Processing Of Acoustic Information Research Articles

Ear Asymmetry and Contextual Influences on Speech Perception in Hearing-Impaired Patients

The left hemisphere preference for verbal stimuli is well known, with a right ear (RE) advantage obtained when competing verbal stimuli are presented simultaneously, at comfortable intensities, to both ears. Speech perception involves not only the processing of acoustic peripheral information but also top–down contextual influences, filling the gaps in the incoming information that is particularly degraded in hearing-impaired individuals. This study aimed to analyze the potential asymmetry of those contextual influences on a simple speech perception task in hearing-impaired patients in light of hemispheric asymmetry. Contextual influences on disyllabic word perception scores of 60 hearing-impaired patients were compared between left ear (LE) and RE, in a balanced design, involving two repetitions of the same task. Results showed a significantly greater contextual influence on the RE versus the LE and, for the second repetition versus the first one, without any interaction between the two. Furthermore, the difference in contextual influences between RE and LE increased significantly with the RE advantage measured by a dichotic listening test in the absence of any significant correlation with hearing threshold asymmetry. Lastly, the contextual influence asymmetry decreased significantly as age increased, which was mainly due to a greater increase, with age, of contextual influences on the LE versus the RE. Those results agree with the literature reporting a relative right-shift of hemispheric asymmetry observed with age in speech in noise perception tasks in normal hearing subjects and the clinical reports of generally better audiometric speech scores obtained in RE versus LE.

Effects of M currents on the persistent activity of pyramidal neurons in mouse primary auditory cortex.

Neuronal persistent activity (PA) is a common phenomenon observed in many types of neurons. PA can be induced in neurons in the mouse auditory nucleus by activating cholinergic receptors with carbachol (CCh), a dual muscarinic and nicotinic receptor agonist. PA is presumed to be associated with learning-related auditory plasticity at the cellular level. However, the mechanism is not clearly understood. Many studies have reported that muscarinic receptor agonists inhibit muscarinic-sensitive potassium channels (M channels). Potassium efflux through M channels produces potassium currents, called M currents, that play an essential role in regulating neural excitability and synaptic plasticity. Further study is needed to determine whether M currents affect the PA of auditory central neurons and provide additional analysis of the variations in electrophysiological properties. We used in vitro whole cell patch-clamp recordings in isolated mouse brain slices to investigate the effects of M currents on the PA in pyramidal neurons in layer V of the primary auditory cortex (AI-L5). We found that blocking M currents with XE991 depolarized the AI-L5 pyramidal neurons, which significantly increased the input resistance. The active threshold and threshold intensity were significantly reduced, indicating that intrinsic excitability was enhanced. Our results also showed that blocking M currents with XE991 switched the neuronal firing patterns in the AI-L5 pyramidal neurons from regular spiking to intrinsic bursting. Blocking M currents facilitated PA by increasing the plateau potential and enhancing intrinsic excitability. Our results suggested that blocking M currents might facilitate the PA in AI-L5 pyramidal neurons, which underlies auditory plasticity.NEW & NOTEWORTHY Persistent activity (PA) in AI-L5 pyramidal neurons plays an essential role in acoustic information processing. We used in vitro whole cell patch-clamp recordings to investigate the effects of M currents on the PA in AI-L5 pyramidal neurons. Blocking M currents with XE991 facilitated PA by increasing the plateau potential and enhancing intrinsic excitability, causing the firing patterns of AI-L5 pyramidal neurons to become more bursting. These results provide new insight into our understanding of the cellular mechanisms that govern learning-induced auditory plasticity.

