Low-frequency bias tone suppression of auditory-nerve responses to low-level clicks and tones.
Abstract We used low-frequency "bias" tones (BT's) to explore whether click and tone responses are affected in the same way by cochlear active processes. In nonlinear systems the responses to clicks are not always simply related to the responses to tones. Cochlear amplifier gain depends on the incremental slope of the outer-hair-cell (OHC) stereocilia mechano-electric transduction (MET) function. BTs transiently change the operating-point of OHC MET channels and can suppress cochlear-amplifier gain by pushing OHC METs into low-slope saturation regions. BT effects on single auditory-nerve (AN) fibers have...
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Nam H, Guinan JJ Tags: Hear Res Source Type: research

Endothelin-1 mediated induction of extracellular matrix genes in strial marginal cells underlies strial pathology in Alport mice.
Abstract Alport syndrome, a type IV collagen disorder, manifests as glomerular disease associated with hearing loss with thickening of the glomerular and strial capillary basement membranes (SCBMs). We have identified a role for endothelin-1 (ET-1) activation of endothelin A receptors (ETARs) in glomerular pathogenesis. Here we explore whether ET-1 plays a role in strial pathology. Wild type (WT) and Alport mice were treated with the ETAR antagonist, sitaxentan. The stria vascularis was analyzed for SCBM thickness and for extracellular matrix (ECM) proteins. Additional WT and Alport mice were exposed to noise or h...
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Meehan DT, Delimont D, Dufek B, Zallocchi M, Phillips G, Gratton MA, Cosgrove D Tags: Hear Res Source Type: research

The contribution of inferior colliculus activity to the auditory brainstem response (ABR) in mice.
In conclusion, the slow ABR wave P0 in the scalp ABR may represent a complementary non-invasive marker for IC activity in the mouse. Further, the latency of synchronized click-evoked activity in the IC supports the view that IC contributes to ABR wave V, and possibly also to ABR wave IV. PMID: 27562195 [PubMed - in process] (Source: Hearing Research)
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Land R, Burghard A, Kral A Tags: Hear Res Source Type: research

The effects of aging and sex on detection of ultrasonic vocalizations by adult CBA/CaJ mice (Mus musculus).
In conclusion, the results highlight the importance of studying complex signals across the lifespan. PMID: 27579993 [PubMed - in process] (Source: Hearing Research)
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Kobrina A, Dent ML Tags: Hear Res Source Type: research

Modelling the effect of round window stiffness on residual hearing after cochlear implantation.
Abstract Preservation of residual hearing after cochlear implantation is now considered an important goal of surgery. However, studies indicate an average post-operative hearing loss of around 20 dB at low frequencies. One factor which may contribute to post-operative hearing loss, but which has received little attention in the literature to date, is the increased stiffness of the round window, due to the physical presence of the cochlear implant, and to its subsequent thickening or to bone growth around it. A finite element model was used to estimate that there is approximately a 100-fold increase in th...
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Elliott SJ, Ni G, Verschuur CA Tags: Hear Res Source Type: research

A tri-coil bellows-type round window transducer with improved frequency characteristics for middle-ear implants.
In this study, a new tri-coil bellows-type transducer (TCBT), which has excellent low frequency output and is easy to implant, is proposed. To design the frequency characteristics of the TCBT, mechanical and electrical simulations were performed, and then a comparative analysis was conducted between a floating mass type transducer (like the FMT) and a fixed type transducer (like the TCBT). The features of the proposed TCBT are as follows. First, the TCBT's housing is fixed to the RW niche so that it does not vibrate. Second, the internal end of a tiny bellows is connected to a vibrating three-pole permanent magnet located ...
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Shin DH, Seong KW, Puria S, Lee KY, Cho JH Tags: Hear Res Source Type: research

A fast, stochastic, and adaptive model of auditory nerve responses to cochlear implant stimulation.
In this study, a computationally efficient model that accurately predicts auditory nerve responses to CI pulse train input was developed. A three-dimensional volume conduction and active nerve model developed at Leiden University Medical Center was extended with stochasticity, adaptation, and accommodation. This complete model includes spatial and temporal characteristics of both the cochlea and the auditory nerve. The model was validated by comparison with experimentally measured single fiber action potential responses to pulse trains published in the literature. The effects of pulse rate and pulse amplitude on spiking pa...
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: van Gendt MJ, Briaire JJ, Kalkman RK, Frijns JH Tags: Hear Res Source Type: research

