Audibility, Speech perception and processing of temporal cues in ribbon synaptic disorders due to OTOF mutations.
Abstract Mutations in the OTOF gene encoding otoferlin result in a disrupted function of the ribbon synapses with an impaired multivesicular glutamate release. Most affected subjects present with congenital hearing loss and abnormal auditory brainstem potentials associated with preserved cochlear hair cell activities (otoacoustic emissions, cochlear microphonics [CMs]). Transtympanic electrocochleography (ECochG) has recently been proposed for defining the details of potentials arising in both the cochlea and auditory nerve in this disorder, and with a view to shedding light on the pathophysiological mechanisms un...
Source: Hearing Research - July 15, 2015 Category: Audiology Authors: Santarelli R, Del Castillo I, Cama E, Scimemi P, Starr A Tags: Hear Res Source Type: research

Vestibular function and temporal bone imaging in DFNB1.
Abstract DFNB1 is the most prevalent type of hereditary hearing impairment known nowadays and the audiometric phenotype is very heterogeneous. There is, however, no consensus in literature on vestibular and imaging characteristics. Vestibular function and imaging results of 44 DFNB1 patients were evaluated in this retrospective study. All patients displayed a response during rotational velocity step testing. In 65% of the cases, the caloric results were within normal range bilaterally. The video head impulse test was normal in all patients. In 34.4% of the CT scans one or more temporal bone anomalies were found. T...
Source: Hearing Research - July 15, 2015 Category: Audiology Authors: Oonk AM, Beynon AJ, Peters TA, Kunst HP, Admiraal RJ, Kremer H, Verbist B, Pennings RJ Tags: Hear Res Source Type: research

Reliable encoding and processing of auditory information is mediated by different types of synapses employing distinct molecular and structural mechanisms.
Abstract Hearing impairment is the most common human sensory deficit. Considering the sophisticated anatomy and physiology of the auditory system, disease-related failures frequently occur. To meet the demands of the neuronal circuits responsible for processing auditory information, the synapses of the lower auditory pathway are anatomically and functionally specialized to indefatigably process acoustic information with utmost temporal precision. However, while sharing some functional properties, the afferent synapses of the cochlea and of auditory brainstem differ greatly in their morphology and employ distinct m...
Source: Hearing Research - July 15, 2015 Category: Audiology Authors: Wichmann C Tags: Hear Res Source Type: research

Central auditory processing in patients with spinocerebellar ataxia.
CONCLUSIONS: A majority of patients exhibited SSW test deficits, with a predominance of bilateralism, and three-fourths had impaired RGDT performance, pointing to difficulties with binaural integration and temporal resolution. Assessment of CAPD is important for therapeutic follow ups in patients with SCA. PMID: 26183435 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 13, 2015 Category: Audiology Authors: Zeigelboim BS, de Carvalho HA, Teive HA, Liberalesso PB, Jurkiewicz AL, da Silva Abdulmassih EM, Marques JM, Cordeiro ML Tags: Hear Res Source Type: research

Proteomic identification of hair cell repair proteins in the model sea anemone Nematostella vectensis.
In this study, several polypeptides of RPs were isolated from mucus using blue native PAGE and then sequenced using LC-MS/MS. Thirty-seven known polypeptides were identified, including Hsp70s, as well as many polypeptide subunits of the 20S proteasome. Other identified polypeptides included those involved in cellular stress responses, protein folding, and protein degradation. Specific inhibitors of Hsp70s and the 20S proteasome were employed in experiments to test their involvement in hair bundle repair. The results of those experiments suggested that repair requires biologically active Hsp70s and 20S proteasomes. A model ...
Source: Hearing Research - July 13, 2015 Category: Audiology Authors: Tang PC, Watson GM Tags: Hear Res Source Type: research

Stream segregation in the anesthetized auditory cortex.
Abstract Auditory stream segregation describes the way that sounds are perceptually segregated into groups or streams on the basis of perceptual attributes such as pitch or spectral content. For sequences of pure tones, segregation depends on the tones' proximity in frequency and time. In the auditory cortex (and elsewhere) responses to sequences of tones are dependent on stimulus conditions in a similar way to the perception of these stimuli. However, although highly dependent on stimulus conditions, perception is also clearly influenced by factors unrelated to the stimulus, such as attention. Exactly how 'bottom...
Source: Hearing Research - July 9, 2015 Category: Audiology Authors: Scholes C, Palmer AR, Sumner CJ Tags: Hear Res Source Type: research