The frequency-following response to assess the neural representation of spectral speech cues in older adults

Older adults often present difficulties understanding speech that cannot be explained by age-related changes in sound audibility. Psychoacoustic and electrophysiologic studies have linked these suprathreshold difficulties to age-related deficits in the auditory processing of temporal and spectral sound information. These studies suggest the existence of an age-related temporal processing deficit in the central auditory system, but the existence of such deficit in the spectral domain remains understudied. The FFR is an electrophysiological evoked response that assesses the ability of the neural auditory system to reproduce the spectral and temporal patterns of a sound. The main goal of this short review is to investigate if the FFR can identify and measure spectral processing deficits in the elderly compared to younger adults (for both, without hearing loss or competing noise). Furthermore, we want to determine what stimuli and analyses have been used in the literature to assess the neural encoding of spectral cues in older adults. Almost all reviewed articles showed an age-related decline in the auditory processing of spectral acoustic information. Even when using different speech and non-speech stimuli, studies reported an age-related decline at the fundamental frequency, at the first formant, and at other harmonic components using different metrics, such as the response's amplitude, inter-trial phase coherence, signal-to-response correlation, and signal-to-noise ratio. These results suggest that older adults may present age-related spectral processing difficulties, but further FFR studies are needed to clarify the effect of advancing age on the neural encoding of spectral speech cues. Spectral processing research on aging would benefit from using a broader variety of stimuli and from rigorously controlling for hearing thresholds even in the absence of disabling hearing loss. Advances in the understanding of the effect of age on FFR measures of spectral encoding could lead to the development of new clinical tools, with possible applications in the field of hearing aid fitting.

Extended topological valley-locked surface acoustic waves

Stable and efficient guided waves are essential for information transmission and processing. Recently, topological valley-contrasting materials in condensed matter systems have been revealed as promising infrastructures for guiding classical waves, for they can provide broadband, non-dispersive and reflection-free electromagnetic/mechanical wave transport with a high degree of freedom. In this work, by designing and manufacturing miniaturized phononic crystals on a semi-infinite substrate, we experimentally realized a valley-locked edge transport for surface acoustic waves (SAWs). Critically, original one-dimensional edge transports could be extended to quasi-two-dimensional ones by doping SAW Dirac “semimetal” layers at the boundaries. We demonstrate that SAWs in the extended topological valley-locked edges are robust against bending and wavelength-scaled defects. Also, this mechanism is configurable and robust depending on the doping, offering various on-chip acoustic manipulation, e.g., SAW routing, focusing, splitting, and converging, all flexible and high-flow. This work may promote future hybrid phononic circuits for acoustic information processing, sensing, and manipulation.

Method of Processing Acoustic Information for Purposes of Monitoring State of Valves of Gas Cleaning Equipment

Method of Processing Acoustic Information for Purposes of Monitoring State of Valves of Gas Cleaning Equipment

Improved Unmanned Aerial Vehicle Noise Direction Finding System

The work is devoted to the development of the acoustic direction of creation of means of detection of unmanned aerial vehicles (UAVs). The work of these tools is based on the principles of noise direction finding with the use of such variable characteristics of the acoustic field as: sound intensity, frequency spectrum and spatial spectrum. The architecture of UAV detection devices on the acoustic field corresponds to the algorithms of reproduction in separate paths of the device of ideology of registration and control of dynamics of change of characteristic of an acoustic field which defines the specified change as the fact of detection. The technical implementation of the above detection devices is to create a path of parallel octave, ½ octave and ⅓ octave filters, a path of narrowband filtering and a path of detection by power (intensity). 
 The ideology of construction of detection devices is based on variability and physical manifestations of changes in such characteristics of acoustic noise as: sound intensity in the space - time interval of observation, broadband filtering, narrowband filtering, correlation characteristics.
 To ensure the detection of acoustic power (or intensity) with subsequent measurement of the level, the counter-inclusion (by switching or using operational amplifiers) of the elements of the cross-shaped group is used. An important and new feature is that one of the linear discrete acoustic antennas with an enlarged base additionally has two more pressure receivers symmetrically relative to the phase center.
 For broadband filtration, a comb of ⅓ octave band and semi-octave filters is used. In turn, the path of the narrowband spectrum is an octave band filter and a unit for calculating the fast Fourier transform.
 The path of the correlation direction-finding method implements the determination of changes in the autocorrelation coefficient and the corresponding electrical parameter (say the current through the display circuit) in the processing path in situations of fixing the direction to the target.
 Therefore, the proposed system for detecting useful noise signals should contain four paths, the physical implementation of detection in which is performed by software implementation of detection algorithms and, threshold processing and indication of results
 In order to improve and increase the reliability of detection, the direction finder is supplemented by the path of detection on the mutual spectrum and the path of the correlation method of direction finding.
 The processing of input acoustic information of the type of specific noise-like signal is carried out by using the instrumental laboratory software package Lab View and Math Lab. We will add that the article contains theoretical and practical results of measurements of noise loading and range of action of a noise direction finder. Experimental studies in terms of detection and measurement of the main characteristics of the device were conducted in laboratory and field conditions.
 At the same time, the present demonstrates the rapid development of the UAV fleet, which determines the urgency of the work and the development of the device as a means of counteracting small aircraft of various recognitions is its goal.

