Capturing contextual effects in spectro-temporal receptive fields.
PJ Abstract Spectro-temporal receptive fields (STRFs) are thought to provide descriptive images of the computations performed by neurons along the auditory pathway. However, their validity can be questioned because they rely on a set of assumptions that are probably not fulfilled by real neurons exhibiting contextual effects, that is, nonlinear interactions in the time or frequency dimension that cannot be described with a linear filter. We used a novel approach to investigate how a variety of contextual effects, due to facilitating nonlinear interactions and synaptic depression, affect different STRF models, and...
Source: Hearing Research - July 26, 2016 Category: Audiology Authors: Westö J, May PJ Tags: Hear Res Source Type: research
Atypical white-matter microstructure in congenitally deaf adults: a region of interest and tractography study using diffusion-tensor imaging.
Abstract Considerable research documents the cross-modal reorganization of auditory cortices as a consequence of congenital deafness, with remapped functions that include visual and somatosensory processing of both linguistic and nonlinguistic information. Structural changes accompany this cross-modal neuroplasticity, but precisely which specific structural changes accompany congenital and early deafness and whether there are group differences in hemispheric asymmetries remain to be established. Here, we used diffusion tensor imaging (DTI) to examine microstructural white matter changes accompanying cross-modal re...
Source: Hearing Research - July 26, 2016 Category: Audiology Authors: Karns CM, Stevens C, Dow MW, Schorr E, Neville HJ Tags: Hear Res Source Type: research
Acoustic input impedance of the avian inner ear measured in ostrich (Struthio camelus).
In this study, the aim was to quantify the acoustic impedance of the avian inner ear in the ostrich, which allows us to determine the effect on columellar vibrations and middle ear power flow in future studies. To determine the inner ear impedance, vibrations of the columella were measured for both the quasi-static and acoustic stimulus frequencies. In the frequency range of 0.3-4 kHz, we used electromagnetic stimulation of the ossicle and a laser Doppler vibrometer to measure the vibration response. At low frequencies, harmonic displacements were imposed on the columella using piezo stimulation and the resulting force res...
Source: Hearing Research - July 26, 2016 Category: Audiology Authors: Muyshondt PG, Aerts P, Dirckx JJ Tags: Hear Res Source Type: research
Seasonal variations in auditory processing in the inferior colliculus of Eptesicus fuscus.
Abstract Eptesicus fuscus is typical of temperate zone bats in that both sexes undergo marked seasonal changes in behavior, endocrine status, and reproductive status. Acoustic communication plays a key role in many seasonal behaviors. For example, males emit specialized vocalizations during mating in the fall, and females use different specialized vocalizations to communicate with infants in late spring. Bats of both sexes use echolocation for foraging during times of activity, but engage in little sound-directed behavior during torpor and hibernation in winter. Auditory processing might be expected to reflect the...
Source: Hearing Research - July 26, 2016 Category: Audiology Authors: Miller KE, Barr K, Krawczyk M, Covey E Tags: Hear Res Source Type: research
Neurofilament heavy chain expression and neuroplasticity in rat auditory cortex after unilateral and bilateral deafness.
Abstract Deafness induces many plastic changes in the auditory neural system. For instance, dendritic changes cause synaptic changes in neural cells. SMI-32, a monoclonal antibody reveals auditory areas and recognizes non-phosphorylated epitopes on medium- and high-molecular-weight subunits of neurofilament proteins in cortical pyramidal neuron dendrites. We investigated SMI-32-immunoreactive (-ir) protein levels in the auditory cortices of rats with induced unilateral and bilateral deafness. Adult male Sprague-Dawley rats were divided into unilateral deafness (UD), bilateral deafness (BD), and control groups. Dea...
Source: Hearing Research - July 22, 2016 Category: Audiology Authors: Park MH, Jang JH, Song JJ, Lee HS, Oh SH Tags: Hear Res Source Type: research
Speech-evoked activation in adult temporal cortex measured using functional near-infrared spectroscopy (fNIRS): Are the measurements reliable?
Abstract Functional near-infrared spectroscopy (fNIRS) is a silent, non-invasive neuroimaging technique that is potentially well suited to auditory research. However, the reliability of auditory-evoked activation measured using fNIRS is largely unknown. The present study investigated the test-retest reliability of speech-evoked fNIRS responses in normally-hearing adults. Seventeen participants underwent fNIRS imaging in two sessions separated by three months. In a block design, participants were presented with auditory speech, visual speech (silent speechreading), and audiovisual speech conditions. Optode arrays w...