Subcortical processing in auditory communication.
z S Abstract The voice is a rich source of information, which the human brain has evolved to decode and interpret. Empirical observations have shown that the human auditory system is especially sensitive to the human voice, and that activity within the voice-sensitive regions of the primary and secondary auditory cortex is modulated by the emotional quality of the vocal signal, and may therefore subserve, with frontal regions, the cognitive ability to correctly identify the speaker's affective state. So far, the network involved in the processing of vocal affect has been mainly characterised at the cortical level....
Source: Hearing Research - July 8, 2015 Category: Audiology Authors: Pannese A, Grandjean D, Frühholz S Tags: Hear Res Source Type: research

Hyperinsulinemia/diabetes, hearing, and aging in the University of Wisconsin calorie restriction monkeys.
Abstract The purpose of this study was to determine the effects of hyperinsulinemia/Type 2 diabetes mellitus (HI-T2DM) on hearing impairment using rhesus monkeys to obtain control over diet and lifestyle factors that confound human studies. The study is a retrospective evaluation of rhesus monkeys from the Wisconsin National Primate Research Center (WNPRC) study on caloric restriction and aging. The research questions were the following: 1. Is HI-T2DM related to hearing impairment? 2. If so, what is the site of lesion in the auditory system? and 3. What physiological factors affect the risk of hearing loss in HI-T...
Source: Hearing Research - July 7, 2015 Category: Audiology Authors: Fowler CG, Chiasson KB, Colman R, Kemnitz JW, Beasley TM, Weindruch R Tags: Hear Res Source Type: research

Canertinib induces ototoxicity in three preclinical models.
In this study, a significant dose-dependent canertinib ototoxicity was observed in a zebrafish model. Canertinib ototoxicity was further confirmed in two mouse models with different genetic backgrounds. The data strongly suggested an evolutionally preserved ERBB molecular mechanism underlying canertinib ototoxicity. Thus, these results imply that clinical monitoring of hearing loss should be considered for clinical testing of canertinib or other pan-ERBB inhibitors. PMID: 26163095 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 7, 2015 Category: Audiology Authors: Tang J, Yi Q, Li H, Kopecky BJ, Ding D, Ou HC, DeCook R, Chen X, Sun Z, Kobel M, Bao J Tags: Hear Res Source Type: research

Auditory cortex directs the input-specific remodeling of thalamus.
Abstract Input-specific remodeling is observed both in the primary auditory cortex (AI) and the ventral division of the medial geniculate body of the thalamus (MGBv) through motivation such as learning. Here, we show the role of AI in the MGBv remodeling induced by the electrical stimulation (ES) of the central division of the inferior colliculus (ICc). For the MGBv neurons with frequency tunings different from those of electrically stimulated ICc neurons, their frequency tunings shifted towards the tunings of the ICc neurons. AI neurons also showed this input-specific remodeling after ES of the ICc (ESICc). Inter...
Source: Hearing Research - July 2, 2015 Category: Audiology Authors: Nelson S, Kong L, Liu X, Yan J Tags: Hear Res Source Type: research

Putative role of border cells in generating spontaneous morphological activity within Kölliker's organ.
Putative role of border cells in generating spontaneous morphological activity within Kölliker's organ. Hear Res. 2015 Jun 26; Authors: Nishani Dayaratne MW, Vlajkovic SM, Lipski J, Thorne PR Abstract Kölliker's organ is a transient epithelial structure, comprising a major part of the organ of Corti during pre-hearing stages of development. The auditory system is spontaneously active during development, which serves to retain and refine neural connections. Kölliker's organ is considered a key candidate for generating such spontaneous activity, most likely through purinergic (P2 receptor...
Source: Hearing Research - June 26, 2015 Category: Audiology Authors: Nishani Dayaratne MW, Vlajkovic SM, Lipski J, Thorne PR Tags: Hear Res Source Type: research

Restoration of middle-ear input in fluid-filled middle ears by controlled introduction of air or a novel air-filled implant.
In this study, air bubbles or air-filled implants were introduced into saline-filled human cadaveric MEs. Umbo velocity, a convenient measure of ME response, served as an indicator of hearing sensitivity. Filling the ME with saline reduced umbo velocity by 25-30 dB at low frequencies and more at high frequencies, consistent with earlier work (Ravicz et al., Hear. Res. 195: 103-130 (2004)). Small amounts of air (∼30 μl) in the otherwise saline-filled ME increased umbo velocity substantially, to levels only 10-15 dB lower than in the dry ME, in a frequency- and location-dependent manner: air in contact with the tympan...
Source: Hearing Research - June 26, 2015 Category: Audiology Authors: Ravicz ME, Chien WW, Rosowski JJ Tags: Hear Res Source Type: research

