Dynamic current steering with phantom electrode in cochlear implants.
This study tested the hypothesis that dynamic current steering of PE stimuli can be implemented by varying σ over time to encode spectral details in low frequencies. To determine the range of σ for current steering and the corresponding current levels, Experiment 1 tested CI users' loudness balance and pitch ranking of static PE stimuli with σ from 0 to 0.6 in steps of 0.2. It was found that the equal-loudness most comfortable level significantly increased with σ and can be modeled by a piecewise linear function of σ. Consistent with the previous findings, higher σ elicited either lower ...
Source: Hearing Research - March 14, 2020 Category: Audiology Authors: Luo X, Garrett C Tags: Hear Res Source Type: research

Mismatch-negativity (MMN) in animal models: Homology of human MMN?
Abstract Mismatch negativity (MMN) has long been considered to be one of the deviance-detecting neural characteristics. Animal models exhibit similar neural activities, called MMN-like responses; however, there has been considerable debate on whether MMN-like responses are homologous to MMN in humans. Herein, we reviewed several studies that compared the electrophysiological, pharmacological, and functional properties of MMN-like responses and adaptation-exhibiting middle-latency responses (MLRs) in animals with those in humans. Accumulating evidence suggests that there are clear differences between MMN-like respo...
Source: Hearing Research - March 6, 2020 Category: Audiology Authors: Shiramatsu TI, Takahashi H Tags: Hear Res Source Type: research

Further validation of a binaural model predicting speech intelligibility against envelope-modulated noises.
Abstract Collin and Lavandier [J. Acoust. Soc. Am. 134, 1146-1159 (2013)] proposed a binaural model predicting speech intelligibility against envelope-modulated noises, evaluated in 24 acoustic conditions, involving similar masker types. The aim of the present study was to test the model robustness modeling 80 additional conditions, and evaluate the influence of its parameters using an approach inspired by a variance-based sensitivity analysis. First, the data from four experiments from the literature and one specifically designed for the present study were used to evaluate the prediction performance of the model,...
Source: Hearing Research - March 6, 2020 Category: Audiology Authors: Vicente T, Lavandier M Tags: Hear Res Source Type: research

Fetal gene therapy and pharmacotherapy to treat congenital hearing loss and vestibular dysfunction.
Abstract Disabling hearing loss is expected to affect over 900 million people worldwide by 2050. The World Health Organization estimates that the annual economic impact of hearing loss globally is US$ 750 billion. The inability to hear may complicate effective interpersonal communication and negatively impact personal and professional relationships. Recent advances in the genetic diagnosis of inner ear disease have keenly focused attention on strategies to restore hearing and balance in individuals with defined gene mutations. Mouse models of human hearing loss serve as the primary approach to test gene therapies ...
Source: Hearing Research - March 5, 2020 Category: Audiology Authors: Hastings ML, Brigande JV Tags: Hear Res Source Type: research

Preclinical testing of AAV9-PHP.B for transgene expression in the non-human primate cochlea.
We describe a transmastoid surgical approach needed to access the RWM of this common primate model. We found that AAV9-PHP.B transduced nearly 100% of both IHCs and OHCs, from base to apex, at the higher doses (3.5 × 1011 and 7 × 1011 vector genomes). However, at lower doses there was a steep reduction in viral transduction. Thus, AAV9-PHP.B efficiently transduces the IHCs and OHCs of nonhuman primates, and should be considered as an AAV capsid for inner ear gene therapy in humans. PMID: 32145977 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 26, 2020 Category: Audiology Authors: Ivanchenko MV, Hanlon KS, Devine MK, Tenneson K, Emond F, Lafond JF, Kenna MA, Corey DP, Maguire CA Tags: Hear Res Source Type: research

Simultaneous rather than retrograde spiral ganglion cell degeneration following ototoxically induced hair cell loss in the guinea pig cochlea.
Abstract Severe damage to the organ of Corti leads to degeneration of the spiral ganglion cells (SGCs) which form the auditory nerve. This degeneration starts at the level of synaptic connection of the peripheral processes (PPs) of SGCs with the cochlear hair cells. It is generally thought that from this point SGC degeneration progresses in a retrograde fashion: PPs degenerate first, followed by the SGC soma with a delay of several weeks to many months. Evidence for this course of events, both in animals and in humans, is not unambiguous, while this knowledge is important since the presence or absence of the diffe...
Source: Hearing Research - February 24, 2020 Category: Audiology Authors: Ramekers D, Klis SFL, Versnel H Tags: Hear Res Source Type: research