A comparison of Laryngeal effect in the dialects of Punjabi language

Human beings have their own speaking style which helped them in depicting their native language. The major reason behind variability in some language is due to varying dialect of the speakers. In the field of Automatic Speech Recognition (ASR), key challenge is to recognize and to generate an acoustic model which represents differences of redundant acoustic features. In this paper, an issue of dialect classification is perform on the basis of tonal aspects of laryngeal phoneme [h]. This is an empirical study of [h] sound words in four major dialects of Indian Punjabi language with two key parameters, namely F0 variation, and acoustic space, which are calculated using two formant frequencies: F1, and F2. The results are based on four different dialects which provide us some interesting hypotheses and are explored with self-created dataset. The speech analysis tool PRAAT features have been extracted and correlations are studied using Statistical Package for the Social Sciences (SPSS). Each variable has been compared with same variable of all other dialects. The results analysis showed that the fundamental frequency of these vowels are influenced distinctly in different dialectal conditions. Apart F1 and F2 have shown a significant correlation with each spoken dialect. Further work is extended through processing of acoustic information at feature level or by comparing the performance analysis using basic or hybrid Linear Predictive Cepstral Coefficients feature extraction methods. The result shows that the hybrid LPCC + F0 system achieved a Relative Improvement (R.I.) of 6.94% on Subspace Gaussian Mixture Model model in comparison to that of basic LPCC approach respectively.

Effects of Amateur Musical Experience on Categorical Perception of Lexical Tones by Native Chinese Adults: An ERP Study.

Music impacting on speech processing is vividly evidenced in most reports involving professional musicians, while the question of whether the facilitative effects of music are limited to experts or may extend to amateurs remains to be resolved. Previous research has suggested that analogous to language experience, musicianship also modulates lexical tone perception but the influence of amateur musical experience in adulthood is poorly understood. Furthermore, little is known about how acoustic information and phonological information of lexical tones are processed by amateur musicians. This study aimed to provide neural evidence of cortical plasticity by examining categorical perception of lexical tones in Chinese adults with amateur musical experience relative to the non-musician counterparts. Fifteen adult Chinese amateur musicians and an equal number of non-musicians participated in an event-related potential (ERP) experiment. Their mismatch negativities (MMNs) to lexical tones from Mandarin Tone 2–Tone 4 continuum and non-speech tone analogs were measured. It was hypothesized that amateur musicians would exhibit different MMNs to their non-musician counterparts in processing two aspects of information in lexical tones. Results showed that the MMN mean amplitude evoked by within-category deviants was significantly larger for amateur musicians than non-musicians regardless of speech or non-speech condition. This implies the strengthened processing of acoustic information by adult amateur musicians without the need of focused attention, as the detection of subtle acoustic nuances of pitch was measurably improved. In addition, the MMN peak latency elicited by across-category deviants was significantly shorter than that by within-category deviants for both groups, indicative of the earlier processing of phonological information than acoustic information of lexical tones at the pre-attentive stage. The results mentioned above suggest that cortical plasticity can still be induced in adulthood, hence non-musicians should be defined more strictly than before. Besides, the current study enlarges the population demonstrating the beneficial effects of musical experience on perceptual and cognitive functions, namely, the effects of enhanced speech processing from music are not confined to a small group of experts but extend to a large population of amateurs.