Decreased temporal precision of neuronal signaling as a candidate mechanism of auditory processing disorder.
Abstract The sense of hearing is the fastest of our senses and provides the first all-or-none action potential in the auditory nerve in less than four milliseconds. Short stimulus evoked latencies and their minimal variability are hallmarks of auditory processing from spiral ganglia to cortex. Here, we review how even small changes in first spike latencies (FSL) and their variability (jitter) impact auditory temporal processing. We discuss a number of mouse models with degraded FSL/jitter whose mutations occur exclusively in the central auditory system and therefore might serve as candidates to investigate the cel...
Source: Hearing Research - June 25, 2015 Category: Audiology Authors: Kopp-Scheinpflug C, Tempel BL Tags: Hear Res Source Type: research

Synaptic encoding and processing of auditory information in physiology and disease.
PMID: 26119179 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 25, 2015 Category: Audiology Authors: Moser T, Strenzke N Tags: Hear Res Source Type: research

The effect of visual cues on top-down restoration of temporally interrupted speech, with and without further degradations.
In this study we investigated if an accompanying video of the speaker can enhance the intelligibility of interrupted sentences, and the phonemic restoration benefit, measured by an increase in intelligibility when the silent intervals are filled with noise. Similar to previous studies, restoration benefit was observed with interrupted speech without spectral degradations (experiment 1), but was absent in acoustic simulations of CIs (experiment 2) and was present again in simulations of Electric Acoustic Stimulation (experiment 3). In all experiments, the additional speech information provided by the complementary visual cu...
Source: Hearing Research - June 24, 2015 Category: Audiology Authors: Benard MR, Başkent D Tags: Hear Res Source Type: research

The role of extended preoperative steroids in hearing preservation cochlear implantation.
Abstract INTRODUCTION: Steroids have been shown to reduce the hearing threshold shifts associated with cochlear implantation. Previous studies have examined only the administration of steroids just prior to surgery. The aim of this study is to examine the role of extended preoperative systemic steroids in hearing preservation cochlear implantation. METHODS: An animal model of cochlear implantation was used. 24 Hartley strain guinea pigs with a mean weight of 768 g and normal hearing were randomised into a control group, a second group receiving a single dose of systemic dexamethasone one day prior to surgery,...
Source: Hearing Research - June 24, 2015 Category: Audiology Authors: Kuthubutheen J, Coates H, Rowsell C, Nedzelski J, Chen JM, Lin V Tags: Hear Res Source Type: research

Theta, beta and gamma rate modulations in the developing auditory system.
ers J Abstract In the brain, the temporal analysis of many important auditory features relies on the synchronized firing of neurons to the auditory input rhythm. These so-called neural oscillations play a crucial role in sensory and cognitive processing and deviances in oscillatory activity have shown to be associated with neurodevelopmental disorders. Given the importance of neural auditory oscillations in normal and impaired sensory and cognitive functioning, there has been growing interest in their developmental trajectory from early childhood on. In the present study, neural auditory processing was investigate...
Source: Hearing Research - June 24, 2015 Category: Audiology Authors: Vanvooren S, Hofmann M, Poelmans H, Ghesquière P, Wouters J Tags: Hear Res Source Type: research

Auditory-neurophysiological responses to speech during early childhood: Effects of background noise.
Abstract Early childhood is a critical period of auditory learning, during which children are constantly mapping sounds to meaning. But learning rarely occurs under ideal listening conditions-children are forced to listen against a relentless din. This background noise degrades the neural coding of these critical sounds, in turn interfering with auditory learning. Despite the importance of robust and reliable auditory processing during early childhood, little is known about the neurophysiology underlying speech processing in children so young. To better understand the physiological constraints these adverse listen...
Source: Hearing Research - June 22, 2015 Category: Audiology Authors: White-Schwoch T, Davies EC, Thompson EC, Carr KW, Nicol T, Bradlow AR, Kraus N Tags: Hear Res Source Type: research

History of the tinnitus research consortium.
This article describes the creation and accomplishments of the Tinnitus Research Consortium (TRC), founded and supported through philanthropy and intended to enrich the field of tinnitus research. Bringing together a group of distinguished auditory researchers, most of whom were not involved in tinnitus research, over the fifteen years of its life it developed novel research approaches and recruited a number of new investigators into the field. The purpose of this special issue is to highlight some of the significant accomplishments of the investigators supported by the TRC. PMID: 26096056 [PubMed - as supplied by pub...
Source: Hearing Research - June 18, 2015 Category: Audiology Authors: Snow JB Tags: Hear Res Source Type: research