Speech perception adjusts to stable spectrotemporal properties of the  listening environment.
Speech perception adjusts to stable spectrotemporal properties of the listening environment. Hear Res. 2016 Nov;341:168-178 Authors: Stilp CE, Anderson PW, Assgari AA, Ellis GM, Zahorik P Abstract When perceiving speech, listeners compensate for reverberation and stable spectral peaks in the speech signal. Despite natural listening conditions usually adding both reverberation and spectral coloration, these processes have only been studied separately. Reverberation smears spectral peaks across time, which is predicted to increase listeners' compensation for these peaks. This prediction was tested ...
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Stilp CE, Anderson PW, Assgari AA, Ellis GM, Zahorik P Tags: Hear Res Source Type: research

The effect of distraction on change detection in crowded acoustic scenes.
Abstract In this series of behavioural experiments we investigated the effect of distraction on the maintenance of acoustic scene information in short-term memory. Stimuli are artificial acoustic 'scenes' composed of several (up to twelve) concurrent tone-pip streams ('sources'). A gap (1000 ms) is inserted partway through the 'scene'; Changes in the form of an appearance of a new source or disappearance of an existing source, occur after the gap in 50% of the trials. Listeners were instructed to monitor the unfolding 'soundscapes' for these events. Distraction was measured by presenting distractor stimuli du...
Source: Hearing Research - October 31, 2016 Category: Audiology Authors: Petsas T, Harrison J, Kashino M, Furukawa S, Chait M Tags: Hear Res Source Type: research

Effects of long-term non-traumatic noise exposure on the adult central auditory system. Hearing problems without hearing loss.
Abstract It is known that hearing loss induces plastic changes in the brain, causing loudness recruitment and hyperacusis, increased spontaneous firing rates and neural synchrony, reorganizations of the cortical tonotopic maps, and tinnitus. Much less in known about the central effects of exposure to sounds that cause a temporary hearing loss, affect the ribbon synapses in the inner hair cells, and cause a loss of high-threshold auditory nerve fibers. In contrast there is a wealth of information about central effects of long-duration sound exposures at levels ≤ 80 dB SPL that do not even cause a temporary heari...
Source: Hearing Research - October 24, 2016 Category: Audiology Authors: Eggermont JJ Tags: Hear Res Source Type: research

Electro-acoustic pitch matching experiments in patients with single-sided deafness and a cochlear implant: Is there a need for adjustment of the default frequency allocation tables?
Abstract Patients with single-sided deafness (SSD) and a cochlear implant (CI) can compare the pitch of stimulated electrodes and acoustic tones. A pitch mismatch may negatively bear on the fusion of the signals from the two ears, which may limit auditory performance. We aimed to explore this mismatch, correlate it to performance, and finally to discuss its possible clinical consequences. Ten patients with SSD and a CI (Cochlear Ltd.) compared the pitch of electrical and acoustic stimuli. Patients had to choose one of two acoustic stimuli, with the pitch closest to the pitch of the electrical stimulus at electrode...
Source: Hearing Research - October 23, 2016 Category: Audiology Authors: Peters JP, Bennink E, Grolman W, van Zanten GA Tags: Hear Res Source Type: research

Long-term noise exposures: A brief review.
PMID: 27780746 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - October 21, 2016 Category: Audiology Authors: Davis R Tags: Hear Res Source Type: research

Effects of brain-derived neurotrophic factor (BDNF) on the cochlear nucleus in cats deafened as neonates.
PMID: 27773647 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - October 19, 2016 Category: Audiology Authors: Kandathil CK, Stakhovskaya O, Leake PA Tags: Hear Res Source Type: research

Editorial introduction: Special issue on plasticity following hearing loss and deafness.
PMID: 27771426 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - October 18, 2016 Category: Audiology Authors: Butler BE, Meredith MA, Lomber SG Tags: Hear Res Source Type: research

Performance in noise: Impact of reduced speech intelligibility on Sailor performance in a Navy command and control environment.
Abstract Noise, hearing loss, and electronic signal distortion, which are common problems in military environments, can impair speech intelligibility and thereby jeopardize mission success. The current study investigated the impact that impaired communication has on operational performance in a command and control environment by parametrically degrading speech intelligibility in a simulated shipborne Combat Information Center. Experienced U.S. Navy personnel served as the study participants and were required to monitor information from multiple sources and respond appropriately to communications initiated by inves...
Source: Hearing Research - October 18, 2016 Category: Audiology Authors: Keller MD, Ziriax JM, Barns W, Sheffield B, Brungart D, Thomas T, Jaeger B, Yankaskas K Tags: Hear Res Source Type: research

