Representation Of Sounds Research Articles

Peripheral deficits and phase-locking declines in aging adults

Age-related difficulties in speech understanding may arise from a decrease in the neural representation of speech sounds. A loss of outer hair cells or decrease in auditory nerve fibers may lead to a loss of temporal precision that can affect speech clarity. This study's purpose was to evaluate the peripheral contributors to phase-locking strength, a measure of temporal precision, in recordings to a sustained vowel in 30 younger and 30 older listeners with normal to near normal audiometric thresholds. Thresholds were obtained for pure tones and distortion-product otoacoustic emissions (DPOAEs). Auditory brainstem responses (ABRs) were recorded in quiet and in three levels of continuous white noise (+30, +20, and +10 dB SNR). Absolute amplitudes and latencies of Wave I in quiet and of Wave V across presentation conditions, in addition to the slope of Wave V amplitude and latency changes in noise, were calculated from these recordings. Frequency-following responses (FFRs) were recorded to synthesized /ba/ syllables of two durations, 170 and 260 ms, to determine whether age-related phase-locking deficits are more pronounced for stimuli that are sustained for longer durations. Phase locking was calculated for the early and late regions of the steady-state vowel for both syllables. Group differences were found for nearly every measure except for the slopes of Wave V latency and amplitude changes in noise. We found that outer hair cell function (DPOAEs) contributed to the variance in phase locking. However, the ABR and FFR differences were present after covarying for DPOAEs, suggesting the existence of temporal processing deficits in older listeners that are somewhat independent of outer hair cell function.

The mental representation of sounds in speech sound disorders

The objective of this study is to investigate facets of the human phonological system in an attempt to elucidate the special nature of mental representations and operations underlying some of the errors in speech sound disorders (SSDs). After examining different theories on the mental representations of sounds and their organization in SSDs, we arrive at the conclusion that the existing elucidations on the phonological representations do not suffice to explain some distinctive facets of SSDs. Here, we endorse a hypothesis in favor of representationalism but offer an alternative conceptualization of the phonological representations (PR). We argue that the PR is to be understood in terms of a phonological base that holds information about a segment’s acoustic structure, and which interacts with other levels in the speech sound system in the mind so as to produce a certain sound. We also propose that the PR is connected to an interface module which mediates interactions between the PR and the articulatory system (AS) responsible for the physical manifestation of speech sounds in real time by way of the coordination of activities of speech organs in the vocal tract. We specifically consider different stages of operations within the interface, a specialized system within the cognitive system, which can explain patterns in the SSD data that have so far remained elusive. Positioned between the PR and the AS, the interface module is the heart of the current study. The presence of an interface module is necessitated by the fact that not all errors of SSDs are explainable in terms of structural, motor or even the symbolic misrepresentations at the level of PR. The interface acts as a mediating system mapping sound representations onto articulatory instructions for the actual production of sounds. The interface module can receive, process, and share the phonological inputs with other levels within the speech sound system. We believe an interface module such as ours holds the key to explaining at least certain speech disarticulations in SSDs.

Scaling of Eliassen‐Palm flux vectors

AbstractEliassen‐Palm flux is one of the main diagnostics tools for wave propagation and wave‐mean flow interaction in atmospheric dynamics and in particular stratosphere‐troposphere coupling. Even though the theory has been derived in the 1960s, there is still no consensus about how to display the flux vectors in a plot. This is particularly true where both the troposphere and stratosphere are of importance. Some of the traditional methods are to scale the arrows by either pressure, the exponential of height, the square root of pressure, or even by an arbitrary factor. But the arguments for any of those methods are subjective, and they result in both different amplitudes and direction. Here, we propose an objective way of scaling EP flux vectors, in either linear or logarithmic pressure or height coordinates, which allows for a physically sound representation throughout the entire atmosphere.