Comparison of electrode impedance measures between a dexamethasone-eluting and standard Cochlear ™ Contour Advance® electrode in adult cochlear implant recipients.
CONCLUSION: While rates of adoption of different surgical approaches differed between the groups and this may have had a confounding effect, the results suggest that passive elution of dexamethasone from the investigational device was associated with a change in the intracochlear environment following surgical implantation of the electrode array, as evidenced by the lower electrode impedance measures. PMID: 32143111 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 18, 2020 Category: Audiology Authors: Briggs R, O 'Leary S, Birman C, Plant K, English R, Dawson P, Risi F, Gavrilis J, Needham K, Cowan R Tags: Hear Res Source Type: research

Extended high frequency hearing and speech perception implications in adults and children.
This article is a compilation of contributions that, together, make the case for an essential role of EHF in both normal hearing and auditory dysfunction. We start with the fundamentals of biological and acoustic determinism - humans have EHF hearing for a purpose, for example, the detection of prey, predators, and mates. EHF hearing may also provide a boost to speech perception in challenging conditions and its loss, conversely, might help explain difficulty with the same task. However, it could be that EHF are a marker for damage in the conventional frequency region that is more related to speech perception difficulties....
Source: Hearing Research - February 18, 2020 Category: Audiology Authors: Hunter LL, Monson BB, Moore DR, Dhar S, Wright BA, Munro KJ, Zadeh LM, Blankenship CM, Stiepan SM, Siegel JH Tags: Hear Res Source Type: research

c.753A > G genome editing of a Cdh23ahl allele delays age-related hearing loss and degeneration of cochlear hair cells in C57BL/6J mice.
c.753A>G genome editing of a Cdh23ahl allele delays age-related hearing loss and degeneration of cochlear hair cells in C57BL/6J mice. Hear Res. 2020 Feb 18;389:107926 Authors: Yasuda SP, Seki Y, Suzuki S, Ohshiba Y, Hou X, Matsuoka K, Wada K, Shitara H, Miyasaka Y, Kikkawa Y Abstract C57BL/6J mice have long been studied as a model of age-related hearing loss (ARHL). In C57BL/6J mice, ARHL begins in the high-frequency range at 3 months of age and spreads toward low frequencies by 10 months of age. We previously confirmed that c.753A>G genome editing of an ahl allele (c.753A) in the cadherin 23 g...
Source: Hearing Research - February 18, 2020 Category: Audiology Authors: Yasuda SP, Seki Y, Suzuki S, Ohshiba Y, Hou X, Matsuoka K, Wada K, Shitara H, Miyasaka Y, Kikkawa Y Tags: Hear Res Source Type: research

The release from refractoriness hypothesis of N1 of event-related potentials needs reassessment.
Abstract N1 of event-related potentials (ERPs) is augmented in amplitude in ∼50-150 ms by occasional changes (deviants) in the physical features of a sound repeated at intervals of from ∼400 ms to seconds (standard). The release-from-refractoriness hypothesis links the N1 augmentation to a deviant-feature-specific neural population that is fresh to fully respond as opposed to a standard-feature-specific neural population that is unresponsive due to its post-response refractoriness. The present work explored this hypothesis in the context of ERP studies, behavioral habituation studies and studies ...
Source: Hearing Research - February 18, 2020 Category: Audiology Authors: Ruusuvirta T Tags: Hear Res Source Type: research

Human medial olivocochlear reflex: Contralateral activation effect on low and high frequency cochlear response.
Abstract The role of the medial olivocochlear (MOC) reflex has been investigated by assessing changes of cochlear responses (CR) in humans. The CR consists of pre-neural and neural potentials originating from the inner ear, and at high signal levels is dominated by cochlear microphonic (CM). The CM originates from the outer hair cells, where the MOC fibers synapse, and there is little research about using it to investigate the MOC reflex in humans. The current study aimed to investigate the effect of contralateral activation of the MOC reflex on the CR in humans. The CR was recorded in female adults (n = ...
Source: Hearing Research - February 15, 2020 Category: Audiology Authors: Jamos AM, Kaf WA, Chertoff ME, Ferraro JA Tags: Hear Res Source Type: research

Corrigendum to "Phase-locking of irregular Guinea pig primary vestibular afferents to high frequency ( > 250 Hz) sound and vibration" [Hear. Res. 373 (2019) 59-70].
Corrigendum to "Phase-locking of irregular Guinea pig primary vestibular afferents to high frequency (>250 Hz) sound and vibration" [Hear. Res. 373 (2019) 59-70]. Hear Res. 2020 Feb 14;:107909 Authors: Curthoys IS, Burgess AM, Goonetilleke SC PMID: 32067800 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 14, 2020 Category: Audiology Authors: Curthoys IS, Burgess AM, Goonetilleke SC Tags: Hear Res Source Type: research