Experimental realization of phonon demultiplexing in three-dimensions

Phononic metamaterials enabled the realization of many acoustic components analogous to their electronic counterparts, such as transistors, logic gates, and calculators. A key component among these is the demultiplexer, a device that receives multiple signals and sorts them based on their frequencies into separate channels. Previous experimental realizations of acoustic and elastic multiplexers have employed plates with pillars or holes to demultiplex frequencies. However, existing realizations are confined to two dimensions, which can limit potential acoustic or elastic circuit design. Here, we show an experimental realization of a three-dimensional, four channel phononic demultiplexer. Our design methodology is based on bundles of pass-bands within a large bandgap that can easily be tuned for multi-channel frequency demultiplexing. The proposed design can be utilized in acoustic and elastic information processing, nondestructive evaluation, and communication applications, among others.

Peripheral Anomalies in USH2A Cause Central Auditory Anomalies in a Mouse Model of Usher Syndrome and CAPD.

Central auditory processing disorder (CAPD) is associated with difficulties hearing and processing acoustic information, as well as subsequent impacts on the development of higher-order cognitive processes (i.e., attention and language). Yet CAPD also lacks clear and consistent diagnostic criteria, with widespread clinical disagreement on this matter. As such, identification of biological markers for CAPD would be useful. A recent genome association study identified a potential CAPD risk gene, USH2A. In a homozygous state, this gene is associated with Usher syndrome type 2 (USH2), a recessive disorder resulting in bilateral, high-frequency hearing loss due to atypical cochlear hair cell development. However, children with heterozygous USH2A mutations have also been found to show unexpected low-frequency hearing loss and reduced early vocabulary, contradicting assumptions that the heterozygous (carrier) state is “phenotype free”. Parallel evidence has confirmed that heterozygous Ush2a mutations in a transgenic mouse model also cause low-frequency hearing loss (Perrino et al., 2020). Importantly, these auditory processing anomalies were still evident after covariance for hearing loss, suggesting a CAPD profile. Since usherin anomalies occur in the peripheral cochlea and not central auditory structures, these findings point to upstream developmental feedback effects of peripheral sensory loss on high-level processing characteristic of CAPD. In this study, we aimed to expand upon the mouse behavioral battery used in Perrino et al. (2020) by evaluating central auditory brain structures, including the superior olivary complex (SOC) and medial geniculate nucleus (MGN), in heterozygous and homozygous Ush2a mice. We found that heterozygous Ush2a mice had significantly larger SOC volumes while homozygous Ush2a had significantly smaller SOC volumes. Heterozygous mutations did not affect the MGN; however, homozygous Ush2a mutations resulted in a significant shift towards more smaller neurons. These findings suggest that alterations in cochlear development due to USH2A variation can secondarily impact the development of brain regions important for auditory processing ability.

Интерферометрическая обработка акустической информации с использованием протяженных антенн в диспергирующих средах

The theory of interferometric processing of acoustic information by using extended antennas in media with frequency dispersion is presented. The dependence between the two-dimensional spectral density of the two-fold Fourier transform of the interference pattern formed by a moving noise source and the aperture and angular structure of the received field is analyzed. The gain factor, directivity characteristic, and noise immunity of processing are estimated. Depending between the input signal/noise ratio on the antenna element and the maximal range of the noise source is obtained. This maximal range allows stable detection and estimation of direction, radial velocity, range and depth are close to real values. Numerical simulation results are presented and discussed.

Device profile of the MED-EL cochlear implant system for hearing loss: overview of its safety and efficacy

ABSTRACT Introduction Patients suffering from severe to profound hearing loss or even deafness can achieve a hearing improvement with a cochlear implant (CI) treatment that is significantly higher than the results achieved with conventional hearing aids. The CI system consists of an implantable stimulator, which is inserted retro-auricularly into the mastoid, and an externally worn processor unit, which provides the pickup of sound and processing of acoustic information as well as the power supply for the stimulator and internal current sources. The stimulator has an electrode array that is inserted into the cochlea. Areas covered This is a descriptive overview of MED-EL’s multichannel CI system (MED-EL, Innsbruck, Austria), which was introduced to the European market in 1994. The continuing development of the implant as well as the external components is outlined and various other aspects (stimulation strategy, adaptation, results, reliability) are discussed. Expert commentary The strength of the company is the continuous pursuit of innovative ideas. This is evidenced by numerous innovations. The reliability of the implants has been continuously improved. The current SYNCHRONY models of the manufacturer show no indication of technically caused failures over an observation period of 5 years.