Source: Hearing Research - July 21, 2016 Category: Audiology Authors: Wiggins IM, Anderson CA, Kitterick PT, Hartley DE Tags: Hear Res Source Type: research
Volumes of Cochlear Nucleus Regions in Rodents.
Abstract The cochlear nucleus receives all the coded information about sound from the cochlea and is the source of auditory information for the rest of the central auditory system. As such, it is a critical auditory nucleus. The sizes of the cochlear nucleus as a whole and its three major subdivisions - anteroventral cochlear nucleus (AVCN), posteroventral cochlear nucleus (PVCN), and dorsal cochlear nucleus (DCN) - have been measured in a large number of mammals, but measurements of its subregions at a more detailed level for a variety of species have not previously been made. Size measurements are reported here ...
Source: Hearing Research - July 16, 2016 Category: Audiology Authors: Godfrey DA, Lee AC, Hamilton WD, Benjamin LC, Vishwanath S, Simo H, Godfrey LM, Mustapha AI, Heffner RS Tags: Hear Res Source Type: research
Response to Letter: Whole scalp EEG power change is not a prerequisite for further EEG processing.
PMID: 27426297 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 14, 2016 Category: Audiology Authors: Hall DA, Pierzycki RH, Hoare DJ, McNamara AJ Tags: Hear Res Source Type: research
Whole scalp EEG power change is not a prerequisite for further EEG processing.
PMID: 27424300 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 14, 2016 Category: Audiology Authors: De Ridder D, Congedo M, Song JJ, Vanneste S Tags: Hear Res Source Type: research
Reprint of: Immune defense is the primary function associated with the differentially expressed genes in the cochlea following acoustic trauma.
Abstract Our previous RNA-sequencing analysis of the rat cochlear genes identified multiple biological processes and molecular pathways in the cochlear response to acoustic overstimulation. However, the biological processes and molecular pathways that are common to other species have not been documented. The identification of these common stress processes is pivotal for a better understanding of the essential response of the cochlea to acoustic injury. Here, we compared the RNA-sequencing data collected from mice and rats that sustained a similar, but not identical, acoustic injury. The transcriptome analysis of c...
Source: Hearing Research - July 9, 2016 Category: Audiology Authors: Yang S, Cai Q, Vethanayagam RR, Wang J, Yang W, Hu BH Tags: Hear Res Source Type: research
Crossmodal plasticity in auditory, visual and multisensory cortical areas following noise-induced hearing loss in adulthood.
Abstract Complete or partial hearing loss results in an increased responsiveness of neurons in the core auditory cortex of numerous species to visual and/or tactile stimuli (i.e., crossmodal plasticity). At present, however, it remains uncertain how adult-onset partial hearing loss affects higher-order cortical areas that normally integrate audiovisual information. To that end, extracellular electrophysiological recordings were performed under anesthesia in noise-exposed rats two weeks post-exposure (0.8-20 kHz at 120 dB SPL for 2 h) and age-matched controls to characterize the nature and extent of crossmodal plas...
Source: Hearing Research - July 4, 2016 Category: Audiology Authors: Schormans AL, Typlt M, Allman BL Tags: Hear Res Source Type: research
Place dependent stimulation rates improve pitch perception in cochlear implantees with single-sided deafness.
aumann U Abstract In normal hearing, the pitch of an acoustic tone can theoretically be encoded by either the place of stimulation in the cochlea or the corresponding rate of vibration. Thus spectral attributes and temporal fine structure of an acoustic signal are naturally correlated. Cochlear implants (CIs), neural prosthetic devices that restore hearing in the profoundly hearing impaired, currently disregard this mechanism; electrical stimulation is provided at fixed electrode positions with default place independent stimulation rate assignments. This does not account for individual cochlear encoding depending ...
Source: Hearing Research - July 1, 2016 Category: Audiology Authors: Rader T, Döge J, Adel Y, Weißgerber T, Baumann U Tags: Hear Res Source Type: research
Endolymph Movement Visualized with Light Sheet Fluorescence Microscopy in an Acute Hydrops Model.