Dual and triple AAV delivery of large therapeutic gene sequences into the inner ear.
Abstract Adeno-associated virus (AAV)-mediated gene therapy has evolved from the bench to the bedside, and is now considered the therapy of choice for certain inherited diseases. AAVs are attractive vectors for several reasons: they are nonpathogenic, result in long-term transgene expression, have a low immunogenic profile, and the various AAV serotypes and variants display broad but distinct tropisms allowing the targeting of specific cell types. However, one of the greatest limitations of AAVs is the limited genome-packaging capacity of ∼4.7 kb. Given that numerous diseases are caused by mutations in ge...
Source: Hearing Research - February 10, 2020 Category: Audiology Authors: Akil O Tags: Hear Res Source Type: research

Functional magnetic resonance imaging of enhanced central auditory gain and electrophysiological correlates in a behavioral model of hyperacusis.
Abstract Hyperacusis is a debilitating hearing condition in which normal everyday sounds are perceived as exceedingly loud, annoying, aversive or even painful. The prevalence of hyperacusis approaches 10%, making it an important, but understudied medical condition. To noninvasively identify the neural correlates of hyperacusis in an animal model, we used sound-evoked functional magnetic resonance imaging (fMRI) to locate regions of abnormal activity in the central nervous system of rats with behavioral evidence of hyperacusis induced with an ototoxic drug (sodium salicylate, 250 mg/kg, i.p.). Reaction time-in...
Source: Hearing Research - February 6, 2020 Category: Audiology Authors: Wong E, Radziwon K, Chen GD, Liu X, Manno FA, Manno SH, Auerbach B, Wu EX, Salvi R, Lau C Tags: Hear Res Source Type: research

Lovastatin protects against cisplatin-induced hearing loss in mice.
Abstract Cisplatin is used to treat a variety of solid tumors in both children and adults. However, cisplatin has serious side-effects, some of which may permanently affect patients' quality of life following treatment, such as ototoxicity. There is currently no FDA-approved therapy for the prevention or treatment of cisplatin-induced hearing loss. Herein we examine the potential for statins to prevent cisplatin-induced ototoxicity. Statins, a class of drugs commonly used to prevent or manage hypercholesterolemia, have been of clinical utility for decades with dependable outcomes and reliable safety profiles in hu...
Source: Hearing Research - February 6, 2020 Category: Audiology Authors: K F, Kk S, A R, L W, Tg B, S E, Ll C Tags: Hear Res Source Type: research

Small fish, big prospects: using zebrafish to unravel the mechanisms of hereditary hearing loss.
Abstract Over the past decade, advancements in high-throughput sequencing have greatly enhanced our knowledge of the mutational signatures responsible for hereditary hearing loss. In its present state, the field has a largely uncensored view of protein coding changes in a growing number of genes that have been associated with hereditary hearing loss, and many more that have been proposed as candidate genes. Sequencing data can now be generated using methods that have become widespread and affordable. The greatest hurdles facing the field concern functional validation of uncharacterized genes and rapid application ...
Source: Hearing Research - February 6, 2020 Category: Audiology Authors: Vona B, Doll J, Hofrichter MAH, Haaf T, Varshney GK Tags: Hear Res Source Type: research

Post-natal development of the envelope following response to amplitude modulated sounds in the bat Phyllostomus discolor.
f U Abstract Bats use a large repertoire of calls for social communication, which are often characterized by temporal amplitude and frequency modulations. As bats are considered to be among the few mammalian species capable of vocal learning, the perception of temporal sound modulations should be crucial for juvenile bats to develop social communication abilities. However, the post-natal development of auditory processing of temporal modulations has not been investigated in bats, so far. Here we use the minimally invasive technique of recording auditory brainstem responses to measure the envelope following respons...
Source: Hearing Research - January 30, 2020 Category: Audiology Authors: Hörpel SG, Firzlaff U Tags: Hear Res Source Type: research

Generation of a ChATCre mouse line without the early onset hearing loss typical of the C57BL/6J strain.
Abstract The development of knockin mice with Cre recombinase expressed under the control of the promoter for choline acetyltransferase (ChAT) has allowed experimental manipulation of cholinergic circuits. However, currently available ChATCre mouse lines are on the C57BL/6J strain background, which shows early onset age-related hearing loss attributed to the Cdh23753A mutation (a.k.a., the ahl mutation). To develop ChATCre mice without accelerated hearing loss, we backcrossed ChATIRES-Cre mice with CBA/CaJ mice that have normal hearing. We used genotyping to obtain mice homozygous for ChATIRES-Cre and the wild-typ...
Source: Hearing Research - January 20, 2020 Category: Audiology Authors: Beebe NL, Sowick CS, Kristaponyte I, Galazyuk AV, Vetter DE, Cox BC, Schofield BR Tags: Hear Res Source Type: research