Vowel Sound Synthesis from Electroencephalography during Listening and Recalling

Recent advances in brain imaging technology have furthered our knowledge of the neural basis of auditory and speech processing, often via contributions from invasive brain signal recording and stimulation studies conducted intraoperatively. Herein, an approach for synthesizing vowel sounds straightforwardly from scalp‐recorded electroencephalography (EEG), a noninvasive neurophysiological recording method is demonstrated. Given cortical current signals derived from the EEG acquired while human participants listen to and recall (i.e., imagined) two vowels, /a/ and /i/, sound parameters are estimated by a convolutional neural network (CNN). The speech synthesized from the estimated parameters is sufficiently natural to achieve recognition rates >85% during a subsequent sound discrimination task. Notably, the CNN identifies the involvement of the brain areas mediating the “what” auditory stream, namely the superior, middle temporal, and Heschl's gyri, demonstrating the efficacy of the computational method in extracting auditory‐related information from neuroelectrical activity. Differences in cortical sound representation between listening versus recalling are further revealed, such that the fusiform, calcarine, and anterior cingulate gyri contributes during listening, whereas the inferior occipital gyrus is engaged during recollection. The proposed approach can expand the scope of EEG in decoding auditory perception that requires high spatial and temporal resolution.

A song for Rob DeChaine: articulations of music and film in cinematic border representations

ABSTRACT This essay examines the groundbreaking film Amores Perros by the acclaimed director Alejandro González Iñárritu through the auteur's innovative deployment of popular music. By first articulating border rhetorics to popular music (both scholarly concerns of the late D. Robert DeChaine), I argue that sound representations by Iñárritu are strategically thought-provoking and culturally significant examples of U.S.-Mexican intercultural discourse. Also debunking mainstream sonic representations of “Mexicans” and/or “Mexican-ness” as tired “sonic stereotypes,” this research demonstrates how Iñárritu's film serves as a powerful tool for cinematically constructing “Mexicans” (and by logical extension, non-fictional U.S. Latino/a/xs) in more updated and potentially realistic ways.

Sounds, Violence, and Power Structures in Among the Lost by Emiliano Monge

This article analyses the auditive dimension in Emiliano Monge’s Among the Lost (2018). I argue that the sounds are connected to different forms of violence, and that their use in the novel destabilizes the rigidity of power relations between victims and perpetrators. The representation of sounds and silence concretizes the violence towards the victims, and reveals the transient nature of categories and positions within the structure of violence and power. The difference in power is symbolized by the difference in speech volume and access to environmental sounds between criminals and migrants, an allusion to the systemic violence of Monge’s border zone. Volume and intensity also refer to concrete subjective violence towards the kidnapped migrants, who are both physically and mentally tortured. The sounds and their connotations illustrate that the violent superstructure is independent of the individuals committing crimes, because they turn out to be disposable pawns, parts of a criminal system that transcends the individual.

Posthumani 'preobražaj' u/na mreži Ana Gnjatović: Arahnin san za klavir i elektroniku

The aim of this paper is to analyse Ana Gnjatović's work, Arachne's Dream, written for piano and live electronics. The work premiered in 2019 on the initiative of Nataša Penezić, a pianist to whom this work has been dedicated. Based on the idea of the sound realization of a spider web phenomenon (within an electronic medium), I will try to analyse the development path and the creation process this piece undergoes, by taking into account the extra-musical impulses as a source of inspiration. Apart from the web motif itself, taken as the basic motif which is further developed throughout the piece, the author's inspiration also stems from other models (which remain in close connection with the web phenomenon), from the ancient Greek myth of a weaver called Arachne, and Kafka's work "The Metamorphosis", to Roland Barthes' "The Pleasure of the Text". All of these 'threads' create a foundation for further music/ sound representation, based upon the interaction between an electronic part, and the pianist's actions.