The influence of memory and attention on the ear advantage in dichotic listening.
Abstract The role of memory retention and attentional control on hemispheric asymmetry was investigated using a verbal dichotic listening paradigm, with the consonant-vowel syllables (/ba/,/da/,/ga/,/ka/,/pa/and/ta/), while manipulating the focus of attention and the time interval between stimulus and response. Attention was manipulated using three conditions: non-forced (NF), forced left (FL) and forced right (FR) attention. Memory involvement was varied using four delays (0, 1, 3 and 4 s) between stimulus presentation and response. Results showed a significant right ear advantage (REA) in the NF condition a...
Source: Hearing Research - October 18, 2016 Category: Audiology Authors: D'Anselmo A, Marzoli D, Brancucci A Tags: Hear Res Source Type: research

Category selectivity of the N170 and the role of expertise in deaf signers.
This study was designed to characterize the effects of early deafness and lifelong sign language use on visual category sensitivity of the N170 event-related potential. Images from nine categories of visual forms including upright faces, inverted faces, and hands were presented to twelve typically hearing adults and twelve adult congenitally deaf signers. Classic N170 category sensitivity was observed in both participant groups, whereby faces elicited larger amplitudes than all other visual categories, and inverted faces elicited larger amplitudes and slower latencies than upright faces. In hearing adults, hands elicited a...
Source: Hearing Research - October 18, 2016 Category: Audiology Authors: Mitchell TV Tags: Hear Res Source Type: research

Musicians' edge: A comparison of auditory processing, cognitive abilities and statistical learning.
Abstract It has been hypothesized that musical expertise is associated with enhanced auditory processing and cognitive abilities. Recent research has examined the relationship between musicians' advantage and implicit statistical learning skills. In the present study, we assessed a variety of auditory processing skills, cognitive processing skills, and statistical learning (auditory and visual forms) in age-matched musicians (N = 17) and non-musicians (N = 18). Musicians had significantly better performance than non-musicians on frequency discrimination, and backward digit span. A key finding w...
Source: Hearing Research - October 18, 2016 Category: Audiology Authors: Mandikal Vasuki PR, Sharma M, Demuth K, Arciuli J Tags: Hear Res Source Type: research

Spatial and temporal disparity in signals and maskers affects signal detection in non-human primates.
Abstract Detection thresholds for auditory stimuli (signals) increase in the presence of maskers. Natural environments contain maskers/distractors that can have a wide range of spatiotemporal properties relative to the signal. While these parameters have been well explored psychophysically in humans, they have not been well explored in animal models, and their neuronal underpinnings are not well understood. As a precursor to the neuronal measurements, we report the effects of systematically varying the spatial and temporal relationship between signals and noise in macaque monkeys (Macaca mulatta and Macaca radiata...
Source: Hearing Research - October 18, 2016 Category: Audiology Authors: Rocchi F, Dylla ME, Bohlen PA, Ramachandran R Tags: Hear Res Source Type: research

Hearing testing in the U.S. Department of Defense: Potential impact on Veterans Affairs hearing loss disability awards.
Abstract Hearing loss is the second most common disability awarded by the U.S. Department of Veterans Affairs (VA) to former members of the U.S. uniformed services. Hearing readiness and conservation practices differ among the four largest uniformed military services (Air Force, Army, Marine Corps, and Navy). Utilizing a data set consisting of all hearing loss claims submitted to the VA from fiscal years 2003-2013, we examined characteristics of veterans submitting claims within one year of separation from military service. Our results indicate that having a hearing loss disability claim granted was significantly ...
Source: Hearing Research - October 17, 2016 Category: Audiology Authors: Nelson JT, Swan AA, Swiger B, Packer M, Pugh MJ Tags: Hear Res Source Type: research

Developmental hearing loss impedes auditory task learning and performance in gerbils.
Abstract The consequences of developmental hearing loss have been reported to include both sensory and cognitive deficits. To investigate these issues in a non-human model, auditory learning and asymptotic psychometric performance were compared between normal hearing (NH) adult gerbils and those reared with conductive hearing loss (CHL). At postnatal day 10, before ear canal opening, gerbil pups underwent bilateral malleus removal to induce a permanent CHL. Both CHL and control animals were trained to approach a water spout upon presentation of a target (Go stimuli), and withhold for foils (Nogo stimuli). To asses...
Source: Hearing Research - October 12, 2016 Category: Audiology Authors: von Trapp G, Aloni I, Young S, Semple MN, Sanes DH Tags: Hear Res Source Type: research

