Auditory Map Research Articles

Temporal Ordering and Auditory Resolution in Individuals with Sensorineural Hearing Loss.

Introduction Peripheral hearing loss, besides causing inadequate auditory input, can lead to distortions in the tonotopic auditory map and reorganization of neural networks. Therefore, the processing of temporal aspects of a sound stimulus and, consequently, the effectiveness of human communication can be negatively impacted. Objective To test the temporal ordering and auditory resolution of people with mild and moderate sensorineural hearing loss and to compare them with the those of people with normal hearing. Methods A total of 19 right-handed individuals aged 16 to 59 years with mild to moderate postlingually acquired symmetric bilateral sensorineural hearing loss participated in the study. They were submitted to frequency and duration pattern tests and a random gap detection test. Results The mean correct response rate in the frequency pattern test was of 66.3%, and, in the duration pattern test, 71.7%. The mean threshold in the random gap detection test was of 14.1 ms. A comparison with the criteria established for normal subjects without peripheral hearing loss revealed that more than half the subjects had abnormal results in the temporal ordering test, while a smaller fraction had reduced temporal resolution. Conclusions The performance of the subjects with acquired sensorineural hearing loss was poorer than that of the participants without peripheral hearing loss. Their results on the temporal ordering test were also poorer than in the temporal resolution test, demonstrating the importance of analyzing both these auditory skills in people with peripheral hearing loss.

The anatomical basis of amphibious hearing in the American alligator (Alligator mississippiensis).

The different velocities of sound (pressure waves) in air and water make auditory source localization a challenge for amphibious animals. The American alligator (Alligator mississippiensis) has an extracolumellar cartilage that abuts the deep surface of the tympanic membrane, and then expands in size beyond the caudal margin of the tympanum. This extracolumellar expansion is the insertion site for two antagonistic skeletal muscles, the tensor tympani, and the depressor tympani. These muscles function to modulate the tension in the tympanic membrane, presumably as part of the well-developed submergence reflex of Alligator. All crocodilians, including Alligator, have internally coupled ears in which paratympanic sinuses connect the contralateral middle ear cavities. The temporal performance of internally coupled ears is determined, in part, by the tension of the tympanic membrane. Switching between a "tensed" and "relaxed" tympanic membrane may allow Alligator to compensate for the increased velocity of sound underwater and, in this way, use a single auditory map for sound localization in two very different physical environments.

Vision Beyond Vision: Lessons Learned from Amblyopia

ABSTRACT Amblyopia is characterized by spatiotemporal uncertainty in the visual system. In addition to its effects on vision, amblyopia also exerts a widespread impact on other systems. Many of these changes are observed not only during amblyopic eye viewing but also during fellow eye and binocular viewing. They generally correlate with the severity of visual acuity and stereo acuity loss. The affected systems include: (1) oculomotor control manifested as abnormal fixation, saccades, smooth pursuit, and saccadic adaptation; (2) motor control with altered programming, execution, and temporal dynamics of eye-hand coordination, and decreased ability of the sensorimotor system to adapt to changes in the visual environment; (3) balance control with decreased postural stability; (4) multisensory integration characterized by reduced McGurk effect and altered cross-modal interactions in audiovisual perception; and (5) auditory localization manifested as impaired spatial hearing as a result of abnormal developmental calibration of the auditory map. To detect amblyopia early, a targeted approach is required to identify children from low-income families through in-school visual screening, supplemented by follow-up care and free eyeglasses in high-needs schools.

ISL1 is necessary for auditory neuron development and contributes toward tonotopic organization.