Abstract There are a variety of techniques available to investigate endolymph dynamics, primarily seeking to understand the cause of endolymphatic hydrops. Here we have taken the novel approach of injecting, via a glass micropipette, fluorescein isothiocyanate-dextran (FITC-dex) + artificial endolymph into scala media of anaesthetized guinea pigs, with subsequent imaging of the inner ear using Light Sheet Fluorescence Microscopy (LSFM) as a means to obtain highly resolved 3D visualization of fluid movements. Our results demonstrate endolymph movement into the utricle, semicircular canals and endolymphatic duct and...
Source: Hearing Research - July 1, 2016 Category: Audiology Authors: Brown DJ, Pastras C, Curthoys IS, Southwell CS, Van Roon L Tags: Hear Res Source Type: research
Subcortical correlates of auditory perceptual organization in humans.
Abstract To make sense of complex auditory scenes, the auditory system sequentially organizes auditory components into perceptual objects or streams. In the conventional view of this process, the cortex plays a major role in perceptual organization, and subcortical mechanisms merely provide the cortex with acoustical features. Here, we show that the neural activities of the brainstem are linked to perceptual organization, which alternates spontaneously for human listeners without any stimulus change. The stimulus used in the experiment was an unchanging sequence of repeated triplet tones, which can be interpreted ...
Source: Hearing Research - June 29, 2016 Category: Audiology Authors: Yamagishi S, Otsuka S, Furukawa S, Kashino M Tags: Hear Res Source Type: research
Correlation between word recognition score and intracochlear new bone and fibrous tissue after cochlear implantation in the human.
Abstract Cochlear implantation is an effective, established procedure for patients with profound deafness. Although implant electrodes have been considered as biocompatible prostheses, surgical insertion of the electrode induces various changes within the cochlea. Immediate changes include insertional trauma to the cochlea. Delayed changes include a tissue response consisting of inflammation, fibrosis and neo-osteogenesis induced by trauma and an immunologic reaction to a foreign body. The goal of this study was to evaluate the effect of these delayed changes on the word recognition scores achieved post-operativel...
Source: Hearing Research - June 29, 2016 Category: Audiology Authors: Kamakura T, Nadol JB Tags: Hear Res Source Type: research
Prepulse inhibition of the acoustic startle reflex vs. auditory brainstem response for hearing assessment.
Abstract The high prevalence of noise-induced and age-related hearing loss in the general population has warranted the use of animal models to study the etiology of these pathologies. Quick and accurate auditory threshold determination is a prerequisite for experimental manipulations targeting hearing loss in animal models. The standard auditory brainstem response (ABR) measurement is fairly quick and translational across species, but is limited by the need for anesthesia and a lack of perceptual assessment. The goal of this study was to develop a new method of hearing assessment utilizing prepulse inhibition (PPI...
Source: Hearing Research - June 24, 2016 Category: Audiology Authors: Longenecker RJ, Alghamdi F, Rosen MJ, Galazyuk AV Tags: Hear Res Source Type: research
On the method of Hunt's parameter calibration.
Abstract This note comments on the observations of Bernier et al. (2016) regarding errors in Appendix A of Kim and Allen (2013). We acknowledge that the equations in the Appendix are in error, but wish to point out that these equations were not actually used for our analysis. We appreciate their effort in pointing out the errors, and offering corrected equations. PMID: 27343569 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 23, 2016 Category: Audiology Authors: Kim N, Allen J Tags: Hear Res Source Type: research
White Matter Structure in the right Planum Temporale Region Correlates with Visual Motion Detection Thresholds in Deaf People.
Abstract The right planum temporale region is typically involved in higher-order auditory processing. After deafness, this area reorganizes to become sensitive to visual motion. This plasticity is thought to support compensatory enhancements to visual ability. In earlier work we showed that enhanced visual motion detection abilities in early-deaf people correlate with cortical thickness in a subregion of the right planum temporale. In the current study, we build on this earlier result by examining the relationship between enhanced visual motion detection ability and white matter structure in this area in the same ...
Source: Hearing Research - June 16, 2016 Category: Audiology Authors: Shiell MM, Zatorre RJ Tags: Hear Res Source Type: research
Neural response differences in the rat primary auditory cortex under anesthesia with ketamine versus the mixture of medetomidine, midazolam and butorphanol.
Abstract Anesthesia affects central auditory processing. However, it is unclear to what extent the choice of anesthetic agent affects neural responses to sound stimulation. A mixture of three anesthetics (medetomidine, midazolam and butorphanol; MMB) was recently developed as an alternative to ketamine owing to the latter's addictive potential, yet the effect of this combination of anesthetics on neural responses is not known. Here, we compared the spontaneous activity, tuning properties and temporal responses of primary auditory cortical neurons under these two anesthetic conditions, using electrophysiological an...