Early age noise exposure increases loudness perception - A novel animal model of hyperacusis.
Abstract The neural mechanisms that give rise to hyperacusis, a reduction in loudness tolerance, are largely unknown. Some reports suggest that hyperacusis is linked to childhood hearing loss. However, the evidence for this is largely circumstantial. In order to rigorously test this hypothesis, we studied loudness changes in rats caused by intense noise exposure (12 kHz narrow band noise, 115 dB SPL, 4 h) at postnatal 16 days. Rats without noise exposure were used as controls. The exposed noise group (n = 7) showed a mean 40-50 dB hearing loss compared to the control group (n =&n...
Source: Hearing Research - October 12, 2016 Category: Audiology Authors: Alkharabsheh A, Xiong F, Manohar S, Chen G, Salvi R, Sun W Tags: Hear Res Source Type: research

Effects of noise on speech recognition: Challenges for communication by service members.
This article provides readers with an overview of the challenges associated with speech communication in noisy backgrounds, as well as its assessment and potential impact on functional performance, and provides guidance for important new research directions relevant not only to military personnel, but also to employees who work in high noise environments. PMID: 27743882 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - October 11, 2016 Category: Audiology Authors: Le Prell CG, Clavier O Tags: Hear Res Source Type: research

Perilymph pharmacokinetics of locally-applied gentamicin in the guinea pig.
In this study, gentamicin was applied to the round window niche as a 20 μL bolus of 40 mg/ml solution. Ten 2 μL samples of perilymph were collected sequentially from the lateral semi-circular canal (LSCC) at times from 1 to 4 h after application. Gentamicin concentration was typically highest in samples originating from the vestibule and was lower in samples originating from scala tympani. To interpret these results, perilymph elimination kinetics for gentamicin was quantified by loading the entire perilymph space by injection at the LSCC with a 500 μg/ml gentamicin solution followed by se...
Source: Hearing Research - October 7, 2016 Category: Audiology Authors: Salt AN, Hartsock JJ, Gill RM, King E, Kraus FB, Plontke SK Tags: Hear Res Source Type: research

Top-down and bottom-up neurodynamic evidence in patients with tinnitus.
Abstract Although a peripheral auditory (bottom-up) deficit is an essential prerequisite for the generation of tinnitus, central cognitive (top-down) impairment has also been shown to be an inherent neuropathological mechanism. Using an auditory oddball paradigm (for top-down analyses) and a passive listening paradigm (for bottom-up analyses) while recording electroencephalograms (EEGs), we investigated whether top-down or bottom-up components were more critical in the neuropathology of tinnitus, independent of peripheral hearing loss. We observed significantly reduced P300 amplitudes (reflecting fundamental cogni...
Source: Hearing Research - October 7, 2016 Category: Audiology Authors: Hong SK, Park S, Ahn MH, Min BK Tags: Hear Res Source Type: research

Quercetin protects against hair cell loss in the zebrafish lateral line and guinea pig cochlea.
Abstract Eighteen supplement drugs were screened using hair cells to determine a protective effect against the adverse effects of neomycin by using the zebrafish lateral line. The zebrafish were administered the supplement drugs 1 h before neomycin exposure. One hour later, animals were fixed in paraformaldehyde. Dose-response curves were generated to evaluate the protective effect on hair cells. The screen identified 3 supplements (quercetin, catechin and tannic acid). Three minutes after exposure to neomycin, increased antioxidant activity was found in the lateral line hair cells, as determined by the analy...
Source: Hearing Research - October 3, 2016 Category: Audiology Authors: Hirose Y, Sugahara K, Kanagawa E, Takemoto Y, Hashimoto M, Yamashita H Tags: Hear Res Source Type: research