A cardinal feature of the auditory pathway is frequency selectivity, represented in a tonotopic map from the cochlea to the cortex. The molecular determinants of the auditory frequency map are unknown. Here, we discovered that the transcription factor ISL1 regulates the molecular and cellular features of auditory neurons, including the formation of the spiral ganglion and peripheral and central processes that shape the tonotopic representation of the auditory map. We selectively knocked out Isl1 in auditory neurons using Neurod1Cre strategies. In the absence of Isl1, spiral ganglion neurons migrate into the central cochlea and beyond, and the cochlear wiring is profoundly reduced and disrupted. The central axons of Isl1 mutants lose their topographic projections and segregation at the cochlear nucleus. Transcriptome analysis of spiral ganglion neurons shows that Isl1 regulates neurogenesis, axonogenesis, migration, neurotransmission-related machinery, and synaptic communication patterns. We show that peripheral disorganization in the cochlea affects the physiological properties of hearing in the midbrain and auditory behavior. Surprisingly, auditory processing features are preserved despite the significant hearing impairment, revealing central auditory pathway resilience and plasticity in Isl1 mutant mice. Mutant mice have a reduced acoustic startle reflex, altered prepulse inhibition, and characteristics of compensatory neural hyperactivity centrally. Our findings show that ISL1 is one of the obligatory factors required to sculpt auditory structural and functional tonotopic maps. Still, upon Isl1 deletion, the ensuing central plasticity of the auditory pathway does not suffice to overcome developmentally induced peripheral dysfunction of the cochlea.

EVALUATION OF A NON-VISUAL AUDITORY CHOROPLETH AND TRAVEL MAP VIEWER.

The auditory virtual reality interface of Audiom, a web-based map viewer, was evaluated by thirteen blind participants. In Audiom, the user is an avatar that navigates, using the arrow keys, through geographic data, as if they are playing a first-person, egocentric game. The research questions were: What will make blind users want to use Audiom maps? And Can participants demonstrate basic acquisition of spatial knowledge after viewing an auditory map? A dynamic choropleth map of state-level US COVID-19 data, and a detailed OpenStreetMap powered travel map, were evaluated. All participants agreed they wanted more maps of all kinds, in particular county-level COVID data, and they would use Audiom once some bugs were fixed and their few recommended features were added. Everyone wanted to see Audiom embedded in their existing travel and mapping applications. All participants were able to answer a question evaluating spatial knowledge. Participants also agreed this spatial information was not available in existing applications.

Sound Localization of World and Head-Centered Space in Ferrets.

The location of sounds can be described in multiple coordinate systems that are defined relative to ourselves, or the world around us. Evidence from neural recordings in animals point towards the existence of both head-centered and world-centered representations of sound location in the brain; however, it is unclear whether such neural representations have perceptual correlates in the sound localization abilities of non-human listeners. Here, we establish novel behavioral tests to determine the coordinate systems in which ferrets can localize sounds. We found that ferrets could learn to discriminate between sound locations that were fixed in either world-centered or head-centered space, across wide variations in sound location in the alternative coordinate system. Using probe sounds to assess broader generalization of spatial hearing, we demonstrated that in both head and world-centered tasks, animals used continuous maps of auditory space to guide behavior. Single trial responses of individual animals were sufficiently informative that we could then model sound localization using speaker position in specific coordinate systems and accurately predict ferrets’ actions in held-out data. Our results indicate that an animal model in which neurons are known to be tuned to sound location in egocentric and allocentric reference frames can also localize sounds in multiple head and world-centered spaces.