Neural processes of auditory perception in Heschl's gyrus for upcoming acoustic stimuli in humans.
In this study, based on the direct intracerebral recordings from the auditory cortex in eight epileptic patients with refractory focal seizures, we investigated the neural processing of auditory attention by comparing the local field potentials before 'attentional' and 'distracted' conditions. Here we first showed a distinct build-up of slow, negative cortical potential in Heschl's gyrus. The amplitude increased steadily, starting from 600 to 800 ms before presentation of the tone until the onset of the evoked component P/N 60-80 when the patients were in the attentional condition. Because of their specific topographi...
Source: Hearing Research - January 18, 2020 Category: Audiology Authors: Hu M, Wang D, Ji X, Yu T, Shan Y, Fan X, Du J, Zhang X, Zhao G, Wang Y, Ren L, Liégeois-Chauvel C Tags: Hear Res Source Type: research

Efficient viral transduction in mouse inner ear hair cells with utricle injection and AAV9-PHP.B.
Abstract Viral delivery of exogenous coding sequences into the inner ear has the potential for therapeutic benefit for patients suffering genetic or acquired hearing loss. To devise improved strategies for viral delivery, we investigated two injection techniques, round window membrane injection or a novel utricle injection method, for their ability to safely and efficiently transduce sensory hair cells and neurons of the mouse inner ear. In addition, we evaluated three synthetic AAV vectors (Anc80L65, AAV9-PHP.B, AAV2.7m8) encoding enhanced green fluorescent protein (eGFP) and three promoters (Cmv, Synapsin, Gfap)...
Source: Hearing Research - January 13, 2020 Category: Audiology Authors: Lee J, Nist-Lund C, Solanes P, Goldberg H, Wu J, Pan B, Schneider BL, Holt JR Tags: Hear Res Source Type: research

Age-related changes in the number of cresyl-violet-stained, parvalbumin and NMDAR 2B expressing neurons in the human spiral ganglion.
Abstract Animal-studies associate age-related hearing loss (presbycusis) with decreasing number of spiral ganglion neurons (SGNs) in Rosenthal's canal (RC) of cochlea. The excitatory neurotransmitter for SGNs is glutamate (through its receptor NMDAR 2B), which can be neurotoxic through Ca2+ overload. Neurotoxicity is balanced by calcium-binding proteins (CBPs) like Parvalbumin (PV), which is the predominant CBP of the SGNs. To estimate the volume of the RC and total number of SGNs that are immunoreactive to PV and NMDAR 2B, we used unbiased stereology in 35 human cochleae derived from cadavers of persons from 2nd ...
Source: Hearing Research - January 8, 2020 Category: Audiology Authors: Kaur C, Saini S, Pal I, Kumar P, Chandra Sati H, Jacob TG, Bhardwaj DN, Roy TS Tags: Hear Res Source Type: research

Eardrum displacement and strain in the Tokay gecko (Gekko gecko) under quasi-static pressure loads.
x JJJ Abstract The eardrum is the primary component of the middle ear and has been extensively investigated in humans. Measuring the displacement and deformation of the eardrum under different quasi-static loading conditions gives insight in its mechanical behavior and is fundamental in determining the material properties of the eardrum. Currently, little is known about the behavior and material properties of eardrums in non-mammals. To explore the mechanical properties of the eardrum in non-mammalian ears, we investigated the quasi-static response of the eardrum of a common lizard: the Tokay gecko (Gekko gecko). ...
Source: Hearing Research - January 7, 2020 Category: Audiology Authors: Livens P, Gladiné K, Dirckx JJJ Tags: Hear Res Source Type: research

Bilateral bone conduction stimulation provides reliable binaural cues for localization.
This study aimed to characterize binaural hearing abilities with bone conduction stimulation in simulated conductive hearing loss. Bone conduction hearing devices (BCDs) are a common method of rehabilitating conductive hearing loss. However, little is known about the access these devices provide to binaural cues. To study the ability of BCDs to restore access to binaural cues in conductive loss, normal hearing listeners were plugged unilaterally and bilaterally and localization ability was assessed using a non-surgical BCD attached to the mastoid/s via an adhesive (MED-EL, Corp). The results demonstrate that 1) application...
Source: Hearing Research - January 3, 2020 Category: Audiology Authors: Snapp H, Vogt K, Agterberg MJH Tags: Hear Res Source Type: research

Novel oral multifunctional antioxidant prevents noise-induced hearing loss and hair cell loss.
Abstract Oxidative stress is a major contributor to noise-induced hearing loss, the most common cause of hearing loss among military personnel and young adults. HK-2 is a potent, orally-active, multifunctional, redox-modulating drug that has been shown to protect against a wide range of neurological disorders with no observed side effects. HK-2 protected cochlear HEI-OC1 cells against various forms of experimentally-induced oxidative stressors similar to those observed during and after intense noise exposure. The mechanisms by which HK-2 protects cells is twofold, first by its ability to reduce oxidative stress ge...
Source: Hearing Research - January 3, 2020 Category: Audiology Authors: Chen GD, Daszynski DM, Ding D, Jiang H, Woolman T, Blessing K, Kador PF, Salvi R Tags: Hear Res Source Type: research