Acute high-intensity noise induces rapid Arc protein expression but fails to rapidly change GAD expression in amygdala and hippocampus of rats: Effects of treatment with D-cycloserine.
Abstract Tinnitus is a devastating auditory disorder impacting a growing number of people each year. The aims of the current experiment were to assess neuronal mechanisms involved in the initial plasticity after traumatic noise exposure that could contribute to the emergence of tinnitus and to test a potential pharmacological treatment to alter this early neural plasticity. Specifically, this study addressed rapid effects of acute noise trauma on amygdalo-hippocampal circuitry, characterizing biomarkers of both excitation and inhibition in these limbic regions, and compared them to expression of these same markers...
Source: Hearing Research - September 30, 2016 Category: Audiology Authors: Kapolowicz MR, Thompson LT Tags: Hear Res Source Type: research

The potential use of low-frequency tones to locate regions of outer hair cell loss.
In this study, we lowered the concentration of ouabain to 1 mM and determined the physiologic effects on outer hair cells using distortion-product otoacoustic emissions. As well as quantifying the effects of 1 mM ouabain on the auditory nerve and outer hair cells, we attempted to reduce the neural contribution to the CR by using near-infrasonic stimulus frequencies of 45 and 85 Hz, and hypothesized that these low-frequency stimuli would generate a cumulative amplitude function (CAF) that could reflect damage to hair cells in the apex more accurately than the 762 stimuli. One hour after application of 1 ...
Source: Hearing Research - September 23, 2016 Category: Audiology Authors: Kamerer A, Diaz FJ, Peppi M, Chertoff M Tags: Hear Res Source Type: research

Differential tinnitus-related neuroplastic alterations of cortical thickness and surface area.
Abstract Structural neuroimaging techniques have been used to identify cortical and subcortical regions constituting the neuroarchitecture of tinnitus. One recent investigation used voxel-based morphometry (VBM) to analyze a sample of tinnitus patients (TI, n=257) [1]. A negative relationship between individual distress and cortical volume (CV) in bilateral auditory regions was observed. However, CV has meanwhile been identified as a neuroanatomical measurement that confounds genetically distinct neuroanatomical traits, namely cortical thickness (CT) and cortical surface area (CSA). We performed a re-analysis of t...
Source: Hearing Research - September 22, 2016 Category: Audiology Authors: Meyer M, Neff P, Liem F, Kleinjung T, Weidt S, Langguth B, Schecklmann M Tags: Hear Res Source Type: research

Reorganization of neural systems mediating peripheral visual selective attention in the deaf: An optical imaging study.
We report data from severe to profoundly deaf adults and normal-hearing controls who performed the Useful Field of View task while cortical activity was recorded using the event-related optical signal. Behavioral performance, obtained in a separate session, showed that deaf subjects had lower thresholds (i.e., better performance) on the Useful Field of View task. The event-related optical data indicated greater activity for the deaf adults than for the normal-hearing controls during the task in the posterior portion of Brodmann area 22 in the right hemisphere. Furthermore, the behavioral thresholds correlated significantly...
Source: Hearing Research - September 22, 2016 Category: Audiology Authors: Seymour JL, Low KA, Maclin EL, Chiarelli AM, Mathewson KE, Fabiani M, Gratton G, Dye MW Tags: Hear Res Source Type: research

Circadian regulation of auditory function.
PMID: 27665709 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - September 21, 2016 Category: Audiology Authors: Basinou V, Park JS, Cederroth CR, Canlon B Tags: Hear Res Source Type: research

Study of tonotopic brain changes with functional MRI and FDG-PET in a patient with unilateral objective cochlear tinnitus.
The objective cochlear tinnitus was measured by Spontaneous Otoacoustic Emissions (SOAE) equipment (frequency 9689 Hz, intensity 57 dB SPL) and is clearly audible to anyone standing near the patient. Functional modifications in primary auditory areas and other brain regions were evaluated using 3T and 7T fMRI and FDG-PET. In the fMRI evaluations, a saturation of the auditory cortex at the tinnitus frequency was observed, but the global cortical tonotopic organization remained intact when compared to the results of fMRI of healthy subjects. The FDG-PET showed no evidence of an increase or decrease of activity in the auditor...
Source: Hearing Research - September 19, 2016 Category: Audiology Authors: Guinchard AC, Ghazaleh N, Saenz M, Fornari E, Prior JO, Maeder P, Adib S, Maire R Tags: Hear Res Source Type: research