Акордеонне виконавство як ігровий феномен у контексті герменевтичного підходу

The purpose of the article is to reveal the concept of performing game and its components as a holistic creative process associated with subjective (performer and his individual characteristics) and objective (instrument, musical text) factors of accordion creativity, as well as defining performance plans, in particular plans to study the accordion text. The research methodology involves a combination of hermeneutic, textual and interpretive methods, which allows to distinguish the concept of accordion text and attitude to it, which is to find new performance, values and meanings and is determined by the continuous creative activity of the performer. The scientific novelty of the study is determined by the formation of communicative-game approach to accordion performance, as a holistic process that includes subjective and objective, external and internal, technical and artistic aspects of performance. This approach deepens the understanding of accordion creativity and playing, which is the leading activity of the performer at all levels of work on the musical text – from structural to artistic. Thus, the game appears as a selfactualization of the performer’s personality, a way of expressing his intentional sphere through sound representation. Conclusions allow us to define the concept of musical performance as a holistic continuous creative process, as well as communicative-game approach as a necessary prerequisite for the formation of methodological performance guidelines and personal vision. The game, as the main activity of the performer, is organized and directed by semantic external and internal, objective and subjective factors, among which the personal intentions and authenticity (conscious architectonics of reflective consciousness) of the performer as the author of artistic interpretation are decisive. In general, the game aspect can be considered as a performance approach, covering issues of text and interpretation. Accordingly, the meaning of the game expands from a technical concept to a cognitive spiritual and semantic process.

Distinct neural ensemble response statistics are associated with recognition and discrimination of natural sound textures

The perception of sound textures, a class of natural sounds defined by statistical sound structure such as fire, wind, and rain, has been proposed to arise through the integration of time-averaged summary statistics. Where and how the auditory system might encode these summary statistics to create internal representations of these stationary sounds, however, is unknown. Here, using natural textures and synthetic variants with reduced statistics, we show that summary statistics modulate the correlations between frequency organized neuron ensembles in the awake rabbit inferior colliculus (IC). These neural ensemble correlation statistics capture high-order sound structure and allow for accurate neural decoding in a single trial recognition task with evidence accumulation times approaching 1 s. In contrast, the average activity across the neural ensemble (neural spectrum) provides a fast (tens of milliseconds) and salient signal that contributes primarily to texture discrimination. Intriguingly, perceptual studies in human listeners reveal analogous trends: the sound spectrum is integrated quickly and serves as a salient discrimination cue while high-order sound statistics are integrated slowly and contribute substantially more toward recognition. The findings suggest statistical sound cues such as the sound spectrum and correlation structure are represented by distinct response statistics in auditory midbrain ensembles, and that these neural response statistics may have dissociable roles and time scales for the recognition and discrimination of natural sounds.

Evaluating and Comparing Behavioural and Electrophysiological Estimates of Neural Health in Cochlear Implant Users

Variations in neural health along the cochlea can degrade the spectral and temporal representation of sounds conveyed by cochlear implants (CIs). We evaluated and compared one electrophysiological measure and two behavioural measures that have been proposed as estimates of neural health patterns, in order to explore the extent to which the different measures provide converging and consistent neural health estimates. All measures were obtained from the same 11 users of the Cochlear Corporation CI. The two behavioural measures were multipulse integration (MPI) and the polarity effect (PE), both measured on each of seven electrodes per subject. MPI was measured as the difference between thresholds at 80 pps and 1000 pps, and PE as the difference in thresholds between cathodic- and anodic-centred quadraphasic (QP) 80-pps pulse trains. It has been proposed that good neural health corresponds to a large MPI and to a large negative PE (lower thresholds for cathodic than anodic pulses). The electrophysiological measure was the effect of interphase gap (IPG) on the offset of the ECAP amplitude growth function (AGF), which has been correlated with spiral ganglion neuron density in guinea pigs. This ‘IPG offset’ was obtained on the same subset of electrodes used for the behavioural measures. Despite high test–retest reliability, there were no significant correlations between the neural health estimates for either within-subject comparisons across the electrode array, or between-subject comparisons of the means. A phenomenological model of a population of spiral ganglion neurons was then used to investigate physiological mechanisms that might underlie the different neural health estimates. The combined experimental and modelling results provide evidence that PE, MPI and IPG offset may reflect different characteristics of the electrode-neural interface.