Functional analysis of candidate genes from genome-wide association studies of hearing.
In this study, we asked if a set of 17 candidate genes highlighted by early GWAS reports of ARHL have detectable effects on hearing by knocking down expression levels of each gene in the mouse and analysing auditory function. We found two of the genes have an impact on hearing. Mutation of Dclk1 led to late-onset progressive increase in ABR thresholds and the A430005L14Rik (C1orf174) mutants showed worse recovery from noise-induced damage than controls. We did not detect any abnormal responses in the remaining 15 mutant lines either in thresholds or from our battery of suprathreshold ABR tests, and we discuss the possible ...
Source: Hearing Research - January 2, 2020 Category: Audiology Authors: Ingham NJ, Rook V, Di Domenico F, James E, Lewis MA, Girotto G, Buniello A, Steel KP Tags: Hear Res Source Type: research

Cisplatin-induced threshold shift in the CBA/CaJ, C57BL/6J, BALB/cJ mouse models of hearing loss.
This study was undertaken to model hearing loss at 16, 32, and 48 mg/kg cumulative doses of cisplatin in the CBA/CaJ, C57BL/6J, and BALB/cJ mouse strains. Mice were exposed to three cycles of 16 mg/kg cisplatin, for a cumulative dose of 48 mg/kg. Equal numbers of male and female mice were used in each strain, and the cisplatin was delivered in three different dosing schedules: a single bolus dose of 16 mg/kg followed by 20 days of recovery, 8 mg/kg doses delivered every ten days, and 4 mg/kg delivered daily for four consecutive days followed by 17 days of recovery. Auditory brainstem response ...
Source: Hearing Research - December 31, 2019 Category: Audiology Authors: DeBacker JR, Harrison RT, Bielefeld EC Tags: Hear Res Source Type: research

Evidence for gene-smoking interactions for hearing loss and deafness in Japanese American families.
CONCLUSIONS: To our knowledge this was the first report of possible gene-by-smoking interactions in HLD using family data. Additional work, including independent replication, is needed to understand the basis of these findings. HLD are important public health issues and understanding the contributions of genetic and environmental factors may inform public health messages and policies. PMID: 31896498 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - December 24, 2019 Category: Audiology Authors: Wan JY, Cataby C, Liem A, Jeffrey E, Norden-Krichmar TM, Goodman D, Santorico SA, Edwards KL, American Diabetes Association GENNID Study Group Tags: Hear Res Source Type: research

Differential cortical and subcortical projection targets of subfields in the core region of mouse auditory cortex.
Abstract The core region of the rodent auditory cortex has two areas: the primary auditory area (A1) and the anterior auditory field (AAF). However, the functional difference between these areas is unclear. To elucidate this issue, here we studied the projections from A1 and AAF in mice using adeno-associated virus (AAV) vectors expressing either a green fluorescent protein or a red fluorescent protein. After mapping A1 and AAF using optical imaging, we injected a distinct AAV vector into each of the two fields at a frequency-matched high-frequency location. We found that A1 and AAF projected commonly to virtually...
Source: Hearing Research - December 24, 2019 Category: Audiology Authors: Nakata S, Takemoto M, Song WJ Tags: Hear Res Source Type: research

P2RX2 and P2RX4 receptors mediate cation absorption in transitional cells and supporting cells of the utricular macula.
Abstract Purinergic receptors protect the cochlea during high-intensity stimulation by providing a parallel shunt pathway through non-sensory neighboring epithelial cells for cation absorption. So far, there is no direct functional evidence for the presence and type/subunit of purinergic receptors in the utricle of the vestibular labyrinth. The goal of the present study was to investigate which purinergic receptors are expressed and carry cation-absorption currents in the utricular transitional cells and macula. Purinergic agonists induced cation-absorption currents with a potency order of ATP > bzATP...
Source: Hearing Research - December 17, 2019 Category: Audiology Authors: Jeong J, Kim JY, Hong H, Wangemann P, Marcus DC, Jung J, Choi JY, Kim SH Tags: Hear Res Source Type: research

Intravenously delivered aminoglycoside antibiotics, tobramycin and amikacin, are not ototoxic in mice.
This study evaluated whether repeated i.v. administration of amikacin or tobramycin would induce hearing loss. Daily i.v. injections over a two-week period were well tolerated and transient low frequency hearing loss was observed in the aminoglycoside treatment groups. However, the hearing changes observed did not mimic the high frequency patterns of hearing loss observed in humans. Our results indicate that the i.v. delivery of tobramycin or amikacin is not an effective technique for inducing ototoxicity in mice. This result is consistent with previously published reports indicating that the mouse cochlea is resistant to ...
Source: Hearing Research - December 13, 2019 Category: Audiology Authors: Ogier JM, Lockhart PJ, Burt RA Tags: Hear Res Source Type: research