Hearing sensitivity differs between zebrafish lines used in auditory research.
Abstract Zebrafish are increasingly used in auditory studies, in part due to the development of several transgenic lines that express hair cell-specific fluorescent proteins. However, it is largely unknown how transgene expression influences auditory phenotype. We previously observed reduced auditory sensitivity in adult Brn3c:mGFP transgenic zebrafish, which express membrane-bound green fluorescent protein (GFP) in sensory hair cells. Here, we examine the auditory sensitivity of zebrafish from multiple transgenic and background strains. We recorded auditory evoked potentials in adult animals and observed signific...
Source: Hearing Research - September 16, 2016 Category: Audiology Authors: Monroe JD, Manning DP, Uribe PM, Bhandiwad A, Sisneros JA, Smith ME, Coffin AB Tags: Hear Res Source Type: research

Higher-order auditory areas in congenital deafness: Top-down interactions and corticocortical decoupling.
Abstract The theory of predictive coding assumes that higher-order representations influence lower-order representations by generating predictions about sensory input. In congenital deafness, one identified dysfunction is a reduced activation of deep layers in the auditory cortex. Since these layers play a central role for processing top-down influences, congenital deafness might interfere with the integration of top-down and bottom-up information flow. Studies in humans suggest more deficits in higher-order than in primary cortical areas in congenital deafness. That opens up the question how well neurons in highe...
Source: Hearing Research - September 12, 2016 Category: Audiology Authors: Kral A, Yusuf PA, Land R Tags: Hear Res Source Type: research

Time course and frequency specificity of sub-cortical plasticity in adults following acute unilateral deprivation.
Abstract Auditory deprivation and stimulation can change the threshold of the acoustic reflex, but the mechanisms underlying these changes remain largely unknown. In order to elucidate the mechanism, we sought to characterize the time-course as well as the frequency specificity of changes in acoustic reflex thresholds (ARTs). In addition, we compared ipsilateral and contralateral measurements because the pattern of findings may shed light on the anatomical location of the change in neural gain. Twenty-four normal-hearing adults wore an earplug continuously in one ear for six days. We measured ipsilateral and contr...
Source: Hearing Research - September 9, 2016 Category: Audiology Authors: Brotherton H, Plack CJ, Schaette R, Munro KJ Tags: Hear Res Source Type: research

Dopaminergic projections of the subparafascicular thalamic nucleus to the auditory brainstem.
Abstract Neuromodulators can alter the response properties of sensory neurons, including those in the auditory system. Dopamine, which plays a major role in reward and movement, has been shown to alter neural responses in the auditory brainstem and midbrain. Recently we identified the subparafascicular thalamic nucleus (SPF), part of the A11 dopaminergic cell group, as the source of dopamine to the inferior colliculus (IC). The superior olivary complex (SOC) is also a likely target of dopaminergic projections from the SPF because it receives projections from the SPF and contains fibers and terminals immunoreactive...
Source: Hearing Research - September 9, 2016 Category: Audiology Authors: Nevue AA, Felix RA, Portfors CV Tags: Hear Res Source Type: research

Cross-modal Plasticity in Developmental and Age-Related Hearing Loss: Clinical Implications.
We describe developmental cross-modal re-organization in the context of congenital or pre-lingual deafness in childhood and in the context of adult-onset, age-related hearing loss, with a focus on how cross-modal plasticity relates to clinical outcomes. We provide both single-subject and group-level evidence of cross-modal re-organization by the visual and somatosensory systems in bilateral, congenital deafness, single-sided deafness, adults with early-stage, mild-moderate hearing loss, and individual adult and pediatric patients exhibit excellent and average speech perception with hearing aids and cochlear implants. We di...
Source: Hearing Research - September 5, 2016 Category: Audiology Authors: Glick H, Sharma A Tags: Hear Res Source Type: research

A tri-coil bellows-type round window transducer with improved frequency characteristics for middle-ear implants.
In this study, a new tri-coil bellows-type transducer (TCBT), which has excellent low frequency output and is easy to implant, is proposed. To design the frequency characteristics of the TCBT, mechanical and electrical simulations were performed, and then a comparative analysis was conducted between a floating mass type transducer (like the FMT) and a fixed type transducer (like the TCBT). The features of the proposed TCBT are as follows. First, the TCBT's housing is fixed to the RW niche so that it does not vibrate. Second, the internal end of a tiny bellows is connected to a vibrating three-pole permanent magnet located ...
Source: Hearing Research - September 1, 2016 Category: Audiology Authors: Shin DH, Seong KW, Puria S, Lee KY, Cho JH Tags: Hear Res Source Type: research

