Auditory Neuroscience

Auditory models have been developed for decades to simulate characteristics of the human auditory system, but it is often unknown how well auditory models compare to each other or perform in tasks they were not primarily designed for. This study systematically analyzes predictions of seven publicly-available cochlear filter models in response to a fixed set of stimuli to assess their capabilities of reproducing key aspects of human cochlear mechanics. The following features were assessed at frequencies of 0.5, 1, 2, 4, and 8 kHz: cochlear excitation patterns, nonlinear response growth, frequency selectivity, group delays, signal-in-noise processing, and amplitude modulation representation. For each task, the simulations were compared to available physiological data recorded in guinea pigs and gerbils as well as to human psychoacoustics data. The presented results provide application-oriented users with comprehensive information on the advantages, limitations and computation costs of these seven mainstream cochlear filter models.

BACKGROUND:
In spite of its indusrial usefulness and varied daily uses, lead (Pb) pollution is a widespread ecological problem that faces the humans in the 21th century. Pb was found to produces a wide range of toxic effects including neurotoxicity especially to the developing and young offspring. Recently, the utilization of herbal plants has received a significant attention where there has been rising awareness in their therapeutic use; among these is the garlic.
AIM OF THE WORK:
In light of the above, the current study is designed experimentally in female pregnant rats in order to investigate the beneficial role of garlic extract in the protection from the maternal and fetal cerebellar damage that produced by administration of different doses of Pb during pregnancy.
MATERIALS AND METHODS:
Positively pregnant female rats were divided into five groups; one control group, two Pb-treated groups (exposed to 160 and 320 mg/kg b.wt. of Pb, respectively) and two groups treated with both Pb and garlic (exposed to Pb as previous groups together with 250 mg/ kg b.wt. /day of garlic extract). Treatments started from day 1 till day 20 of pregnancy, where the mother rats of different experimental groups were sacrified to obtain the fetuses. Pb level in the maternal nd fetal blood and cerebellum was estimated by spectrophotometry. Specimens of the cerebellum of different mother and fetal groups were processed to histological and immunohistochemical staining for microscopic examination.
RESULTS:
The results showed that administration of Pb to pregnant rats resulted in a dose-dependent toxicity for both mothers and fetuses in the form of decrease of maternal weight gain, placental and fetal weights, brain weight and diminished fetal growth parameters, which were prominent in rat's group treated with larger dose of Pb. In Pb-treated rats, Pb level in blood and cerebellum was high when compared to the control. The histopathological examination of the cerebellum of treated dams and fetuses showed marked alterations mainly in the form of Purkinje cell degeneration and lack of deveopmet of fetal cerebellum. Co-treatment of garlic extract along with Pb resulted in a significant decrease in Pb levels as compared with those treated with Pb alone with improvement of the histopathological changes.
CONCLUSIONS:
This study was useful in evaluating the hazardous effects of uncontrolled use of Pb in general and in assessing the developmental and neurotoxicity of fetuses due to exposure during pregnancy in particular. Co-administration of garlic has beneficial effects in amelioration of Pb-induced neurotoxicity and reversing the histopathological changes of the cerebellum of mother rats and fetuses.
KEYWORDS:
garlic; glial fibrillary acidic protein; lead; purkinje cells

ABSTRACT
Objective: The aim of this study was to develop a screening questionnaire for auditory processing disorder
(APD).
Design: Fifty-questions were created to enable parent/teacher proxies to rate students listening skills interms of auditory processing, attention and language factors.
Study sample: Parents rated their child’s frequency of competent performance (most times, often, some-times or rarely) on 50 questions. Scores were calculated for three scales: auditory processing,
attention and language. Data was collected from 198 normal controls, 20 students with auditoryprocessing dis-order, 40 students with attention deficit hyperactivity disorder and 10 students with a
learning disability. Subjects were split into a younger group (7–10 y) and an older group (11–17 y).
Results: Factor analysis revealed substantial internal validity. Analysis of external validity using a regressionmodel revealed significant differences between normal and clinical groups for all scales (p < 0.001)
and also significantly separated the three clinical groups. A group differential analysis of scale score
results clearly demonstrated inter-group differences at 89% (on average) sensitivity and specificity levels.
Conclusion: The auditory processing domains questionnaire appears to be an effective screening questionnaire for APD with scale score patterns likely to be helpful in making appropriate clinical referrals.