Shared or Separate Representations? The Spanish Palatal Nasal in Early Spanish/English Bilinguals

The purpose of this study is to examine phonetic interactions in early Spanish/English bilinguals to see if they have established a representation for the Spanish palatal nasal /ɲ/ (e.g., /kaɲon/ cañón ‘canyon’) that is separate from the similar, yet acoustically distinct English /n+j/ sequence (e.g., /kænjn̩/ ‘canyon’). Twenty heritage speakers of Spanish completed a delayed repetition task in each language, in which a set of disyllabic nonce words were produced in a carrier phrase. English critical stimuli contained an intervocalic /n+j/ sequence (e.g., /dɛnjɑ/ ‘denya’) and Spanish critical stimuli contained intervocalic /ɲ/ (e.g., /deɲja/ ‘deña’). We measured the duration and formant contours of the following vocalic portion as acoustic indices of the /ɲ/~/n+j/ distinction. The duration data and formant contour data alike show that early bilinguals distinguish between the Spanish /ɲ/ and English /n+j/ in production, indicative of the maintenance of separate representations for these similar sounds and thus a lack of interaction between systems for bilinguals in this scenario. We discuss these discrete representations in comparison to previous evidence of shared and separate representations in this population, examining a set of variables that are potentially responsible for the attested distinction.

Interpreting the Effect of Stimulus Parameters on the Electrically Evoked Compound Action Potential and on Neural Health Estimates

Variations in the condition of the neural population along the length of the cochlea can degrade the spectral and temporal representation of sounds conveyed by CIs, thereby limiting speech perception. One measurement that has been proposed as an estimate of neural survival (the number of remaining functional neurons) or neural health (the health of those remaining neurons) is the effect of stimulation parameters, such as the interphase gap (IPG), on the amplitude growth function (AGF) of the electrically evoked compound action potential (ECAP). The extent to which such measures reflect neural factors, rather than non-neural factors (e.g. electrode orientation, electrode-modiolus distance, and impedance), depends crucially upon how the AGF data are analysed. However, there is currently no consensus in the literature for the correct method to interpret changes in the ECAP AGF due to changes in stimulation parameters. We present a simple theoretical model for the effect of IPG on ECAP AGFs, along with a re-analysis of both animal and human data that measured the IPG effect. Both the theoretical model and the re-analysis of the animal data suggest that the IPG effect on ECAP AGF slope (IPG slope effect), measured using either a linear or logarithmic input-output scale, does not successfully control for the effects of non-neural factors. Both the model and the data suggest that the appropriate method to estimate neural health is by measuring the IPG offset effect, defined as the dB offset between the linear portions of ECAP AGFs for two stimuli differing only in IPG.

Visual and Auditory Verbal Memory in Older Adults: Comparing Postlingually Deaf Cochlear Implant Users to Normal-Hearing Controls

Purpose The aim of this study was to test whether a group of older postlingually deafened cochlear implant users (OCIs) use similar verbal memory strategies to those used by older normal-hearing adults (ONHs). Verbal memory functioning was assessed in the visual and auditory modalities separately, enabling us to eliminate possible modality-based biases. Method Participants performed two separate visual and auditory verbal memory tasks. In each task, the visually or aurally presented study words were learned by vocal production (saying aloud) or by no production (reading silently or listening), followed by a free recall test. Twenty-seven older adults (> 60 years) participated (OCI = 13, ONH = 14), all of whom demonstrated intact cognitive abilities. All OCIs showed good open-set speech perception results in quiet. Results Both ONHs and OCIs showed production benefits (higher recall rates for vocalized than nonvocalized words) in the visual and auditory tasks. The ONHs showed similar production benefits in the visual and auditory tasks. The OCIs demonstrated a smaller production effect in the auditory task. Conclusions These results may indicate that different modality-specific memory strategies were used by the ONHs and the OCIs. The group differences in memory performance suggest that, even when deafness occurs after the completion of language acquisition, the reduced and distorted external auditory stimulation leads to a deterioration in the phonological representation of sounds. Possibly, this deterioration leads to a less efficient auditory long-term verbal memory.

