out. The present study fills this gap by examining pitch perception in Mandarin and English words and nonwords by Mandarin-English speakers and a group of native English controls. Results showed the tonal experience of Chinese-English speakers modulated their perception of pitch in their non-tonal language at both pre-lexical and lexical levels. In comparison to native English controls, tonal speakers were more sensitive to the acoustic salience of F0-contours in the pre-lexical processing due to top-down feedback. At the lexical level, Mandarin-English speakers organized words in their two languages according to similarity criteria based on both F0 and segmental information, whereas only the segmental information was relevant to the control group. These results in perception together with consistently reported production patterns in previous literature suggest that Mandarin-English speakers process pitch in English as if it was a one-tone language.

A WASN-Based Suburban Dataset for Anomalous Noise Event Detection on Dynamic Road-Traffic Noise Mapping.

Traffic noise is presently considered one of the main pollutants in urban and suburban areas. Several recent technological advances have allowed a step forward in the dynamic computation of road-traffic noise levels by means of a Wireless Acoustic Sensor Network (WASN) through the collection of measurements in real-operation environments. In the framework of the LIFE DYNAMAP project, two WASNs have been deployed in two pilot areas: one in the city of Milan, as an urban environment, and another around the city of Rome in a suburban location. For a correct evaluation of the noise level generated by road infrastructures, all Anomalous Noise Events (ANE) unrelated to regular road-traffic noise (e.g., sirens, horns, speech, etc.) should be removed before updating corresponding noise maps. This work presents the production and analysis of a real-operation environmental audio database collected through the 19-node WASN of a suburban area. A total of 156 h and 20 min of labeled audio data has been obtained differentiating among road-traffic noise and ANEs (classified in 16 subcategories). After delimiting their boundaries manually, the acoustic salience of the ANE samples is automatically computed as a contextual Signal-to-Noise Ratio (SNR) together with its impact on the A-weighted equivalent level (). The analysis of the real-operation WASN-based environmental database is evaluated with these metrics, and we conclude that the 19 locations of the network present substantial differences in the occurrences of the subcategories of ANE, with a clear predominance of the noise of sirens, trains, and thunder.

Fourteen-month-olds' sensitivity to acoustic salience in minimal pair word learning.

During the first two years of life, infants concurrently refine native-language speech categories and word learning skills. However, in the Switch Task, 14-month-olds do not detect minimal contrasts in a novel object-word pairing (Stager & Werker, 1997). We investigate whether presenting infants with acoustically salient contrasts (liquids) facilitates success in the Switch Task. The first two experiments demonstrate that acoustic differences boost infants' detection of contrasts. However, infants cannot detect the contrast when the segments are digitally shortened. Thus, not all minimal contrasts are equally difficult, and the acoustic properties of a contrast matter in word learning.

Geminate attrition across three generations of Farsi-English bilinguals living in Canada: An acoustic Study

The main goal of this study was to determine whether the geminate-singleton consonant length contrast attrites across three different generations of Farsi-English-speaking bilinguals living in Canada. The secondary aim of the study was to shed light on the role of universal phonetic factors on the process of geminate-singleton length contrast attrition in the same population. The effect of manner/class of sounds and voicing were examined as predictors of geminate attrition in eight Farsi-English-speaking bilinguals living in Toronto forming three categories of generations: first generation, 1.5 generation and second generation. The inclusion of the 1.5 generation category is novel and it refers to children of immigrants who came to Canada between the ages of five to fourteen. The productions of the bilinguals were compared with the productions of three homeland variety controls. A word-naming task, which included 108 words was conducted. 2398 tokens were analyzed acoustically using PRAAT. Attrition was defined in terms of changes in mean duration of geminates relative to their singleton counter-parts and percentage geminate-singleton degemination/category overlap. Mean durations were then analyzed using a 3-way, mixed-model, repeated-measures ANOVA. Results showed that geminates attrite across different successive generations. Moreover, there was some evidence to suggest that geminate realization across generations patterns with typological patterns previously reported, showing that universal phonetic principles such as aerodynamic constraints/articulatory difficulty and acoustic salience also constrain geminate realization in bilingual Farsi-English speakers. However, there was no evidence to suggest that more marked geminates suffer a higher degree of attrition. This is the first study to examine the attrition of a typologically marked contrast, which considers the role of universal phonetic principles, markedness in an understudied bilingual community across different generations.

Perception of Similar and Dissimilar Lexical Tones by Non‐Tone‐Learning Infants

This study examined the perception of Mandarin lexical tones by non‐tone‐learning infants. We tested French‐learning 4‐, 8‐, and 11‐month‐olds on Tone 2 (rising) versus Tone 3 (dipping), the most acoustically similar contrast in Mandarin, and on Tone 1 (high) versus Tone 4 (falling), acoustically more dissimilar contrast. We hypothesized that sensitivity should decline with age for the similar contrast, and the dissimilar contrast should remain more discriminable. Infants were habituated to one tone and tested with the same tone versus the contrastive tone. Results showed that the dissimilar T1–T4 contrast was consistently discriminated by all three ages, whereas the discrimination of the similar T2–T3 contrast revealed a tendency to decline over the ages. These results suggest that relative to consonants and vowels, perceptual sensitivity to lexical tones remains stronger in non‐tone‐learning infants. Discrimination of lexical tones is affected by both acoustic salience and perceptual attunement to the native‐language phonology.