A fast, stochastic, and adaptive model of auditory nerve responses to cochlear implant stimulation.
In this study, a computationally efficient model that accurately predicts auditory nerve responses to CI pulse train input was developed. A three-dimensional volume conduction and active nerve model developed at Leiden University Medical Center was extended with stochasticity, adaptation, and accommodation. This complete model includes spatial and temporal characteristics of both the cochlea and the auditory nerve. The model was validated by comparison with experimentally measured single fiber action potential responses to pulse trains published in the literature. The effects of pulse rate and pulse amplitude on spiking pa...
Source: Hearing Research - September 1, 2016 Category: Audiology Authors: van Gendt MJ, Briaire JJ, Kalkman RK, Frijns JH Tags: Hear Res Source Type: research

Speech perception adjusts to stable spectrotemporal properties of the listening environment.
Abstract When perceiving speech, listeners compensate for reverberation and stable spectral peaks in the speech signal. Despite natural listening conditions usually adding both reverberation and spectral coloration, these processes have only been studied separately. Reverberation smears spectral peaks across time, which is predicted to increase listeners' compensation for these peaks. This prediction was tested using sentences presented with or without a simulated reverberant sound field. All sentences had a stable spectral peak (added by amplifying frequencies matching the second formant frequency [F2] in the tar...
Source: Hearing Research - September 1, 2016 Category: Audiology Authors: Stilp CE, Anderson PW, Assgari AA, Ellis GM, Zahorik P Tags: Hear Res Source Type: research

The effect of distraction on change detection in crowded acoustic scenes.
Abstract In this series of behavioural experiments we investigated the effect of distraction on the maintenance of acoustic scene information in short-term memory. Stimuli are artificial acoustic 'scenes' composed of several (up to twelve) concurrent tone-pip streams ('sources'). A gap (1000 ms) is inserted partway through the 'scene'; Changes in the form of an appearance of a new source or disappearance of an existing source, occur after the gap in 50% of the trials. Listeners were instructed to monitor the unfolding 'soundscapes' for these events. Distraction was measured by presenting distractor stimuli du...
Source: Hearing Research - September 1, 2016 Category: Audiology Authors: Petsas T, Harrison J, Kashino M, Furukawa S, Chait M Tags: Hear Res Source Type: research

Modelling the effect of round window stiffness on residual hearing after cochlear implantation.
Abstract Preservation of residual hearing after cochlear implantation is now considered an important goal of surgery. However, studies indicate an average post-operative hearing loss of around 20 dB at low frequencies. One factor which may contribute to post-operative hearing loss, but which has received little attention in the literature to date, is the increased stiffness of the round window, due to the physical presence of the cochlear implant, and to its subsequent thickening or to bone growth around it. A finite element model was used to estimate that there is approximately a 100-fold increase in the round wi...
Source: Hearing Research - August 28, 2016 Category: Audiology Authors: Elliott SJ, Ni G, Verschuur CA Tags: Hear Res Source Type: research

The effects of aging and sex on detection of ultrasonic vocalizations by adult CBA/CaJ mice (Mus musculus).
In conclusion, the results highlight the importance of studying complex signals across the lifespan. PMID: 27579993 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - August 26, 2016 Category: Audiology Authors: Kobrina A, Dent ML Tags: Hear Res Source Type: research

The contribution of inferior colliculus activity to the auditory brainstem response (ABR) in mice.
In conclusion, the slow ABR wave P0 in the scalp ABR may represent a complementary non-invasive marker for IC activity in the mouse. Further, the latency of synchronized click-evoked activity in the IC supports the view that IC contributes to ABR wave V, and possibly also to ABR wave IV. PMID: 27562195 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - August 21, 2016 Category: Audiology Authors: Land R, Burghard A, Kral A Tags: Hear Res Source Type: research

Auditory Thalamic Circuits and GABAA Receptor Function: Putative Mechanisms in Tinnitus Pathology.
Abstract Tinnitus is defined as a phantom sound (ringing in the ears), and can significantly reduce the quality of life for those who suffer its effects. Ten to fifteen percent of the general adult population report symptoms of tinnitus with 1-2% reporting that tinnitus negatively impacts their quality of life. Noise exposure is the most common cause of tinnitus and the military environment presents many challenging high-noise situations. Military noise levels can be so intense that standard hearing protection is not adequate. Recent studies suggest a role for inhibitory neurotransmitter dysfunction in response to...
Source: Hearing Research - August 19, 2016 Category: Audiology Authors: Caspary DM, Llano DA Tags: Hear Res Source Type: research