Processamento auditivo central em crianças com disfonia: avaliação comportamental e eletrofisiológica

Introdução: O transtorno do processamento auditivo central pode ocorrer em concomitância com outras alterações, assim como a disfonia. Objetivo: Analisar os resultados obtidos na avaliação do processamento auditivo central em crianças com disfonia. Método: Estudo comparativo e de coorte transversal, constituído por 16 crianças de oito a 11 anos reunidas em dois grupos: o Grupo Estudo composto por sete crianças com disfonia funcional ou organofuncional, e o Grupo Controle por nove crianças sem queixas e alterações vocais. Foram realizados os seguintes procedimentos: anamnese, gravação vocal, avaliação perceptivo-auditiva da voz, laringoscopia, avaliação audiológica básica, avaliação do processamento auditivo por meio de testes comportamentais e eletrofisiológicos. Resultados: Houve diferença estatisticamente significativa entre os grupos para as etapas de atenção direcionada no teste Dicótico não verbal, etapa de humming no Padrão de frequência, limiar de detecção de gap e porcentagem de acertos no Gaps in Noise e para a latência do P300. Conclusão: A partir da análise dos resultados verificou-se que o grupo com disfonia apresentou transtorno do processamento auditivo central com alteração nas habilidades auditivas de figura-fundo para sons não verbais, ordenação e resolução temporal e latência do P300 prolongada, sugerindo também um déficit no processamento cognitivo da informação acústica.

Spatio-temporally modulated composite metamaterials by using switchable mesostructural topology

Spatio-temporally modulated composite metamaterials (STMCMs) possess tunable and nearly “full-banded” asymmetrical elastic wave properties, making them highly promising for uses in a wide range of applications, such as cloaking, acoustic information processing, ideal vibration isolation, ultrasonic technology. Despite much progress made in the structural design and fabrication of intelligent materials, the realization of STMCMs for practical fabrication is still an open issue because of a series of challenges existing in the rational design of the spatial and temporal ordered structures. In this work, we propose an implementation scheme for a laminated STMCM and computationally predict its performance. The elementary structure of the laminated STMCM is constructed by a functional component named as “acoustic switch” that endows the material with spatio-temporally modulated mesostructural topology and properties. This work not only provides a practical implementation scheme for experimental realization of the STMCMs, but also improves the understanding of STMCMs.

Audiological Research Methods in the Diagnosis of Postoperative Cognitive Dysfunction

Introduction. faring loss may be a predictor or a kind of catalyst for cognitive disorders. This may indicate that audiological research methods can take their place in the diagnosis of cognitive impairments or in assessing the risk of their occurrence. The aim is to determine the sensitivity and specificity of audiological methods for the diagnosis of postoperative cognitive dysfunction (POCD). Material and methods . The study involved 40 patients (17 women and 23 men) aged 22 to 77 years. All patients underwent planned abdominal surgery or reconstructive operations on the vessels of the lower extremities using different types of anesthesia. Before and after the operation, all patients underwent neuropsychological assessment of their cognitive status and audiological examination (otoscopy, tonal threshold audiometry, speech tests). Results. The hearing thresholds in a tonal audiometry in all young patients were within normal limits. Peripheral hearing loss was detected in 11,8% of middle-aged patients and 81,8% of the elderly. Initial cognitive impairment based on the results of the MoCA test was also most often observed in a group of elderly patients. POCD was diagnosed in 63,6% of elderly patients, 35,3% of middle-aged and 8,3% of young patients. The results of preoperative speech testing revealed pronounced signs of a deficit in central processing of acoustic information in patients of all age groups. In all elderly patients, there were deviations in at least one of the speech tests, and in 63,6% ofpatients — in both tests (dichotic, RuMatrix). The high sensitivity of speech tests to the assessment of the probability of occurrence of POCD was revealed: for the dichotic test, the sensitivity was 85,7%, for the RuMatrix test 78,6%. Conclusions. Speech audiological tests are highly sensitive, which makes it appropriate to use them at the stage of preoperative diagnosis. Identify deviations from the norm in both speech tests at the preoperative stage may indicate a high probability of development of POCD.