Binaural beats have been hypothesized as a potential tool for creating cognitive
stimulation for over a hundred years (Peterson, J. 1916). When two slightly different tones are
played simultaneously in each our brains synchronize the two into one tone. The resulting tone
can stimulate certain brain areas and either increase or decrease their functioning. The objective
of this research was to determine the overall efficacy, lasting effect, and dosage needed of
binaural beats stimulation for the purposes of increasing focus and working memory. A
systematic review was conducted using the PRISMA method, where 23 peer-reviewed studies
were examined relating to binaural beats stimulation specifically for the purposes of assessing
attention and memory networks. Forty Hertz binaural beats are the most effective for increasing
focus and attention, however the methodology applied is significantly connected with results,
where the minimum dosage needs to be at least nine minutes. Further, longer exposure correlates
with an increased effect. Carrier tones should be played at a frequency that is comfortable and
perceivable (90 and 440 Hz). Timing of binaural beats stimulation should be applied either
before or before and during any proposed cognitive task. Playing binaural beats stimulation
during the cognitive task alone may index their effect. Because this is a novel topic, deductive
reasoning was applied to render results. Future studies should examine the topic of dosage and
lasting effect concerning binaural beats stimulation to access the full breadth of their
effectiveness on attention and working memory networks.

Auditory and visual imagery were studied in a sample of 128 participants, including 34 self-reported aphantasics. Auditory imagery (Bucknell Auditory Imagery Scale-Vividness, BAIS-V) and visual imagery (Vividness of Visual Imagery Questionnaire-Modified, VVIQ-M) were strongly associated, Spearman's rho = 0.83: Most self-reported aphantasics also reported weak or entirely absent auditory imagery; and participants lacking auditory imagery tended to be aphantasic. Similarly, vivid visual imagery tended to co-occur with vivid auditory imagery. Nevertheless, the aphantasic group included one individual with typical auditory imagery; and the group lacking auditory imagery (N = 29) included one individual with typical visual imagery. Hence, weak visual and auditory imagery can dissociate, albeit with low apparent incidence. Auditory representations and auditory imagery are thought to play a key role in a wide range of psychological domains, including working memory and memory rehearsal, prospective cognition, thinking, reading, planning, problem-solving, self-regulation, and music. Therefore, self-reports describing an absence of auditory imagery raise a host of important questions concerning the role of phenomenal auditory imagery in these domains. Because there is currently no English word denoting an absence of auditory imagery, we propose a new term, anauralia, for referring to this, and offer suggestions for further research.

According to sensorimotor theory perceiving is a bodily skill involving exercise of an implicit know-how of the systematic ways that sensations change as a result of potential movements, that is, of sensorimotor contingencies. The theory has been most successfully applied to vision and touch, while perceptual modalities that rely less on overt exploration of the environment have not received as much attention. In addition, most research has focused on philosophically grounding the theory and on psychologically elucidating sensorimotor laws, but the theory's ramifications for neuroscience still remain underexamined. Here we sketch the beginnings of a research program that could address these two outstanding challenges in terms of auditory perception. We review the neuroscience literature on passive listening, which is defined as listening without overt bodily movement, and conclude that sensorimotor theory provides a unique perspective on the consistent finding of motor system activation. In contrast to competing theories, this activation is predicted to be involved not only in the perception of speech-and action-related sounds, but in auditory perception in general. More specifically, we propose that the auditory processing associated with supplementary motor areas forms part of the neural basis of the exercise of sensorimotor know-how: these areas' recognized role in (1) facilitating spontaneous motor responses to sound and (2) supporting flexible engagement of sensorimotor processes to guide auditory experience and enable auditory imagery, can be understood in terms of two key characteristics of sensorimotor interaction, its (1) "alerting capacity" (or "grabbiness") and (2) "corporality" (or "bodiliness"), respectively. We also highlight that there is more to the inside of the body than the brain: there is an opportunity to develop sensorimotor theory into new directions in terms of the still poorly understood active processes of the peripheral auditory system.