Source: Hearing Research - June 16, 2016 Category: Audiology Authors: Osanai H, Tateno T Tags: Hear Res Source Type: research
A Combination of Two Truncating Mutations in USH2A causes more Severe and Progressive Hearing Impairment in Usher syndrome type IIa.
CONCLUSIONS: The results have direct implications for patient counselling in terms of prognosis of hearing and may serve as baseline measures for future (genetic) therapeutic interventions. PMID: 27318125 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 15, 2016 Category: Audiology Authors: Hartel BP, Löfgren M, Huygen PL, Guchelaar I, Lo-A-Njoe Kort N, Sadeghi AM, van Wijk E, Tranebjærg L, Kremer H, Kimberling WJ, Cremers CW, Möller C, Pennings RJ Tags: Hear Res Source Type: research
Comment on Two-port network analysis and modeling of a balanced armature receiver.
PMID: 27318126 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 15, 2016 Category: Audiology Authors: Bernier A, Herzog P, Voix J Tags: Hear Res Source Type: research
Origins of thalamic and cortical projections to the posterior auditory field in congenitally deaf cats.
Abstract Crossmodal plasticity takes place following sensory loss, such that areas that normally process the missing modality are reorganized to provide compensatory function in the remaining sensory systems. For example, congenitally deaf cats outperform normal hearing animals on localization of visual stimuli presented in the periphery, and this advantage has been shown to be mediated by the posterior auditory field (PAF). In order to determine the nature of the anatomical differences that underlie this phenomenon, we injected a retrograde tracer into PAF of congenitally deaf animals and quantified the thalamic ...
Source: Hearing Research - June 12, 2016 Category: Audiology Authors: Butler BE, Chabot N, Kral A, Lomber SG Tags: Hear Res Source Type: research
Species-dependent role of crossmodal connectivity among the primary sensory cortices.
Abstract When a major sense is lost, crossmodal plasticity substitutes functional processing from the remaining, intact senses. Recent studies of deafness-induced crossmodal plasticity in different subregions of auditory cortex indicate that the phenomenon is largely based on the "unmasking" of existing inputs. However, there is not yet a consensus on the sources or effects of crossmodal inputs to primary sensory cortical areas. In the present review, a rigorous re-examination of the experimental literature indicates that connections between different primary sensory cortices consistently occur in rodent...
Source: Hearing Research - June 9, 2016 Category: Audiology Authors: Meredith MA, Lomber SG Tags: Hear Res Source Type: research
Neural correlates of auditory scale illusion.
In this study, we conducted functional magnetic resonance imaging using sequential tones that induced scale illusion (ILL) and those that mimicked the percept of scale illusion (PCP), and we compared the activation responses evoked by those stimuli by region-of-interest analysis. We examined the effects of adaptation, i.e., the attenuation of response that occurs when close-frequency sounds are repeated, which might interfere with the changes in activation by the illusion process. Results of the activation difference of the two stimuli, measured at varied tempi of tone presentation, in the superior temporal auditory cortex...
Source: Hearing Research - June 9, 2016 Category: Audiology Authors: Kuriki S, Numao R, Nemoto I Tags: Hear Res Source Type: research
Postnatal maturation of auditory-nerve response heterogeneity as seen in spatial gradients of synapse morphology in the inner hair cell area.
Abstract Auditory nerve fibers in the adult ear are divided into functional subgroups according to spontaneous rate (SR) and threshold sensitivity. The high-threshold, low-SR fibers are morphologically and spatially distinct from the low-threshold high-SR fibers at their synaptic contacts with inner hair cells. This distinction between SR groups in the adult ear is visible in confocal microscopy as complementary size gradients of presynaptic ribbons and post-synaptic glutamate receptor patches across the modiolar-pillar and habenular-cuticular axes in the inner hair cell area. The aim of the present study was to t...
Source: Hearing Research - June 8, 2016 Category: Audiology Authors: Liberman LD, Liberman MC Tags: Hear Res Source Type: research
Neural indices of phonemic discrimination and sentence-level speech intelligibility in quiet and noise: A mismatch negativity study.