Fronto-Temporal Coupling Dynamics During Spontaneous Activity and Auditory Processing in the Bat Carollia perspicillata.

Most mammals rely on the extraction of acoustic information from the environment in order to survive. However, the mechanisms that support sound representation in auditory neural networks involving sensory and association brain areas remain underexplored. In this study, we address the functional connectivity between an auditory region in frontal cortex (the frontal auditory field, FAF) and the auditory cortex (AC) in the bat Carollia perspicillata. The AC is a classic sensory area central for the processing of acoustic information. On the other hand, the FAF belongs to the frontal lobe, a brain region involved in the integration of sensory inputs, modulation of cognitive states, and in the coordination of behavioral outputs. The FAF-AC network was examined in terms of oscillatory coherence (local-field potentials, LFPs), and within an information theoretical framework linking FAF and AC spiking activity. We show that in the absence of acoustic stimulation, simultaneously recorded LFPs from FAF and AC are coherent in low frequencies (1–12 Hz). This “default” coupling was strongest in deep AC layers and was unaltered by acoustic stimulation. However, presenting auditory stimuli did trigger the emergence of coherent auditory-evoked gamma-band activity (>25 Hz) between the FAF and AC. In terms of spiking, our results suggest that FAF and AC engage in distinct coding strategies for representing artificial and natural sounds. Taken together, our findings shed light onto the neuronal coding strategies and functional coupling mechanisms that enable sound representation at the network level in the mammalian brain.

Spectro-temporal modulation detection and its relation to speech perception in children with auditory processing disorder

ObjectivesPoor speech perception in noise is one of the most common complaints reported for children with auditory processing disorder (APD). APD is defined as a deficit in perceptual processing of acoustic information in the auditory system in which decreased spectro-temporal resolution may also contribute. Since the recognition of spoken message in the context of other sounds, is based on the processing of auditory spectro-temporal modulations, the assessment of spectro-temporal modulations sensitivity can evaluate the listener's ability to retrieve and integrate speech segments covered by noise. Therefore, the purpose of this study was to examine spectro-temporal modulation (STM) detection and its relation to speech perception in children with APD and to compare the results with aged-matched normally developed children. Methods35 children with APD and 32 normal hearing children (8–12 years old) were enrolled. In order to examine STM detection performance, six different STM stimulus conditions were employed using three different temporal modulation rates (4, 12 and 32 Hz) and two different spectral modulation densities (0.5 and 2.0 cycles/octave). Initially, the STM detection thresholds at these six STM stimulus conditions were measured in both groups and the results were compared. Thereafter, the relation between STM detection thresholds and speech perception tests, including consonant-vowel in noise and word in noise tests were assessed. ResultsThe STM sensitivity was poorer than normal for APD children at all STM stimulus conditions. Children with APD displayed significantly poorer STM detection thresholds than those of normally developed children (p < 0.05). Significant correlations were found between STM detection thresholds and speech perception in noise in both groups (p < 0.05). ConclusionThe results suggest that the altered encoding of spectro-temporal acoustic cues in the auditory nervous system may be one of the underlying factors of reduced STM detection performance in children with APD. The present study may suggest that poor ability to extract STM cues in children with APD, can be an underlying factor for their listening problems in noise and poor speech perception in challenging situations.