Intraoperative seizures occurrence in cortical mapping of eloquent areas

The effect of structural epilepsy on the frequency of intraoperative convulsive seizures is assessed when mapping functionally significant areas of the cerebral cortex during resection of intracerebral neoplasms. The work is based on the analysis of the results of intraoperative neurophysiological studies at the Polenov Neurosurgical Institute. For the period 20192020 87 intraoperative mappings of eloquent cortex were carried out during resections of intracerebral neoplasms: 79 mappings of the motor cortex and 16 mappings of auditory-speech areas during operations with awakening. When mapping the motor zones of the cortex, the frequency of seizures was 5.1%, while mapping the auditory-speech zones with awakening 18.75%. The division of cases of intraoperative convulsive seizures into two groups: seizures arising from motor mapping and seizures associated with the mapping of auditory zones reflects differences in factors that affect the excitability of the cerebral cortex. In motor mapping, stimulation occurs against the background of general anesthesia, unlike waking operations. The intensity of stimulation in auditory mapping is higher than in motor mapping in motor mapping. Formally, the current used in motor mapping is significantly higher than in mapping auditory zones. In general, with the development of intraoperative convulsive seizures, the current intensity of cortical stimulation does not exceed the average values required to stimulate functionally significant cortical zones. The presence of epileptic syndrome in patients with intracerebral tumors cannot be considered as a predictor of intraoperative seizure development when performing motor mapping under general anesthesia as well as during surgery with awakening for mapping of motor or auditory verbal zones.

Exploring the dimensions of everyday soundscapes perception in spatiotemporal view: A qualitative approach

Soundscape measurement has gained attention from researchers across a variety of disciplines and professions. The aim of this study was to explore everyday soundscapes properties as perceived by non-experts and construct a soundscape perception model in the spatiotemporal view and landscape tradition. This study used the conceptual framework of an existing landscape model to construct a soundscape evaluation scale based on the qualitative analysis of 490 semi-structured questionnaires. The evaluation scale has five fundamental dimensions: Perceptible Sound Characteristics, Perceptual Time, Perceptual Place, Audience Subjectivity, and Auditory Imagination. There are 18 primary indexes and 35 secondary indexes. The results indicated that the public’s perception schema of soundscape was similar to that of visual landscape, but had more emotional aspects. Thus, the soundscape can produce abundant auditory mapping in the mind through the involvement of the auditory organs and subsequent cognitive processing and people can provide efficient evolution of the perceptible sound environment as feedback.

Utilizing laser distance sensors for audio recovery and acoustic source localization

Previous research has shown that we can measure the acoustic displacement of a surface with a laser to recover audio inside a room, but these were not done with modern laser distance measurement methods. One such method, LIDAR, has the potential for acoustic recovery, allowing for a room's visual and auditory mapping to be done with one device. With audio recovery through an ideal spinning LIDAR, we would not only obtain the sound inside the room, but we should be able to localize an acoustic source through sampling points around a room. We define the parameters required for a single-point light distance sensor to record audio and compare our results to a light distance sensor used in manufacturing. We also show the parameters that a spinning LIDAR device needs for acoustic source localization and draw a comparison to what is currently available today.

Auditory Mapping With MEG: An Update on the Current State of Clinical Research and Practice With Considerations for Clinical Practice Guidelines.

Auditory evoked fields (AEFs) are well suited for studies of auditory processing in patients. Their sources have been localized to Heschl's gyri and to the supratemporal auditory cortices. Auditory evoked fields are known to be modulated by peripheral and central lesions of auditory pathways and to reflect group-level pathophysiology of neurodevelopmental and psychiatric disorders. They are useful in lateralization of language processes for planning neurosurgery and for localization of language-related cortex. The recently developed artifact rejection and movement compensation methods will enhance and extend the use of AEFs in studies of clinical patients and pediatric groups. New pediatric magnetoencephalography systems will facilitate clinical AEF studies of developmental disorders. In addition to their established use in planning neurosurgery, AEF findings in several new clinical patient groups suffering, e.g., from developmental, neurodegenerative, or psychiatric disorders have been reported. Several recent investigations report the correlations with clinical symptoms and sensitivity and specificity profiles of AEFs in studies of these disorders; this development is mandatory in gaining wider clinical approval for the use of AEFs in clinical practice dealing with individual patients. Most promising future research lines of clinical applicability of AEFs focus on developmental and psychiatric disorders.