No perceptual reorganization for Limburgian tones? A cross-linguistic investigation with 6- to 12-month-old infants.

Despite the fact that many of the world's languages use lexical tone, the majority of language acquisition studies has focused on non-tone languages. Research on tone languages has typically investigated well-known tone languages such as Mandarin and Cantonese Chinese. The current study looked at a Limburgian dialect of Dutch that uses lexical pitch differences, albeit in a rather restricted way. Using a visual habituation paradigm, 6- to 12-month-old Limburgian and Dutch infants were tested for their ability to discriminate Limburgian tones. The results showed that both Limburgian and Dutch infants discriminate the Limburgian tones throughout their first year of life. The role of linguistic experience, acoustic salience, and the degree of similarity to the native prosodic system are discussed.

Description of Anomalous Noise Events for Reliable Dynamic Traffic Noise Mapping in Real-Life Urban and Suburban Soundscapes

Traffic noise is one of the main pollutants in urban and suburban areas. European authorities have driven several initiatives to study, prevent and reduce the effects of exposure of population to traffic. Recent technological advances have allowed the dynamic computation of noise levels by means of Wireless Acoustic Sensor Networks (WASN) such as that developed within the European LIFE DYNAMAP project. Those WASN should be capable of detecting and discarding non-desired sound sources from road traffic noise, denoted as anomalous noise events (ANE), in order to generate reliable noise level maps. Due to the local, occasional and diverse nature of ANE, some works have opted to artificially build ANE databases at the cost of misrepresentation. This work presents the production and analysis of a real-life environmental audio database in two urban and suburban areas specifically conceived for anomalous noise events’ collection. A total of 9 h 8 min of labelled audio data is obtained differentiating among road traffic noise, background city noise and ANE. After delimiting their boundaries manually, the acoustic salience of the ANE samples is automatically computed as a contextual signal-to-noise ratio (SNR). The analysis of the real-life environmental database shows high diversity of ANEs in terms of occurrences, durations and SNRs, as well as confirming both the expected differences between the urban and suburban soundscapes in terms of occurrences and SNRs, and the rare nature of ANE.

Enhanced music sensitivity in 9-month-old bilingual infants

This study explores the influence of bilingualism on the cognitive processing of language and music. Specifically, we investigate how infants learning a non-tone language perceive linguistic and musical pitch and how bilingualism affects cross-domain pitch perception. Dutch monolingual and bilingual infants of 8–9 months participated in the study. All infants had Dutch as one of the first languages. The other first languages, varying among bilingual families, were not tone or pitch accent languages. In two experiments, infants were tested on the discrimination of a lexical (N = 42) or a violin (N = 48) pitch contrast via a visual habituation paradigm. The two contrasts shared identical pitch contours but differed in timbre. Non-tone language learning infants did not discriminate the lexical contrast regardless of their ambient language environment. When perceiving the violin contrast, bilingual but not monolingual infants demonstrated robust discrimination. We attribute bilingual infants’ heightened sensitivity in the musical domain to the enhanced acoustic sensitivity stemming from a bilingual environment. The distinct perceptual patterns between language and music and the influence of acoustic salience on perception suggest processing diversion and association in the first year of life. Results indicate that the perception of music may entail both shared neural network with language processing, and unique neural network that is distinct from other cognitive functions.

Production and perception of clear speech

When talkers are aware of listeners’ speech perception difficulties due to hearing loss, noise, or a language barrier, they typically adopt an intelligibility-enhancing speaking style known as “clear speech.” To the extent that clear speech is more intelligible than “conversational speech,” a cross-style acoustic-phonetic comparison provides information about factors that affect speech intelligibility. I will present data from a project that tested the hypothesis that clear speech is guided by both universal, auditory-perceptual factors and language-specific, structural factors. The former serve to enhance the overall acoustic salience of the speech signal such that it is more resistant to the adverse effects of noise or listener-related perceptual deficits; the latter serves to enhance the realization of phonological contrasts. This hypothesis predicts that clear speech production shows predictable and systematic cross-language similarities and differences, and that the clear speech intelligibility benefit is modulated by the listeners’ experience with the target language. To address these predictions, we present data from a cross-language comparison of clear speech production and a cross-population comparison of clear speech perception. These studies provide fundamental information about variability in speech intelligibility which may ultimately lead to effective, efficient, and listener-specific speech intelligibility enhancement strategies.