Morphological Correlates of Hearing Loss after Cochlear Implantation and Electro-Acoustic Stimulation in a Hearing-Impaired Guinea Pig Model.
The objective of this study was to determine the mechanisms of EAS-induced hearing loss in an animal model with high-frequency hearing loss. Guinea pigs were exposed to 24 hours of noise (12-24 kHz at 116 dB) to induce a high-frequency hearing loss. After recovery, two groups of animals were implanted (n=6 per group), with one group receiving chronic acoustic and electric stimulation for 10 weeks, and the other group receiving no stimulation during this time frame. A third group (n=6) was not implanted, but received chronic acoustic stimulation. Auditory brainstem responses were recorded biweekly to monitor changes in hear...
Source: Hearing Research - June 15, 2015 Category: Audiology Authors: Reiss LA, Stark G, Nguyen-Huynh AT, Spear KA, Zhang H, Tanaka C, Li H Tags: Hear Res Source Type: research

Integrated processing of spatial cues in human auditory cortex.
kki V Abstract Human sound source localization relies on acoustical cues, most importantly, the interaural differences in time and level (ITD and ILD). For reaching a unified representation of auditory space the auditory nervous system needs to combine the information provided by these two cues. In search for such a unified representation, we conducted a magnetoencephalography (MEG) experiment that took advantage of the location-specific adaptation of the auditory cortical N1 response. In general, the attenuation caused by a preceding adaptor sound to the response elicited by a probe depends on their spatial arran...
Source: Hearing Research - June 11, 2015 Category: Audiology Authors: Salminen NH, Takanen M, Santala O, Lamminsalo J, Altoè A, Pulkki V Tags: Hear Res Source Type: research

The effect of the resistive properties of bone on neural excitation and electric fields in cochlear implant models.
This study investigated the effect that bone resistivity has on modelled neural thresholds and intracochlear potentials using user-specific volume conduction models of implanted cochleae applying monopolar stimulation. The complexity of the description of the head volume enveloping the cochlea was varied between a simple infinite bone volume and a detailed skull containing a brain volume, scalp and accurate return electrode position. It was found that, depending on the structure of the head model and implementation of the return electrode, different bone resistivity values are necessary to match model predictions to data f...
Source: Hearing Research - June 11, 2015 Category: Audiology Authors: Malherbe TK, Hanekom T, Hanekom JJ Tags: Hear Res Source Type: research

Tinnitus Functional Index: Development, Validation, Outcomes Research, and Clinical Application.
Abstract The Tinnitus Research Consortium (TRC) issued a Request for Proposals in 2003 to develop a new tinnitus outcome measure that would: (1) be highly sensitive to treatment effects (validated for "responsiveness"); (2) address all major dimensions of tinnitus impact; and (3) be validated for scaling the negative impact of tinnitus. A grant was received by M. Meikle to conduct the study. In that observational study, all of the TRC objectives were met, with the final 25-item Tinnitus Functional Index (TFI) containing eight subscales. The study was published in 2012, and since then the TFI has received...
Source: Hearing Research - June 11, 2015 Category: Audiology Authors: Henry JA, Griest S, Thielman E, McMillan G, Kaelin C, Carlson KF Tags: Hear Res Source Type: research

Tinnitus: Maladaptive Auditory-Somatosensory Plasticity.
Abstract Tinnitus, the phantom perception of sound, is physiologically characterized by an increase in spontaneous neural activity in the central auditory system. However, as tinnitus is often associated with hearing impairment, it is unclear how a decrease of afferent drive can result in central hyperactivity. In this review, we first assess methods for tinnitus induction and objective measures of the tinnitus percept in animal models. From animal studies, we discuss evidence that tinnitus originates in the cochlear nucleus (CN), and hypothesize mechanisms whereby hyperactivity may develop in the CN after periphe...
Source: Hearing Research - June 11, 2015 Category: Audiology Authors: Wu C, Stefanescu RA, Martel DT, Shore SE Tags: Hear Res Source Type: research

Effects of Basilar Membrane Arch and Radial Tension on the Travelling Wave in Gerbil Cochlea.
Abstract The basilar membrane velocity of gerbil cochlea showed discrepancy between theoretical model and experimental measurements. We hypothesize that the reasons of such discrepancies are due to the arch towards the scala tympani and radial tension present in the basilar membrane of the gerbil cochlea. The arch changes the bending stiffness in the basilar membrane, reduces the effective fluid force on the membrane and increases the basilar membrane's inertia. The existence of the radial tension also dampens the acoustic travelling wave. In this paper, the wave number functions along the gerbil basilar membrane ...
Source: Hearing Research - June 9, 2015 Category: Audiology Authors: Chan WX, Yoon YJ Tags: Hear Res Source Type: research