Associations between tinnitus and glaucoma suggest a common mechanism: A clinical and population-based study.
Abstract The purpose of this study was to determine if there is an association between tinnitus and glaucoma. We tested this by first completing a clinic-based cross-sectional questionnaire study in which we sent a series of tinnitus-related questions to glaucoma patients and healthy subjects, and then followed up with a large population-based cross-sectional study in which glaucoma and tinnitus were also assessed by questionnaire. For the clinical study, we received 209 responses from glaucoma patients and 109 responses from healthy subjects (primarily the spouses of the patients). For the population-based study,...
Source: Hearing Research - December 6, 2019 Category: Audiology Authors: Loiselle AR, Neustaeter A, de Kleine E, van Dijk P, Jansonius NM Tags: Hear Res Source Type: research

Dual-AAV delivery of large gene sequences to the inner ear.
Abstract Adeno-associated viruses (AAVs) are preferred vectors for gene replacement therapy, as they are non-pathogenic, non-inflammatory, induce stable transgene expression in terminally differentiated cells, and a series of natural and engineered capsid proteins can be employed to target the vectors to specific cells. Only one feature of AAVs is limiting: the low cargo capacity for foreign DNA, restricting their application to coding sequences of
Source: Hearing Research - November 28, 2019 Category: Audiology Authors: Reisinger E Tags: Hear Res Source Type: research

Novel insights into inner ear development and regeneration for targeted hearing loss therapies.
Abstract Sensorineural hearing loss is the most common sensory deficit in humans. Despite the global scale of the problem, only limited treatment options are available today. The mammalian inner ear is a highly specialized postmitotic organ, which lacks proliferative or regenerative capacity. Since the discovery of hair cell regeneration in non-mammalian species however, much attention has been placed on identifying possible strategies to reactivate similar responses in humans. The development of successful regenerative approaches for hearing loss strongly depends on a detailed understanding of the mechanisms that...
Source: Hearing Research - November 28, 2019 Category: Audiology Authors: Roccio M, Senn P, Heller S Tags: Hear Res Source Type: research

Gene therapy for genetic mutations affecting non-sensory cells in the cochlea.
Abstract Congenital hearing loss (HL) affects about 1 in every 500 infants. Among those affected more than half are caused by genetic mutations. According to the cellular sites affected by mutations in the cochlea, deafness genes could be classified into three major groups: those affecting the function of hair cells and synapses, cochlear supporting cells, and cells in the stria vascularis (SV) as well as in the lateral wall. The second and third groups account for more than half of all sensorineural hearing loss (SNHL) cases caused by genetic mutations. Current major treatment options for SNHL patients are hearin...
Source: Hearing Research - November 25, 2019 Category: Audiology Authors: Zhang L, Wu X, Lin X Tags: Hear Res Source Type: research

Contribution of spectral pinna cues for sound localization in children with congenital unilateral conductive hearing loss after hearing rehabilitation.
In conclusion, an important reason for the limited benefit of BCD fitting in children with congenital UCHL might be ascribed to an effective coping strategy (use of spectral pinna cues) that still plays a dominant role after BCD fitting. PMID: 31786443 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - November 17, 2019 Category: Audiology Authors: Vogt K, Wasmann JW, Van Opstal AJ, Snik AFM, Agterberg MJH Tags: Hear Res Source Type: research

Nanomechanical mapping reveals localized stiffening of the basilar membrane after cochlear implantation.
In conclusion, stiffening of the BM after cochlear implantation occurs over time, even at sites far apical to a cochlear implant. PMID: 31786442 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - November 16, 2019 Category: Audiology Authors: Choong JK, Hampson AJ, Brody KM, Lo J, Bester CW, Gummer AW, Reynolds NP, O'Leary SJ Tags: Hear Res Source Type: research

Paired measurements of cochlear function and hair cell count in Dutch-belted rabbits with noise-induced hearing loss.
Abstract The effects of noise-induced hearing loss have yet to be studied for the Dutch-belted strain of rabbits, which is the only strain that has been used in studies of the central auditory system. We measured auditory brainstem responses (ABRs), 2f1-f2 distortion product otoacoustic emissions (DPOAEs), and counts of cochlear inner and outer hair cells (IHCs and OHCs, respectively) from confocal images of Myo7a-stained cochlear whole-mounts in unexposed and noise-overexposed, Dutch-belted, male and female rabbits in order to characterize cochlear function and structure under normal-hearing and hearing-loss cond...
Source: Hearing Research - November 15, 2019 Category: Audiology Authors: Haragopal H, Dorkoski R, Johnson HM, Berryman MA, Tanda S, Day ML Tags: Hear Res Source Type: research