This dissertation argues that whilst our inherent auditory cognition allows us to hear and differentiate between sounds, it is ultimately our individual human experience and learned behaviour that shapes our perception of sound as music. The mechanism of hearing itself, referred to as auditory cognition, allows us to hear sound as music and is an important and expanding area of research within the field of experimental psychology and psychoacoustics. But in order to fully appreciate certain aspects of our own musical behaviour, such as our different and very often unique, perception of sound as music, we need to gain a better understanding of the psychology of hearing, and the complex field of psychoacoustics.

Comparisons of musicians and non-musicians have revealed enhanced cognitive and sensory processing in musicians, with longitudinal studies suggesting these enhancements may be due in part to experience-based plasticity. Here, we investigate the impact of primary instrument on the musician signature of expertise by assessing three groups of young adults: percussionists, vocalists, and non-musician controls. We hypothesize that primary instrument engenders selective enhancements reflecting the most salient acoustic features to that instrument, whereas cognitive functions are enhanced regardless of instrument. Consistent with our hypotheses, percussionists show more precise encoding of the fast-changing acoustic features of speech than non-musicians, whereas vocalists have better frequency discrimination and show stronger encoding of speech harmonics than non-musicians. There were no strong advantages to specialization in sight-reading vs. improvisation. These effects represent subtle nuances to the signature since the musician groups do not differ from each other in these measures. Interestingly, percus-sionists outperform both non-musicians and vocalists in inhibitory control. Follow-up analyses reveal that within the vocalists and non-musicians, better proficiency on an instrument other than voice is correlated with better inhibitory control. Taken together, these outcomes suggest the more extensive engagement of motor systems during instrumental practice may be an important factor for enhancements in inhibitory control, consistent with evidence for overlapping neural circuitry involved in both motor and cog-nitive control. These findings contribute to the ongoing refinement of the musician signature of expertise and may help to inform the use of music in training and intervention to strengthen cognitive function.

Natural auditory scenes consist of a rich variety of temporally overlapping sounds that originate from multiple sources and locations and are characterized by distinct acoustic features. It is an important biological task to analyze such complex scenes and extract sounds of interest. The thesis addresses this question, also known as the “cocktail party problem” by developing an approach based on analysis of a novel stochastic signal contrary to deterministic narrowband signals used in previous work. This low-level signal, known as the Stochastic Figure-Ground (SFG) stimulus captures the spectrotemporal complexity of natural sound scenes and enables parametric control of stimulus features. In a series of experiments based on this stimulus, I have investigated specific behavioural and neural correlates of human auditory figure-ground segregation.

This thesis is presented in seven sections. Chapter 1 reviews key aspects of auditory processing and existing models of auditory segregation. Chapter 2 presents the principles of the techniques used including psychophysics, modeling, functional Magnetic Resonance Imaging (fMRI) and Magnetoencephalography (MEG). Experimental work is presented in the following chapters and covers figure-ground segregation behaviour (Chapter 3), modeling of the SFG stimulus based on a temporal coherence model of auditory perceptual organization (Chapter 4), analysis of brain activity related to detection of salient targets in the SFG stimulus using fMRI (Chapter 5), and MEG respectively (Chapter 6). Finally, Chapter 7 concludes with a general discussion of the results and future directions for research.

Overall, this body of work emphasizes the use of stochastic signals for auditory scene analysis and demonstrates an automatic, highly robust segregation mechanism in the auditory system that is sensitive to temporal correlations across frequency channels.

Although the Ancients placed great emphasis on delivery, modern rhetorical scholars often overlook the oral dimensions of speech. Speech is powerful because of its ability to elicit a somatic response. Scholars in other disciplines are examining how speech affects the body, but contemporary rhetorical scholarship often overlooks their findings. This essay reviews scholarship both inside and outside of communication studies that demonstrates the interplay between rhetoric and orality, paying particular attention to how scientific scholarship can inform our conception of ethos and pathos. By drawing together scientific and rhetorical scholarship, scholars in all disciplines can gain a greater understanding of how speech affects the mind, body, and soul.