Abstract Successful speech communication requires the extraction of important acoustic cues from irrelevant background noise. In order to better understand this process, this study examined the effects of background noise on mismatch negativity (MMN) latency, amplitude, and spectral power measures as well as behavioral speech intelligibility tasks. Auditory event-related potentials (AERPs) were obtained from 15 normal-hearing participants to determine whether pre-attentive MMN measures recorded in response to a consonant and vowel change in a double-oddball paradigm can predict sentence-level speech perception. Th...
Source: Hearing Research - June 4, 2016 Category: Audiology Authors: Koerner TK, Zhang Y, Nelson P, Wang B, Zou H Tags: Hear Res Source Type: research
Membrane prestin expression correlates with the magnitude of prestin-associated charge movement.
Abstract Full expression of electromotility, generation of non-linear capacitance (NLC), and high-acuity mammalian hearing require prestin function in the lateral wall of cochlear outer hair cells (OHCs). Estimates of the number of prestin molecules in the OHC membrane vary, and a consensus has not emerged about the correlation between prestin expression and prestin-associated charge movement in the OHC. Using an inducible prestin-expressing cell line, we demonstrate that the charge density, but not the voltage at peak capacitance, directly correlates with the amount of prestin in the plasma membrane. This correla...
Source: Hearing Research - June 1, 2016 Category: Audiology Authors: Seymour ML, Rajagopalan L, Duret G, Volk MJ, Liu H, Brownell WE, Pereira FA Tags: Hear Res Source Type: research
Origin of the Thalamic Projection to Dorsal Auditory Cortex in Hearing and Deafness.
Abstract While it is now well accepted that the brain reorganizes following sensory loss, the neural mechanisms that give rise to this plasticity are not well understood. Anatomical tract tracing studies have begun to shed light on the structural underpinnings of cross-modal reorganization by comparing cerebral connectivity in sensory-deprived animals to that of their non-deprived counterparts. However, so far, full documentation of connectional patterns within hearing, congenitally deaf, as well as animals deafened early versus later in life exist only for primary auditory cortex, a region not known to undergo cr...
Source: Hearing Research - June 1, 2016 Category: Audiology Authors: Kok MA, Lomber SG Tags: Hear Res Source Type: research
Detection efficiency of Auditory Steady State evoked by modulated noise.
CONCLUSION: The stimuli that include high-frequency content showed higher detection rates (>90%) and lower detection times (
Source: Hearing Research - June 1, 2016 Category: Audiology Authors: Santos TS, Silva JJ, Lins OG, Melges DB, Tierra-Criollo CJ Tags: Hear Res Source Type: research
A cool approach to reducing electrode-induced trauma: Localized therapeutic hypothermia conserves residual hearing in cochlear implantation.
Abstract OBJECTIVE: The trauma caused during cochlear implant insertion can lead to cell death and a loss of residual hair cells in the cochlea. Various therapeutic approaches have been studied to prevent cochlear implant-induced residual hearing loss with limited success. In the present study, we show the efficacy of mild to moderate therapeutic hypothermia of 4 to 6 °C applied to the cochlea in reducing residual hearing loss associated with the electrode insertion trauma. APPROACH: Rats were randomly distributed in three groups: control contralateral cochleae, normothermic implanted cochleae and hy...
Source: Hearing Research - May 31, 2016 Category: Audiology Authors: Tamames I, King C, Bas E, Dietrich WD, Telischi F, Rajguru SM Tags: Hear Res Source Type: research
Impact of peripheral hearing loss on top-down auditory processing.
Abstract The auditory system consists of an intricate set of connections interposed between hierarchically arranged nuclei. The ascending pathways carrying sound information from the cochlea to the auditory cortex are, predictably, altered in instances of hearing loss resulting from blockage or damage to peripheral auditory structures. However, hearing loss-induced changes in descending connections that emanate from higher auditory centers and project back toward the periphery are still poorly understood. These pathways, which are the hypothesized substrate of high-level contextual and plasticity cues, are intimat...
Source: Hearing Research - May 31, 2016 Category: Audiology Authors: Lesicko AM, Llano DA Tags: Hear Res Source Type: research
A systematic review of the reporting of tinnitus prevalence and severity.
CONCLUSION: Deriving global estimates of the prevalence of tinnitus involves combining results from studies which are consistent in their definition and measurement of tinnitus, survey methodology and in the reporting and analysis of the results. Ultimately comparison among studies is unachievable without such consistency. The strength of this systematic review is in providing a record of all the available, recent epidemiological data in each global region and in making recommendations for promoting standardisation. PMID: 27246985 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 28, 2016 Category: Audiology Authors: McCormack A, Edmondson-Jones M, Somerset S, Hall D Tags: Hear Res Source Type: research
Technical note for post-auricular route surgery in Mongolian gerbil.