Vagus nerve stimulation for tinnitus: A review and perspective.

Vagus nerve stimulation is a promising new tool in the treatment of chronic tinnitus. Current protocols involve pairing sounds, which exclude the tinnitus frequency, with simultaneous vagus nerve stimulation (VNS). This is based on extensive preclinical animal studies that demonstrate that pairing non-tinnitus sounds with VNS results in a tonotopic map plasticity. It is thought that by expanding the non-tinnitus sound representation, it is possible to overturn the expanded tonotopic map associated with the tinnitus frequency in these animal models. These findings have been translated into a clinical approach, where a clinically significant, but moderate improvement, in tinnitus distress and a modest benefit in tinnitus loudness perception has been shown. Yet, pairing tinnitus matched sound to VNS may produce tinnitus improvement by Pavlovian conditioning, in which the distressful tinnitus sound becomes associated with a relaxing "rest and digest" response from activation of the vagus nerve. If this hypothesis is correct, beneficial effects should be achieved with paired sounds that resemble the tinnitus sounds as much as possible. In conclusion, although the potential to use VNS to drive neural plasticity to reduce or eliminate the neural drivers of ongoing tinnitus is exciting, much work is needed to more completely understand the neural basis of tinnitus and to develop tailored therapies to address the suffering caused by this heterogeneous condition. Whether pairing of the vagus stimulation with non-tinnitus or tinnitus-matched sounds is essential is still to be determined.

Evaluation of traffic load models for fatigue verification of European road bridges

Fatigue verification of bridge structures requires information on the loads induced by heavy vehicles, which can be obtained from weigh in motion measurement (WIM) systems. The current fatigue load models applied in Europe are based on traffic load measurements in 1986. This paper evaluates the appropriateness of these models for today’s traffic by comparing their load effects with those of recent WIM databases, covering the years 2008 to 2018. A procedure is derived to determine the required size of the WIM database for a sound representation of the fatigue loads. The effects of traffic jams are evaluated and the required safety margins or partial factors are derived. As already concluded by others, it appears that the most frequently used fatigue load model is unable to represent the fatigue action effects of today’s European traffic. In addition, the paper demonstrates that the other fatigue load models are also inaccurate. A new fatigue load model is proposed that is easy in use and gives a significant improvement in accuracy compared to the existing models. The parameters in this model can easily be calibrated for other WIM databases.

Foreground stimuli and task engagement enhance neuronal adaptation to background noise in the inferior colliculus of macaques.

Auditory neuronal responses are modified by background noise. Inferior colliculus (IC) neuronal responses adapt to the most frequent sound level within an acoustic scene (adaptation to stimulus statistics), a mechanism that may preserve neuronal and behavioral thresholds for signal detection. However, it is still unclear whether the presence of foreground stimuli and/or task involvement can modify neuronal adaptation. To investigate how task engagement interacts with this mechanism, we compared the response of IC neurons to background noise, which caused adaptation to stimulus statistics, while macaque monkeys performed a masked tone detection task (task-driven condition) with responses recorded when the same background noise was presented alone (passive listening condition). In the task-dependent condition, monkeys performed a Go/No-Go task while 50-ms tones were embedded within an adaptation-inducing continuous background noise whose levels changed every 50 ms and were drawn from a probability distribution. The adaptation to noise stimulus statistics in IC neuronal responses was significantly enhanced in the task-driven condition compared with the passive listening condition, showing that foreground stimuli and/or task-engagement can modify IC neuronal responses. Additionally, the response of IC neurons to noise was significantly affected by the preceding sensory information (history effect) regardless of task involvement. These studies show that dynamic range adaptation in IC preserves behavioral and neurometric thresholds irrespective of noise type and a dependence of neuronal activity on task-related factors at subcortical levels of processing.NEW & NOTEWORTHY Auditory neuronal responses are influenced by maskers and distractors. However, it is still unclear whether the neuronal sensitivity to the masker stimulus is influenced by task-dependent factors. Our study represents one of the first attempts to investigate how task involvement influences the neural representation of background sounds in the subcortical, midbrain auditory neurons of behaving animals.