Purpose: The aim of this study was to compare release from masking (RM) between Mandarin-speaking and English-speaking listeners with normal hearing for competing speech when target-masker sex cues, spatial cues, or both were available. Method: Speech recognition thresholds (SRTs) for competing speech were measured in 21 Mandarin-speaking and 15 English-speaking adults with normal hearing using a modified coordinate response measure task. SRTs were measured for target sentences produced by a male talker in the presence of two masker talkers (different male talkers or female talkers). The target sentence was always presented directly in front of the listener, and the maskers were either colocated with the target or were spatially separated from the target (+90°, −90°). Stimuli were presented via headphones and were virtually spatialized using head-related transfer functions. Three masker conditions were used to measure RM relative to the baseline condition: (a) talker sex cues, (b) spatial cues, or (c) combined talker sex and spatial cues. Results: The results showed large amounts of RM according to talker sex and/or spatial cues. There was no significant difference in SRTs between Chinese and English listeners for the baseline condition, where no talker sex or spatial cues were available. Furthermore, there was no significant difference in RM between Chinese and English listeners when spatial cues were available. However, RM was significantly larger for Chinese listeners when talker sex cues or combined talker sex and spatial cues were available. Conclusion: Listeners who speak a tonal language such as Mandarin Chinese may be able to take greater advantage of talker sex cues than listeners who do not speak a tonal language.

Terhune, D. B., Luke, D. P., Kaelen, M., Bolstridge, M., Feilding, A., Nutt, D., Carhart-Harris, R., Ward, J. (2016). A placebo-controlled investigation of synaesthesia-like experiences under LSD. Neuropsychologia, 88, 28-34. http://dx.doi.org/10.1016/j.neuropsychologia.2016.04.005

The young nervous system is primed for sensory learning, facilitating the acquisition of language and communication skills. Social and linguistic impoverishment can limit these learning opportunities, eventually leading to language-related challenges such as poor reading. Music training offers a promising auditory learning strategy by directing attention to meaningful acoustic elements of the soundscape. In light of evidence that music training improves auditory skills and their neural substrates, there are increasing efforts to enact community-based programs to provide music instruction to at-risk children. Harmony Project is a community foundation that has provided free music instruction to over 1000 children from Los Angeles gang-reduction zones over the past decade. We conducted an independent evaluation of biological effects of participating in Harmony Project by following a cohort of children for 1 year. Here we focus on a comparison between students who actively engaged with ...

Time is an important dimension of brain function, but little is still known about the underlying cognitive principles and neurobiological mechanisms. The field of timing and time perception has witnessed rapid growth and multidisciplinary interest in the recent years with the advent of modern neuroimaging, neurophysiological and optogenetic tools. In this article, I review the literature from the last ten years (2005-2015) using a data mining approach and highlight the most significant empirical as well as review articles based on the number of citations (a minimum of 100 citations). Such analysis provides a unique perspective on the current state-of-the-art in the field and highlights subtopics in the field that have received considerable attention, and those that have not. The aim of the article is to present an objective summary of the current progress in the field of timing and time perception and provide a valuable and accessible resource summarizing the most cited articles for new as well current investigators in the field.

A didactic explanation for fellow time-travelers on how to deal with the current pandemic apathy by 'modern' physicists over the facticity of time-travel and obvious evidence which proves the existence of the phenomenon.  This is my effort to help other time-travelers understand how to deal with the unruly, sometimes less-than-human, concepts of physicists who clearly need to be 'collared' and reined-in, trained and schooled.