Auditory versus visual spatial stimulus-response mappings in tracking and discrete dual task performance: implications for human-machine interface design

A discrete four-choice response task with auditory signal presentation and a joystick-controlled visual tracking task was used to investigate how spatial compatibility influences the dual-task performance of different display-control settings. It was found that the more incompatible the stimulus-response mapping, the longer the delay for both tasks, presumably because of the longer stimulus encoding time required for the incompatible conditions. A comparison of the findings of this study with those of past experiments on visual visual setting shows that the dual-task performance in a cross-modality (auditory visual) setting was significantly better than that in an intra-modality (visual visual) setting because of visual scanning required in the intra-modal dual tasks. However, when the locations of visual visual tasks were close enough such that ambient and focal vision was concurrently used for information processing, the dual-task performance of intra-modality (visual visual) configuration was slightly better than that of the cross-modality (auditory visual) configuration. Practitioner Summary: The effect of spatial compatibility with auditory signal presentation in multiple display-control configurations was examined in a dual-task paradigm. The results provided important and useful ergonomics design implications and consequent recommendations for intra- and cross- modal interface design. The results should facilitate human-machine system design and improve overall system performance.

Pharmacological DNA Demethylation Weakens Inhibitory Synapses in the Auditory Cortex and Re-opens the Critical Period for Frequency Map Plasticity

The critical period is a time of maximal plasticity within the cortex. The progression of the critical period is marked by experience-dependent transcriptional alterations in cortical neurons, which in turn shifts the excitatory-inhibitory balance in the brain, and accordingly reduces plasticity. Epigenetic mechanisms, such as DNA methylation, control the transcriptional state of neurons, and have been shown to be dynamically regulated during the critical period. Here we show that adult animals have a significantly higher concentration of DNA methylation than critical period animals. Pharmacological reduction of DNA methylation in adult animals re-establishes critical period auditory map plasticity. Furthermore, the reduction of DNA methylation in adult animals, reverted intrinsic characteristics of inhibitory synapses to an immature state. Our data suggest that accumulation of DNA methylation during the critical period confers a mature phenotype to cortical neurons, which in turn, facilitates the reduction in plasticity seen after the critical period.

Predictors of chronicity in alcohol use disorder: an evoked response potential study

Introduction Evoked response potentials (ERP) can reliably map key neurocognitive processes which are putatively responsible for chronic alcohol use disorder (AUD). Aim of the present study was to study P300 auditory odd ball and N400 visual semantic incongruity paradigm mapping executive functions rubric as a potential biomarker predicting chronicity in AUDs. Methodology: 60 right handed 18 to 54 years age subjects were divided into chronic “CAD” and non chronic alcohol dependence “NAD” in addition to healthy control “HC” (N = 30). Subjects were assessed by Addiction Severity Index (ASI), P300 auditory odd ball paradigm in midline region and visual N400 semantic incongruity task in centro-parietal region in a cross sectional design. Results: All the three groups differed significantly for P300 and N400 amplitude in all the leads with maximum attenuation seen in CAD. On discriminant function analysis (DFA), P300 Pz and N 400 C2 amplitude values could accurately classified 78.3% subjects. Composite sensitivity and specificity of the two predictor variables differentiating CAD subjects from NAD were 79.31 and 77.41%. receiver operating characteristic curve generated an area under the curve of .758 and .847 i.e., “fair to good” ability to predict CAD from NAD. Conclusion: We conclude that specific ERP paradigm can be used as a state marker to map the cognitive deficits and as a biomarker to detect chronic AUDs.

DESIGN AND EVALUATION OF AN AUDIO GAME-INSPIRED AUDITORY MAP INTERFACE.

This study evaluated a web-based auditory map prototype built utilizing conventions found in audio games and presents findings from a set of tasks participants performed with the prototype. The prototype allowed participants to use their own computer and screen reader, contrary to most studies, which restrict use to a single platform and a self-voicing feature (providing a voice that talks by default). There were three major findings from the tasks: the interface was extremely easy to learn and navigate, participants all had unique navigational styles and preferred using their own screen reader, and participants needed user interface features that made it easier to understand and answer questions about spatial properties and relationships. Participants gave an average task load score of 39 from the NASA Task Load Index and gave a confidence level of 46/100 for actually using the prototype to physically navigate.