Single-neuron representation of learned complex sounds in the auditory cortex

The sensory responses of cortical neuronal populations following training have been extensively studied. However, the spike firing properties of individual cortical neurons following training remain unknown. Here, we have combined two-photon Ca2+ imaging and single-cell electrophysiology in awake behaving mice following auditory associative training. We find a sparse set (~5%) of layer 2/3 neurons in the primary auditory cortex, each of which reliably exhibits high-rate prolonged burst firing responses to the trained sound. Such bursts are largely absent in the auditory cortex of untrained mice. Strikingly, in mice trained with different multitone chords, we discover distinct subsets of neurons that exhibit bursting responses specifically to a chord but neither to any constituent tone nor to the other chord. Thus, our results demonstrate an integrated representation of learned complex sounds in a small subset of cortical neurons.

The time‐course of speech perception revealed by temporally‐sensitive neural measures

Recent advances in cognitive neuroscience have provided a detailed picture of the early time-course of speech perception. In this review, we highlight this work, placing it within the broader context of research on the neurobiology of speech processing, and discuss how these data point us toward new models of speech perception and spoken language comprehension. We focus, in particular, on temporally-sensitive measures that allow us to directly measure early perceptual processes. Overall, the data provide support for two key principles: (a) speech perception is based on gradient representations of speech sounds and (b) speech perception is interactive and receives input from higher-level linguistic context at the earliest stages of cortical processing. Implications for models of speech processing and the neurobiology of language more broadly are discussed. This article is categorized under: Psychology > Language Psychology > Perception and Psychophysics Neuroscience > Cognition.

Using high spatial resolution fMRI to understand representation in the auditory network.

Following rapid methodological advances, ultra-high field (UHF) functional and anatomical magnetic resonance imaging (MRI) has been repeatedly and successfully used for the investigation of the human auditory system in recent years. Here, we review this work and argue that UHF MRI is uniquely suited to shed light on how sounds are represented throughout the network of auditory brain regions. That is, the provided gain in spatial resolution at UHF can be used to study the functional role of the small subcortical auditory processing stages and details of cortical processing. Further, by combining high spatial resolution with the versatility of MRI contrasts, UHF MRI has the potential to localize the primary auditory cortex in individual hemispheres. This is a prerequisite to study how sound representation in higher-level auditory cortex evolves from that in early (primary) auditory cortex. Finally, the access to independent signals across auditory cortical depths, as afforded by UHF, may reveal the computations that underlie the emergence of an abstract, categorical sound representation based on low-level acoustic feature processing. Efforts on these research topics are underway. Here we discuss promises as well as challenges that come with studying these research questions using UHF MRI, and provide a future outlook.

Audacity as a tool for the creation of educational materials. An approach through the MOOC «Music for the 21st century»

This article analyses the relevance of Audacity as a creation tool of learning materials for both teachers and students, since it has multiple functions and provides numerous advantages, despite its simple use. To that purpose, thanks to the creation of an specific content analysis tool based in 8 items, an study of soundscapes created by the students of the MOOC Música para el Siglo XXI is carried out with the purpose of categorize their educative aims as well as distinguish and characterize each soundscape according with the origin of their sound source in relation with the classification proposed from Schafer (1993). Thanks to the latter analysis we know that the didactic applications are within those previously catalogued, where the use of soundscapes both to elaborate musical resources as well as to create sound representations through constructions carried out by the students make a clean sweep of almost all of the 55 analyzed compositions. The study concludes with the idea that this tool gives support to multiple areas of knowledge and that its capabilities as a multitasking tool provide a wide range of perspectives applicable within areas such as pedagogy or specific didactic fields.