Modeling the characteristics of spontaneous otoacoustic emissions in lizards.
PMID: 31760263 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - November 15, 2019 Category: Audiology Authors: Wit HP, Manley GA, van Dijk P Tags: Hear Res Source Type: research

Neuronal sensitivity to the interaural time difference of the sound envelope in the mouse inferior colliculus.
We examined the sensitivity of the neurons in the mouse inferior colliculus (IC) to the interaural time differences (ITD) conveyed in the sound envelope. Utilizing optogenetic methods, we compared the responses to the ITD in the envelope of identified glutamatergic and GABAergic neurons. More than half of both cell types were sensitive to the envelope ITD, and the ITD curves were aligned at their troughs. Within the physiological ITD range of mice (±50 μs), the ITD curves of both cell types had a higher firing rate when the contralateral envelope preceded the ipsilateral envelope. These results show that the circ...
Source: Hearing Research - November 15, 2019 Category: Audiology Authors: Ono M, Bishop DC, Oliver DL Tags: Hear Res Source Type: research

Atoh1 is required in supporting cells for regeneration of vestibular hair cells in adult mice.
Abstract In amniotes, head movements are encoded by two types of vestibular hair cells (type I and type II) with unique morphology, physiology, and innervation. After hair cell destruction in mature rodents, supporting cells regenerate some type II hair cells, but no type I hair cells are replaced. The transcription factor Atoh1 is required for hair cell development, and Atoh1 is upregulated in supporting cells, the hair cell progenitors, in mature chickens and mice following hair cell damage. We investigated whether Atoh1 is required for type II hair cell regeneration in adult mice after genetic ablation of hair ...
Source: Hearing Research - November 7, 2019 Category: Audiology Authors: Hicks KL, Wisner SR, Cox BC, Stone JS Tags: Hear Res Source Type: research

Suppression tuning of spontaneous otoacoustic emissions in the barn owl (Tyto alba).
k P Abstract Spontaneous otoacoustic emissions (SOAEs) have been observed in a variety of different vertebrates, including humans and barn owls (Tyto alba). The underlying mechanisms producing the SOAEs and the meaning of their characteristics regarding the frequency selectivity of an individual and species are, however, still under debate. In the present study, we measured SOAE spectra in lightly anesthetized barn owls and suppressed their amplitudes by presenting pure tones at different frequencies and sound levels. Suppression effects were quantified by deriving suppression tuning curves (STCs) with a criterion...
Source: Hearing Research - November 1, 2019 Category: Audiology Authors: Engler S, Köppl C, Manley GA, de Kleine E, van Dijk P Tags: Hear Res Source Type: research

Association between shift work and hearing loss: The Dongfeng-Tongji cohort study.
Abstract The association between shift work and hearing loss is unclear. We aimed to evaluate this association in a Chinese population independently and in combination with occupational noise. A total of 11,196 participants of the Dongfeng-Tongji cohort study were included. Shift work was self-reported and hearing loss was defined as a pure-tone mean of 25 dB or higher at 0.5, 1, 2, and 4 kHz in any ear. The Robust Poisson method were used to assess the relationship between shift work and hearing loss, and the prevalence ratios (PRs) were calculated. Compared to individuals who reported no shift work, the PRs ...
Source: Hearing Research - October 26, 2019 Category: Audiology Authors: Wang D, Zhou Y, Ma J, Xiao L, Cao L, Zhou M, Kong W, Wang Z, Li W, He M, Zhang X, Guo H, Yuan J, Chen W Tags: Hear Res Source Type: research

Cortical thickness of left Heschl's gyrus correlates with hearing acuity in adults - A surface-based morphometry study.
r M Abstract To date, research examining the relationship between brain structure and hearing acuity is sparse, especially given the context of a broad age range. To investigate this relationship, we applied an automated surface-based morphometry (SBM) approach (FreeSurfer) in this study to re-examine a sample of normal-hearing (n = 17) and hearing-impaired (n = 17) age- and education-matched adults, aged between 20 and 63 years (Alfandari et al., 2018). The SBM approach allows the disentanglement of cortical surface area (CSA) from cortical thickness (CT), the 2 independent constituents of cortical v...
Source: Hearing Research - October 18, 2019 Category: Audiology Authors: Neuschwander P, Hänggi J, Zekveld AA, Meyer M Tags: Hear Res Source Type: research