Endothelin-1 Mediated Induction of Extracellular Matrix Genes in Strial Marginal Cells Underlies Strial Pathology in Alport Mice.
Abstract Alport syndrome, a type IV collagen disorder, manifests as glomerular disease associated with hearing loss with thickening of the glomerular and strial capillary basement membranes (SCBMs). We have identified a role for endothelin-1 (ET-1) activation of endothelin A receptors (ETARs) in glomerular pathogenesis. Here we explore whether ET-1 plays a role in strial pathology. Wild type (WT) and Alport mice were treated with the ETAR antagonist, sitaxentan. The stria vascularis was analyzed for SCBM thickness and for extracellular matrix (ECM) proteins. Additional WT and Alport mice were exposed to noise or h...
Source: Hearing Research - August 19, 2016 Category: Audiology Authors: Meehan DT, Delimont D, Dufek B, Zallocchi M, Phillips G, Gratton MA, Cosgrove D Tags: Hear Res Source Type: research

Low-Frequency Bias Tone Suppression of Auditory-Nerve Responses to Low-Level Clicks and Tones.
Abstract We used low-frequency "bias" tones (BT's) to explore whether click and tone responses are affected in the same way by cochlear active processes. In nonlinear systems the responses to clicks are not always simply related to the responses to tones. Cochlear amplifier gain depends on the incremental slope of the outer-hair-cell (OHC) stereocilia mechano-electric transductance (MET) function. BTs transiently change the operating-point of OHC MET channels and can suppress cochlear-amplifier gain by pushing OHC METs into low-slope saturation regions. BT effects on single auditory-nerve (AN) fibers hav...
Source: Hearing Research - August 17, 2016 Category: Audiology Authors: Nam H, Guinan JJ Tags: Hear Res Source Type: research

Differences in synaptic and intrinsic properties result in topographic heterogeneity of temporal processing of neurons within the inferior colliculus.
Abstract The identification and characterization of organization principals is essential for the understanding of neural function of brain areas. The inferior colliculus (IC) represents a midbrain nexus involved in numerous aspects of auditory processing. Likewise, neurons throughout the IC are tuned to a diverse range of specific stimulus features. Yet beyond a topographic arrangement of the cochlea-inherited frequency tuning, the functional organization of the IC is not well understood. Particularly, a common principle that links the diverse tuning characteristics is unknown. Here we used in vitro patch cla...
Source: Hearing Research - August 16, 2016 Category: Audiology Authors: Yassin L, Pecka M, Kajopoulos J, Gleiss H, Li L, Leibold C, Felmy F Tags: Hear Res Source Type: research

Across-site patterns of electrically evoked compound action potential amplitude-growth functions in multichannel cochlear implant recipients and the effects of the interphase gap.
Abstract Electrically evoked compound action potential (ECAP) measures of peak amplitude, and amplitude-growth function (AGF) slope have been shown to reflect characteristics of cochlear health (primarily spiral ganglion density) in anesthetized cochlear-implanted guinea pigs. Likewise, the effect of increasing the interphase gap (IPG) in each of these measures also reflects SGN density in the implanted guinea pig. Based on these findings, we hypothesize that suprathreshold ECAP measures, and also how they change as the IPG is increased, have the potential to be clinically applicable in human subjects. However, fu...
Source: Hearing Research - August 9, 2016 Category: Audiology Authors: Schvartz-Leyzac KC, Pfingst BE Tags: Hear Res Source Type: research

Effects of sustained release dexamethasone hydrogels in hearing preservation cochlear implantation.
r C Abstract It has been shown that glucocorticoids reduce the hearing threshold shifts associated with cochlear implantation. Previous studies evaluated the administration of glucocorticoids immediately before surgery or the repeated pre- or perioperative systemic application of glucocorticoids. The aim of this study was to evaluate the effects of a sustained release dexamethasone hydrogel in hearing preservation cochlear implantation. To address this issue, a guinea pig model of cochlear implantation was used. 30 normal hearing pigmented guinea pigs were randomized into a group receiving a single dose of a dexam...
Source: Hearing Research - August 8, 2016 Category: Audiology Authors: Honeder C, Zhu C, Schöpper H, Gausterer JC, Walter M, Landegger LD, Saidov N, Riss D, Plasenzotti R, Gabor F, Arnoldner C Tags: Hear Res Source Type: research