Abstract The Mongolian gerbil (Meriones unguiculatus) is commonly used in hearing research because the hearing frequency spectrum of the gerbil is rather similar to that of the human being. However, a precise description of the surgical post-auricular route has not been reported. The aim of this technical note is to provide details on the procedure and the surgical anatomy of the post-auricular route in the Mongolian gerbil. Surgery was performed under general anesthesia on eight (2 males and 6 females) adult Mongolian gerbils. All steps of the post-auricular route were detailed. This surgery provided an access to...
Source: Hearing Research - May 28, 2016 Category: Audiology Authors: Risoud M, Bonne NX, Fourdrinier M, Hubert T, Vincent C Tags: Hear Res Source Type: research
Effect of motion on speech recognition.
Abstract The benefit of spatial separation for talkers in a multi-talker environment is well documented. However, few studies have examined the effect of talker motion on speech recognition. In the current study, we evaluated the effects of (1) motion of the target or distracters, (2) a priori information about the target and distracter spatial configurations, and (3) target and distracter location. In total, seventeen young adults with normal hearing were tested in a large anechoic chamber in two experiments. In Experiment 1, seven stimulus conditions were tested using the Coordinate Response Measure (Bolia et&nb...
Source: Hearing Research - May 27, 2016 Category: Audiology Authors: Davis TJ, Grantham DW, Gifford RH Tags: Hear Res Source Type: research
Characterization of the nonlinear elastic behavior of chinchilla tympanic membrane using micro-fringe projection.
Abstract The mechanical properties of an intact, full tympanic membrane (TM) inside the bulla of a fresh chinchilla were measured under quasi-static pressure from -1.0 kPa to 1.0 kPa applied on the TM lateral side. Images of the fringes projected onto the TM were acquired by a digital camera connected to a surgical microscope and analyzed using a phase-shift method to reconstruct the surface topography. The relationship between the applied pressure and the resulting volume displacement was determined and analyzed using a finite element model implementing a hyperelastic 2(nd)-order Ogden model. Through an inverse m...
Source: Hearing Research - May 27, 2016 Category: Audiology Authors: Liang J, Luo H, Yokell Z, Nakmali DU, Gan RZ, Lu H Tags: Hear Res Source Type: research
Auditory training improves auditory performance in cochlear implanted children.
d E Abstract While the positive benefits of pediatric cochlear implantation on language perception skills are now proven, the heterogeneity of outcomes remains high. The understanding of this heterogeneity and possible strategies to minimize it is of utmost importance. Our scope here is to test the effects of an auditory training strategy, "sound in Hands", using playful tasks grounded on the theoretical and empirical findings of cognitive sciences. Indeed, several basic auditory operations, such as auditory scene analysis (ASA) are not trained in the usual therapeutic interventions in deaf children. How...
Source: Hearing Research - May 27, 2016 Category: Audiology Authors: Roman S, Rochette F, Triglia JM, Schön D, Bigand E Tags: Hear Res Source Type: research
Acquired hearing loss and brain plasticity.
Abstract Acquired hearing loss results in an imbalance of the cochlear output across frequency. Central auditory system homeostatic processes responding to this result in frequency specific gain changes consequent to the emerging imbalance between excitation and inhibition. Several consequences thereof are increased spontaneous firing rates, increased neural synchrony, and (in adults) potentially restricted to the auditory thalamus and cortex a reorganization of tonotopic areas. It does not seem to matter much whether the hearing loss is acquired neonatally or in adulthood. In humans, no clear evidence of tonotopi...
Source: Hearing Research - May 24, 2016 Category: Audiology Authors: Eggermont JJ Tags: Hear Res Source Type: research
Functional segregation of monaural and binaural selectivity in the pallid bat auditory cortex.
Abstract Different fields of the auditory cortex can be distinguished by the extent and level tolerance of spatial selectivity. The mechanisms underlying the range of spatial tuning properties observed across cortical fields are unclear. Here, this issue was addressed in the pallid bat because its auditory cortex contains two segregated regions of response selectivity that serve two different behaviors: echolocation for obstacle avoidance and localization of prey-generated noise. This provides the unique opportunity to examine mechanisms of spatial properties in two functionally distinct regions. Previous studies ...