Pre-Navigation via Interactive Audio Tactile Maps to Promote the Wellbeing of Visually Impaired People.

Pre-navigational tools can assist visually impaired people when navigating unfamiliar environments. Assistive technology products (eg tactile maps or auditory simulations) can stimulate cognitive mapping processes to provide navigational assistance in these people. We compared how well blind and visually impaired people could learn a map presented via a tablet computer auditory tactile map (ATM) in contrast to a conventional tactile map accompanied by a text description objectives. Performance was assessed with a multiple choice test that quizzed participants on orientation and spatial awareness. Semi-structured interviews explored participant experiences and preferences. A statistically significant difference was found between the conditions with participants using the ATM performing much better than those who used a conventional tactile map and text description. Participants preferred the flexibility of learning of the ATM. This computer-based ATM provided an effective, easy to use and cost-effective way of enabling blind and partially sighted people learn a cognitive map and enhance their wellbeing.

Impaired Spatial Hearing in Amblyopia: Evidence for Calibration of Auditory Maps by Retinocollicular Input in Humans.

Evidence from animals and blind humans suggests that early visual experience influences the developmental calibration of auditory localization. Hypothesizing that unilateral amblyopia may involve cross-modal deficits in spatial hearing, we measured the precision and accuracy of sound localization in humans with amblyopia. All participants passed a standard hearing test. Experiment 1 measured sound localization precision for click stimuli in 10 adults with amblyopia and 10 controls using a minimum audible angle (MAA) task. Experiment 2 measured sound localization error (i.e., accuracy) for click train stimuli in 14 adults with amblyopia and 16 controls using an absolute sound localization task. In Experiment 1, the MAA (mean ± SEM) was significantly greater in the amblyopia group compared with controls (2.75 ± 0.30° vs. 1.69 ± 0.09°, P = 0.006). In Experiment 2, the overall sound localization error was significantly greater in the amblyopia group compared with controls (P = 0.047). The amblyopia group also showed significantly greater sound localization error in the auditory hemispace ipsilateral to the amblyopic eye (P = 0.036). At a location within this auditory hemispace, the magnitude of sound localization error correlated significantly with deficits in stereo acuity (P = 0.036). The precision and accuracy of sound localization are impaired in unilateral amblyopia. The asymmetric pattern of sound localization error suggests that amblyopic vision may interfere with the development of spatial hearing via the retinocollicular pathway.

An audio attention computational model based on information entropy of two channels and exponential moving average

The main down-top attention model usually uses some characteristics of audio signal to extract the auditory saliency map at present. But existing audio attention computational model based image saliency mostly doesn’t consider the continuity and attenuation mechanism of the human brain on paying attention to some occurred events in our real environment. To address these issues, we propose a model based on information entropy of two channels and exponential moving average (EMA) to simulate the processing of sound signals from the basilar membrane to the cochlear nucleus, and get the local information entropy of image and audio channel, finally we use the relevant EMA methods to calculate the auditory attention map. Some experimental results on artificial audio signal and real-world audio signal belonging to a public corpus show that the proposed model not only can detect the attention event, but also reflect the mechanism of human brain, and the experimental results of talk show in real environment are better.