Impact of stimulus frequency and recording electrode on electrocochleography in Hybrid cochlear implant users.
This report explores the impact of recording electrode position and stimulus frequency on intracochlear electrocochleography (ECoG) responses recorded from six Nucleus L24 Hybrid CI users. Acoustic tone bursts (250 Hz, 500 Hz, 750 Hz, and 1000 Hz) were presented to the implanted ear via an insert earphone. Recordings were obtained from intracochlear electrodes 6 (most basal), 8, 10, 12, 14, 16, 18, 20, and 22 (most apical). Responses to condensation and rarefaction stimuli were subtracted from one another to emphasize hair cell responses (CM/DIF) and added to one another to emphasize neural responses (ANN/SUM). For...
Source: Hearing Research - October 18, 2019 Category: Audiology Authors: Tejani VD, Carroll RL, Abbas PJ, Brown CJ Tags: Hear Res Source Type: research

Long-term effects and potential limits of intratympanic dexamethasone-loaded hydrogels combined with dexamethasone-eluting cochlear electrodes in a low-insertion  trauma Guinea pig model.
In this study we were able to show that use of a dexamethasone-eluting electrode alone and in combination with preoperative application of dexamethasone-loaded hydrogel significantly protects auditory nerve fibers. Furthermore, we have shown that a cochlear implantation-associated hearing threshold shift and tissue response may not be completely prevented by the sole application of dexamethasone. PMID: 31669876 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - October 17, 2019 Category: Audiology Authors: Ahmadi N, Gausterer JC, Honeder C, Mötz M, Schöpper H, Zhu C, Saidov N, Gabor F, Arnoldner C Tags: Hear Res Source Type: research

Modulatory influences on time-coding neurons in the ventral cochlear nucleus.
Abstract Bushy cells of the ventral cochlear nucleus are time-coding neurons. They receive axosomatic synaptic terminals from the auditory nerve, the so-called endbulb of Held synapses and project to sound localization centers in the superior olivary complex. Bushy cells are specialized to maintain and even improve the temporal code contained in the auditory nerve activity. In the present review an overview is given of the dynamic features and convergent inputs that modulate the response of bushy cells to auditory stimuli. The biophysics and synaptic specializations and dynamics of these neurons were studied exten...
Source: Hearing Research - October 17, 2019 Category: Audiology Authors: Kuenzel T Tags: Hear Res Source Type: research

Recovery from tympanic membrane perforation: Effects on membrane thickness, auditory thresholds, and middle ear transmission.
In this study, we measured TM thickness, auditory brainstem responses (ABR), and ME transmission immediately following a controlled pars tensa perforation and after 4 weeks of spontaneous recovery in a gerbil model. It is found that after recovery, the hearing thresholds showed a sloping pattern across frequencies: almost back to normal levels at frequencies between 2 and 8 kHz, sloping loss in the low (
Source: Hearing Research - October 15, 2019 Category: Audiology Authors: Cai L, Stomackin G, Perez NM, Lin X, Jung TT, Dong W Tags: Hear Res Source Type: research

Sequential stream segregation with bilateral cochlear implants.
Abstract Sequential stream segregation on the basis of binaural 'ear-of-entry', modulation rate and electrode place-of-stimulation cues was investigated in bilateral cochlear implant (CI) listeners using a rhythm anisochrony detection task. Sequences of alternating 'A' and 'B' bursts were presented via direct electrical stimulation and comprised either an isochronous timing structure or an anisochronous structure that was generated by delaying just the 'B' bursts. 'B' delay thresholds that enabled rhythm anisochrony detection were determined. Higher thresholds were assumed to indicate a greater likelihood of strea...
Source: Hearing Research - October 9, 2019 Category: Audiology Authors: Wijetillake AA, van Hoesel RJM, Cowan R Tags: Hear Res Source Type: research

Auditory streaming and bistability paradigm extended to a dynamic environment.
kin J Abstract We explore stream segregation with temporally modulated acoustic features using behavioral experiments and modelling. The auditory streaming paradigm in which alternating high- A and low-frequency tones B appear in a repeating ABA-pattern, has been shown to be perceptually bistable for extended presentations (order of minutes). For a fixed, repeating stimulus, perception spontaneously changes (switches) at random times, every 2-15 s, between an integrated interpretation with a galloping rhythm and segregated streams. Streaming in a natural auditory environment requires segregation of auditory obje...
Source: Hearing Research - October 5, 2019 Category: Audiology Authors: Byrne Á, Rinzel J, Rankin J Tags: Hear Res Source Type: research

Cortical auditory responses index the contributions of different RMS-level-dependent segments to speech intelligibility.
Abstract Previous behavioral and neurophysiological studies indicated that the use of an appropriate segmentation method to parse speech streams into meaningful chunks is of vital importance for the examination of sentence perception and intelligibility. Researchers have recently proposed speech segmentation methods employing the relative root-mean-square (RMS) intensity to separate sentences into segments with distinct intelligibility information. However, the effects of different RMS-level segments containing distinct intelligibility information on neural oscillations are not clear. Using scalp-recorded electroe...
Source: Hearing Research - October 4, 2019 Category: Audiology Authors: Wang L, Li H, Wu EX, Chen F Tags: Hear Res Source Type: research