Source: Hearing Research - May 24, 2016 Category: Audiology Authors: Razak KA Tags: Hear Res Source Type: research
Sound coding in the auditory nerve of gerbils.
Abstract Gerbils possess a very specialized cochlea in which the low-frequency inner hair cells (IHCs) are contacted by auditory nerve fibers (ANFs) having a high spontaneous rate (SR), whereas high frequency IHCs are innervated by ANFs with a greater SR-based diversity. This specificity makes this animal a unique model to investigate, in the same cochlea, the functional role of different pools of ANFs. The distribution of the characteristic frequencies of fibers shows a clear bimodal shape (with a first mode around 1.5 kHz and a second around 12 kHz) and a notch in the histogram near 3.5 kHz. Whereas the mean thr...
Source: Hearing Research - May 21, 2016 Category: Audiology Authors: Huet A, Batrel C, Tang Y, Desmadryl G, Wang J, Puel JL, Bourien J Tags: Hear Res Source Type: research
Cochlear perfusion with a viscous fluid.
Abstract The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min...
Source: Hearing Research - May 21, 2016 Category: Audiology Authors: Wang Y, Olson ES Tags: Hear Res Source Type: research
Perceptually aligning apical frequency regions leads to more binaural fusion of speech in a CI simulation.
Abstract For bilateral cochlear implant users, the left and right arrays are typically not physically aligned, resulting in a degradation of binaural fusion, which can be detrimental to binaural abilities. Perceptually aligning the two arrays can be accomplished by disabling electrodes in one ear that do not have a perceptually corresponding electrode in the other side. However, disabling electrodes at the edges of the array will cause compression of the input frequency range into a smaller cochlear extent, which may result in reduced spectral resolution. An alternative approach to overcome this mismatch would be ...
Source: Hearing Research - May 18, 2016 Category: Audiology Authors: Staisloff HE, Lee DH, Aronoff JM Tags: Hear Res Source Type: research
Loss of glycine receptors containing the α3 subunit compromises auditory nerve activity, but not outer hair cell function.
Loss of glycine receptors containing the α3 subunit compromises auditory nerve activity, but not outer hair cell function. Hear Res. 2016 May 18; Authors: Dlugaiczyk J, Hecker D, Neubert C, Buerbank S, Campanelli D, Becker CM, Betz H, Knipper M, Rüttiger L, Schick B Abstract Inhibitory glycine receptors containing the α3 subunit (GlyRα3) regulate sensory information processing in the CNS and retina. In previous work, we demonstrated the presence of postsynaptic GlyR alpha3 immunoreactivity at efferent synapses of the medial and lateral olivocochlear bundle in the organ of Corti;...
Source: Hearing Research - May 18, 2016 Category: Audiology Authors: Dlugaiczyk J, Hecker D, Neubert C, Buerbank S, Campanelli D, Becker CM, Betz H, Knipper M, Rüttiger L, Schick B Tags: Hear Res Source Type: research
EEG activity evoked in preparation for multi-talker listening by adults and children.
Abstract Selective attention is critical for successful speech perception because speech is often encountered in the presence of other sounds, including the voices of competing talkers. Faced with the need to attend selectively, listeners perceive speech more accurately when they know characteristics of upcoming talkers before they begin to speak. However, the neural processes that underlie the preparation of selective attention for voices are not fully understood. The current experiments used electroencephalography (EEG) to investigate the time course of brain activity during preparation for an upcoming talker in...
Source: Hearing Research - May 10, 2016 Category: Audiology Authors: Holmes E, Kitterick PT, Summerfield AQ Tags: Hear Res Source Type: research
Horizontal Sound Localization in Cochlear Implant Users with a Contralateral Hearing Aid.
Abstract Interaural differences in sound arrival time (ITD) and in level (ILD) enable us to localize sounds in the horizontal plane, and can support source segregation and speech understanding in noisy environments. It is uncertain whether these cues are also available to hearing-impaired listeners who are bimodally fitted, i.e. with a cochlear implant (CI) and a contralateral hearing aid (HA). Here, we assessed sound localization behavior of fourteen bimodal listeners, all using the same Phonak HA and an Advanced Bionics CI processor, matched with respect to loudness growth. We aimed to determine the availability...
Source: Hearing Research - May 10, 2016 Category: Audiology Authors: Veugen LC, Hendrikse MM, van Wanrooij MM, Agterberg MJ, Chalupper J, Mens LH, Snik AF, John van Opstal A Tags: Hear Res Source Type: research
Aging effects on the Binaural Interaction Component of the Auditory Brainstem Response in the Mongolian Gerbil: Effects of Interaural Time and Level Differences.