Auditory and visual imagery were studied in a sample of 128 participants, including 34 self-reported aphantasics. Auditory imagery (Bucknell Auditory Imagery Scale-Vividness, BAIS-V) and visual imagery (Vividness of Visual Imagery Questionnaire-Modified, VVIQ-M) were strongly associated, Spearman&#39;s rho = 0.83: Most self-reported aphantasics also reported weak or entirely absent auditory imagery; and participants lacking auditory imagery tended to be aphantasic. Similarly, vivid visual imagery tended to co-occur with vivid auditory imagery. Nevertheless, the aphantasic group included one individual with typical auditory imagery; and the group lacking auditory imagery (N = 29) included one individual with typical visual imagery. Hence, weak visual and auditory imagery can dissociate, albeit with low apparent incidence. Auditory representations and auditory imagery are thought to play a key role in a wide range of psychological domains, including working memory and memory rehearsal...

The noise-induced and age-related loss of synaptic connections between auditory-nerve fibers and cochlear hair cells is well-established from histopathology in several mammalian species; however, its prevalence in humans, as inferred from electrophysiological measures, remains controversial. Here we look for cochlear neuropathy in a temporal-bone study of ''normal-aging" humans, using autopsy material from 20 subjects aged 0-89 yrs, with no history of otologic disease. Cochleas were immunostained to allow accurate quantification of surviving hair cells in the organ Corti and peripheral axons of auditory-nerve fibers. Mean loss of outer hair cells was 30-40% throughout the audiometric frequency range (0.25-8.0 kHz) in subjects over 60 yrs, with even greater losses at both apical (low-frequency) and basal (high-frequency) ends. In contrast, mean inner hair cell loss across audiometric frequencies was rarely >15%, at any age. Neural loss greatly exceeded inner hair cell loss, with 7/11 subjects over 60 yrs showing >60% loss of peripheral axons re the youngest subjects, and with the age-related slope of axonal loss outstripping the age-related loss of inner hair cells by almost 3:1. The results suggest that a large number of auditory neurons in the aging ear are disconnected from their hair cell targets. This primary neural degeneration would not affect the audiogram, but likely contributes to age-related hearing impairment, especially in noisy environments. Thus, therapies designed to regrow peripheral axons could provide clinically meaningful improvement in the aged ear. Ó 2018 The Author(s). Published by Elsevier Ltd on behalf of IBRO. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

In this article the problem of perception is highlighted from a philosophical, physiological and psychological point of view. The essay (second update) is followed by a list of publications, journals and websites about perception. The author would be delighted to receive comments. He can be contacted at j[underscore]kuijper[at]online[dot]nl.

Despite the outstanding auditory capabilities of dolphins, there is only limited information available on the cytology of the auditory brain stem nuclei in these animals. Here, we investigated the cochlear nuclei (CN) of five brains of common dolphins (Delphinus delphis) and La Plata dolphins (Pontoporia blainvillei) using cell and fiber stain microslide series representing the three main anatomical planes. In general, the CN in dolphins comprise the same set of subnuclei as in other mammals. However, the volume ratio of the dorsal coch-lear nucleus (DCN) in relation to the ventral cochlear nucleus (VCN) of dolphins represents a minimum among the mammals examined so far. Because, for example, in cats the DCN is necessary for reflexive orientation of the head and pinnae towards a sound source, the massive restrictions in head movability in dolphins and the absence of outer ears may be correlated with the reduction of the DCN. Moreover, the same set of main neuron types were found in the dolphin CN as in other mammals , including octopus and multipolar cells. Because the latter two types of neurons are thought to be involved in the recognition of complex sounds, including speech, we suggest that, in dolphins, they may be involved in the processing of their communication signals. Comparison of the toothed whale species studied here revealed that large spherical cells were present in the La Plata dolphin but absent in the common dolphin. These neurons are known to be engaged in the processing of low-frequency sounds in terrestrial mammals. Accordingly, in the common dolphin, the absence of large spherical cells seems to be correlated with a shift of its auditory spectrum into the high-frequency range above 20 kHz. The existence of large spherical cells in the VCN of the La Plata dolphin, however, is enigmatic as this species uses frequencies around 130 kHz.

The organ of Corti, consisting of a layer of hair cells, that is long and thin, receives the vibrations transmitted in the fluid of the cochlea and transmits them, through their lower extremities which are in contact with the nerve endings (neurons) of the acoustic nerve , to the membrane, which has the important characteristic of tonotopicity ( Tonotopia (from the Greek tone- and topos = place of sounds) is a spatial distribution of where sounds are perceived, transmitted or received ...