Psychoacoustic methods in diagnosis of central auditory processing disorders in prematurely born children

The presence of numerous perinatal risk factors and comorbid pathology in prematurely born children, even in the absence of peripheral auditory deficit, can lead to disruptions in the processes of higher nervous sound information processing with the formation of central auditory disorders. Audiological assessment of the functional state of auditory system central parts in prematurely born children. The study involved 54 deeply premature born infants, which were divided into 3 groups depending on age (6-7, 8-9, and 10-11 years), 18 subjects in each group, and 70 healthy, term-born children of the corresponding age. In addition to the traditional audiological examination, all children underwent an assessment of functional state of the central parts of auditory system through a pause detection test (Random Gap Detection Test, RGDT); the perception of fast rhythmic sequences of stimuli, monaural low excess speech testing, binaural interaction test in alternating binaural speech format (ABS ), dichotic presentation of pairs of single digits, single digits and monosyllables, two-digit numerals, Russian matrix phrasal test in noise (RUMatrix) were studied. Prematurely born infants of all age groups were significantly worse compared to control group (p<0.01) while having RGDT, a test for assessing the perception of fast rhythmic sequences of stimuli and dichotic binaural integration tests. Monaural intelligibility of monosyllabic words in silence in children of all three groups did not differ from normal values, but it suffered from contralateral use of noise interference in children aged 6-7. According to the RUMatrix test, legibility of phrases in noise was impaired in 65% of subjects. Test results in the ABS format revealed a significant violation of speech intelligibility (p<0.01) only in children of the younger age group. In prematurely born children, there is a dysfunction of the central parts of the auditory system, which is multilevel in nature, partially leveling as children grow older. Moreover, the processes of temporary processing of acoustic information suffer to the greatest extent, not being compensated up to adolescence.

Effects of native language experience on Mandarin lexical tone processing in proficient second language learners.

Learning the acoustic and phonological information in lexical tones is significant for learners of tonal languages. Although there is a wealth of knowledge from studies of second language (L2) tone learning, it remains unclear how L2 learners process acoustic versus phonological information differently depending on whether their first language (L1) is a tonal language. In the present study, we first examined proficient L2 learners of Mandarin with tonal and nontonal L1 in a behavioral experiment (identifying a Mandarin tonal continuum) to construct tonal contrasts that could differentiate the phonological from the acoustic information in Mandarin lexical tones for the L2 learners. We then conducted an ERP experiment to investigate these learners' automatic processing of acoustic and phonological information in Mandarin lexical tones by mismatch negativity (MMN). Although both groups of L2 learners showed similar behavioral identification features for the Mandarin tonal continuum as native speakers, L2 learners with nontonal L1, as compared with both native speakers and L2 learners with tonal L1, showed longer reaction time to the tokens of the Mandarin tonal continuum. More importantly, the MMN data further revealed distinct roles of acoustic and phonological information on the automatic processing of L2 lexical tones between the two groups of L2 learners. Taken together, the results indicate that the processing of acoustic and phonological information in L2 lexical tones may be modulated by L1 experience with a tonal language. The theoretical implications of the current study are discussed in light of models of L2 speech learning.

Processing of Acoustic Information in Lexical Tone Production and Perception by Pediatric Cochlear Implant Recipients.

Purpose: This study examined the utilization of multiple types of acoustic information in lexical tone production and perception by pediatric cochlear implant (CI) recipients who are native speakers of Mandarin Chinese.Methods: Lexical tones were recorded from CI recipients and their peers with normal hearing (NH). Each participant was asked to produce a disyllabic word, yan jing, with which the first syllable was pronounced as Tone 3 (a low dipping tone) while the second syllable was pronounced as Tone 1 (a high level tone, meaning “eyes”) or as Tone 4 (a high falling tone, meaning “eyeglasses”). In addition, a parametric manipulation in fundamental frequency (F0) and duration of Tones 1 and 4 used in a lexical tone recognition task in Peng et al. (2017) was adopted to evaluate the perceptual reliance on each dimension.Results: Mixed-effect analyses of duration, intensity, and F0 cues revealed that NH children focused exclusively on marking distinct F0 contours, while CI participants shortened Tone 4 or prolonged Tone 1 to enhance their contrast. In line with these production strategies, NH children relied primarily on F0 cues to identify the two tones, whereas CI children showed greater reliance on duration cues. Moreover, CI participants who placed greater perceptual weight on duration cues also tended to exhibit smaller changes in their F0 production.Conclusion: Pediatric CI recipients appear to contrast the secondary acoustic dimension (duration) in addition to F0 contours for both lexical tone production and perception. These findings suggest that perception and production strategies of lexical tones are well coupled in this pediatric CI population.