Abstract The effect of interaural time difference (ITD) and interaural level difference (ILD) on wave 4 of the binaural and summed monaural auditory brainstem responses (ABRs) as well as on the DN1 component of the binaural interaction component (BIC) of the ABR in young and old Mongolian gerbils (Meriones unguiculatus) was investigated. Measurements were made at a fixed sound pressure level (SPL) and a fixed level above visually detected ABR threshold to compensate for individual hearing threshold differences. In both stimulation modes (fixed SPL and fixed level above visually detected ABR threshold) an effect of...
Source: Hearing Research - May 9, 2016 Category: Audiology Authors: Laumen G, Tollin DJ, Beutelmann R, Klump GM Tags: Hear Res Source Type: research
Long-term treatment with aldosterone slows the progression of age-related hearing loss.
Abstract Age-related hearing loss (ARHL), clinically referred to as presbycusis, is one of the three most prevalent chronic medical conditions of our elderly, with the majority of persons over the age of 60 suffering from some degree of ARHL. The progressive loss of auditory sensitivity and perceptual capability results in significant declines in workplace productivity, quality of life, cognition and abilities to communicate effectively. Aldosterone is a mineralocorticoid hormone produced in the adrenal glands and plays a role in the maintenance of key ion pumps, including the Na-K+-Cl co-transporter 1 or NKCC1, w...
Source: Hearing Research - May 5, 2016 Category: Audiology Authors: Halonen J, Hinton A, Frisina RD, Ding B, Zhu X, Walton JP Tags: Hear Res Source Type: research
Frequency selectivity of the human cochlea: Suppression tuning of spontaneous otoacoustic emissions.
Abstract Frequency selectivity is a key functional property of the inner ear and since hearing research began, the frequency resolution of the human ear has been a central question. In contrast to animal studies, which permit invasive recording of neural activity, human studies must rely on indirect methods to determine hearing selectivity. Psychophysical studies, which used masking of a tone by other sounds, indicate a modest frequency selectivity in humans. By contrast, estimates using the phase delays of stimulus-frequency otoacoustic emissions (SFOAE) predict a remarkably high selectivity, unique among mammals...
Source: Hearing Research - April 29, 2016 Category: Audiology Authors: Manley GA, van Dijk P Tags: Hear Res Source Type: research
MEMRO 2015 - Basic Science meets Clinical Otology.
PMID: 27130517 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 26, 2016 Category: Audiology Authors: Gaihede M, Dirckx J, von Unge M, Rosowski JJ Tags: Hear Res Source Type: research
Cochlear implant and inflammation reaction: safety study of a new steroid-eluting electrode.
Abstract Dexamethasone is a common anti-inflammatory agent added to cochlear implants to reduce hearing loss due to electrode insertion trauma. We evaluated the safety of eluting silicone rods containing 10% dexamethasone in a Guinea pig model. Animals were implanted with a dexamethasone eluting silicone electrode (DER) or with a non-eluting electrode (NER). The control group only underwent a cochleostomy (CS). Prior to implantation and during the two weeks following implantation, the hearing status of the animals was assessed by means of Compound Action Potentials (CAPs) with an electrode placed near the round wi...
Source: Hearing Research - April 21, 2016 Category: Audiology Authors: Astolfi L, Simoni E, Giarbini N, Giordano P, Pannella M, Hatzopoulos S, Martini A Tags: Hear Res Source Type: research
Transmucosal Gas-Loss Rates in Middle Ears Initially Filled with O2 or CO2.
This study investigates the role of different gases in clearance of gas in the middle ear cavity (ME) by its mucosal blood flow. A rat model was used to measure gas volume changes in the ME cavity at constant pressure without ventilation. We disturbed the normal gas composition of the ME by filling it with O2 or CO2, measured the consequent changes in gas volume over time and compared these results with previously obtained ones for air and N2. The first 5 min of the primary transient phase (phase I) for O2 or CO2 was characterized by a volume loss decrease of -0.49 ± 0.34 μL and -46.28 ± 8.49 μL, respec...
Source: Hearing Research - April 19, 2016 Category: Audiology Authors: Kania RE, Verillaud B, Ars B, Ba Huy PT, Herman P, Ar A Tags: Hear Res Source Type: research