A Software Tool for the Experimental Investigation of Cognitive Effects in Audiovisual Maps

The increasing importance of cognitively oriented visualization in cartography implies the use of modern approaches of experimental user studies. Such experiments are usually standardized, and researchers try to avoid confounding factors as much as possible. Therefore, modern experimental studies are based on digital, software-based methods and techniques to fulfil the demands. A set of established standard software exists which can partly be adopted to individual research questions in cartography and spatial cognition. However, these tools have not primarily been developed for the field of cartography and, thus, cartographic peculiarities are missing. For example, this can be related to the implementation of multimedia, incl. auditory (map) stimuli to investigate the impact of specific sound elements on cognitive processing in audiovisual cartography. This may also refer to the way (behavioural) user data measured during spatial tasks in maps are presented to the analyst. To make use of a more cartography-focused study software which can be used in map-based studies on spatial memory performance, an individual software tool was programmed. The tool is based on the object-oriented programming language ActionScript 3.0 and allows an easy customization due to its simplicity. The tool can be exported in the runtime system Adobe AIR and is highly suitable for lab studies. This paper presents some functionalities and peculiarities of this tool, including several examples of the written and commented scripting code.

Audiovisual Cartography: Established and New Multimedia Approaches to Represent Soundscapes

Since the mid-1990s, sound has been discussed and used in multimedia cartography. There are four main variants of auditory map elements that have been established in the theory and practice of audiovisual cartography, i.e. abstract sounds/abstract sound sequences, speech, music and, especially, audiorealistic sequences representing so-called “soundscapes”. In cartography, soundscapes are often addressed in large-scale representations. The term originates in multidisciplinary landscape research. Empirical findings of landscape research, and especially those of social constructivist landscape research, have shown the relevance of non-visual stimuli for people’s individual impressions and meanings of the experienced landscape. Amongst the non-visual landscape dimensions, the auditory dimension is the most prominent one. As 3D cartography offers new methods and techniques of designing and experiencing highly realistic, incl. photo- and audiorealistic landscape representation, this discipline becomes more and more interesting for simulating and presenting multisensory landscapes and for presenting the results of empirical findings in landscape research. After an introduction to traditional means of audiovisual cartography and the relevance of auditory stimuli for social constructivist approaches of landscape research, a modern software-based method is presented which highlights the opportunity to imbed 3D sound data representing a location’s soundscape into audiovisual 3D environments in Virtual Reality (VR). It is technically based on the cross-platform game engine Unity3D.

Neurod1 Is Essential for the Primary Tonotopic Organization and Related Auditory Information Processing in the Midbrain.

Hearing depends on extracting frequency, intensity, and temporal properties from sound to generate an auditory map for acoustical signal processing. How physiology intersects with molecular specification to fine tune the developing properties of the auditory system that enable these aspects remains unclear. We made a novel conditional deletion model that eliminates the transcription factor NEUROD1 exclusively in the ear. These mice (both sexes) develop a truncated frequency range with no neuroanatomically recognizable mapping of spiral ganglion neurons onto distinct locations in the cochlea nor a cochleotopic map presenting topographically discrete projections to the cochlear nuclei. The disorganized primary cochleotopic map alters tuning properties of the inferior colliculus units, which display abnormal frequency, intensity, and temporal sound coding. At the behavioral level, animals show alterations in the acoustic startle response, consistent with altered neuroanatomical and physiological properties. We demonstrate that absence of the primary afferent topology during embryonic development leads to dysfunctional tonotopy of the auditory system. Such effects have never been investigated in other sensory systems because of the lack of comparable single gene mutation models.SIGNIFICANCE STATEMENT All sensory systems form a topographical map of neuronal projections from peripheral sensory organs to the brain. Neuronal projections in the auditory pathway are cochleotopically organized, providing a tonotopic map of sound frequencies. Primary sensory maps typically arise by molecular cues, requiring physiological refinements. Past work has demonstrated physiologic plasticity in many senses without ever molecularly undoing the specific mapping of an entire primary sensory projection. We genetically manipulated primary auditory neurons to generate a scrambled cochleotopic projection. Eliminating tonotopic representation to auditory nuclei demonstrates the inability of physiological processes to restore a tonotopic presentation of sound in the midbrain. Our data provide the first insights into the limits of physiology-mediated brainstem plasticity during the development of the auditory system.