Participation is the engine of cultural production. In the case of literature, the privileged modality that enables participation is auditory perception. In order to articulate a theory of literary cultural production based on auditory perception, participation needs to be analyzed in the context of Platonic methexis, understood as an embodied experience facilitated by brain mechanisms of sensory processing and cognition, which manifest in specific ways in written texts. The Siete Partidas, the first complete and systematic legal code of the Western World, provides the perfect case study to test a theory of literary cultural production based on methexis via auditory perception, because it is one of the first complete texts written in Castilian, making it ideal to illustrate the ways in which methexis affects the process of elaboration of a cultural product in a language that does not have a precedent in the form of an extensive body of texts, nor has it had time to develop a normalized system of grammar and rhetoric.

Hearing aids are able to restore some hearing abilities for people with auditory impairments, but background noise remains a significant problem. Unfortunately, we know very little about how speech is encoded in the auditory system, particularly in impaired systems with prosthetic amplifiers. There is growing evidence that relative timing in the neural signals (known as spatiotemporal coding) is important for speech perception, but there is little research that relates spatiotemporal coding and hearing aid amplification.
This research used a combination of computational modeling and neurophysiological experiments to characterize how hearing aids affect vowel coding in noise at the level of the auditory nerve. The results indicate that sensorineural hearing impairment degrades the temporal cues transmitted from the ear to the brain. Two hearing aid strategies (linear gain and wide dynamic-range compression) were used to amplify the acoustic signal. Although appropriate gain was shown to improve temporal coding for individual auditory nerve fibers, neither strategy improved spatiotemporal cues.
Previous work has attempted to correct the relative timing by adding frequency-dependent delays to the acoustic signal (e.g., within a hearing aid). We show that, although this strategy can affect the timing of individual auditory nerve responses, there is a fundamental limitation in the ability of this approach to improve the relative across-fiber timing (spatiotemporal coding) as intended.
We have shown that existing hearing aid technologies do not improve some of the neural cues that we think are important for perception, but it is important to understand these limitations. Our hope is that this knowledge can be used to develop new technologies to improve auditory perception in difficult acoustic environments.

Building on the notational principles of C. S. Peirce’s graphical logic, Pietarinen has tried to develop a propositional logic unfolding in the medium of sound. Apart from its intrinsic interest, this project serves as a concrete test of logic’s range. However, I argue that Pietarinen’s inaugural proposal, while promising, has an important shortcoming, since it cannot portray double-negation without thereby portraying a contradiction.

According to sensorimotor theory perceiving is a bodily skill involving exercise of an implicit know-how of the systematic ways that sensations change as a result of potential movements, that is, of sensorimotor contingencies. The theory has been most successfully applied to vision and touch, while perceptual modalities that rely less on overt exploration of the environment have not received as much attention. In addition, most research has focused on philosophically grounding the theory and on psychologically elucidating sensorimotor laws, but the theory’s ramifications for neuroscience still remain underexamined. Here we sketch the beginnings of a research program that could address these two outstanding challenges in terms of auditory perception. We review the neuroscience literature on passive listening, which is defined as listening without overt bodily movement, and conclude that sensorimotor theory provides a unique perspective on the consistent finding of motor system activation. In contrast to competing theories, this activation is predicted to be involved not only in the perception of speech- and action-related sounds, but in auditory perception in general. More specifically, we propose that the auditory processing associated with supplementary motor areas forms part of the neural basis of the exercise of sensorimotor know-how: these areas’ recognized role in (1) facilitating spontaneous motor responses to sound and (2) supporting flexible engagement of sensorimotor processes to guide auditory experience and enable auditory imagery, can be understood in terms of two key characteristics of sensorimotor interaction, its (1) “alerting capacity” (or “grabbiness”) and (2) “corporality” (or “bodiliness”), respectively. We also highlight that there is more to the inside of the body than the brain: there is an opportunity to develop sensorimotor theory into new directions in terms of the still poorly understood active processes of the peripheral auditory system.