Cortical Development and Neuroplasticity in Auditory Neuropathy Spectrum Disorder.
Abstract Cortical development is dependent to a large extent on stimulus-driven input. Auditory Neuropathy Spectrum Disorder (ANSD) is a recently described form of hearing impairment where neural dys-synchrony is the predominant characteristic. Children with ANSD provide a unique platform to examine the effects of asynchronous and degraded afferent stimulation on cortical auditory neuroplasticity and behavioral processing of sound. In this review, we describe patterns of auditory cortical maturation in children with ANSD. The disruption of cortical maturation that leads to these various patterns includes high leve...
Source: Hearing Research - June 9, 2015 Category: Audiology Authors: Sharma A, Cardon G Tags: Hear Res Source Type: research

The tip-link molecular complex of the auditory mechano-electrical transduction machinery.
Abstract Sound waves are converted into electrical signals by a process of mechano-electrical transduction (MET), which takes place in the hair bundle of cochlear hair cells. In response to the mechanical stimulus of the hair bundle, the tip-links, key components of the MET machinery, are tensioned and the MET channels open, which results in the generation of the cell receptor potential. Tip-links are composed of cadherin-23 (Cdh23) and protocadherin-15 (Pcdh15), both non-conventional cadherins, that form the upper and the lower part of these links, respectively. Here, we review the various Pcdh15 isoforms present...
Source: Hearing Research - June 3, 2015 Category: Audiology Authors: Pepermans E, Petit C Tags: Hear Res Source Type: research

Sound Localization in the Alligator.
Abstract In early tetrapods, it is assumed that the tympana were acoustically coupled through the pharynx and therefore inherently directional, acting as pressure difference receivers. The later closure of the middle ear cavity in turtles, archosaurs, and mammals is a derived condition, and would have changed the ear by decoupling the tympana. Isolation of the middle ears would then have led to selection for structural and neural strategies to compute sound source localization in both archosaurs and mammalian ancestors. In the archosaurs (birds and crocodilians) the presence of air spaces in the skull provided con...
Source: Hearing Research - June 2, 2015 Category: Audiology Authors: Bierman HS, Carr CE Tags: Hear Res Source Type: research

Vasopressin induces endolymphatic hydrops in mouse inner ear, as evaluated with repeated 9.4 T MRI.
In this study we evaluate the effect of vasopressin administration in vivo in longitudinal studies using two mouse strains. High resolution MRI at 9.4 T in combination with intraperitoneally delivered Gadolinium contrast, was performed before and after chronic subcutaneous administration of vasopressin via mini-osmotic pumps in the same mouse. A development of endolymphatic hydrops over time could be demonstrated in C57BL6 mice (5 mice, 2 and 4 weeks of administration) as well as in CBA/J mice (4 mice, 2 weeks of administration; 6 mice, 3 and 4 weeks of administration). In most C57BL6 mice hydrops developed first after mor...
Source: Hearing Research - June 2, 2015 Category: Audiology Authors: Degerman E, In 't Zandt R, Pålbrink A, Magnusson M Tags: Hear Res Source Type: research

Noninvasive scalp recording of cortical auditory evoked potentials in the alert macaque monkey.
Abstract Scalp-recorded evoked potentials (EP) provide researchers and clinicians with irreplaceable means for recording stimulus-related neural activities in the human brain, due to its high temporal resolution, handiness, and, perhaps more importantly, non-invasiveness. This work recorded the scalp cortical auditory EP (CAEP) in unanesthetized monkeys by using methods that are essentially identical to those applied to humans. Young adult rhesus monkeys (Macaca mulatta, 5-7 years old) were seated in a monkey chair, and their head movements were partially restricted by polystyrene blocks and tension poles placed a...
Source: Hearing Research - May 29, 2015 Category: Audiology Authors: Itoh K, Nejime M, Konoike N, Nakada T, Nakamura K Tags: Hear Res Source Type: research

Variation analysis of transcriptome changes reveals cochlear genes and their associated functions in cochlear susceptibility to acoustic overstimulation.
This study revealed that the constitutive expressions of cochlear genes displayed diverse levels of gene-specific variation. These variation patterns were altered by acoustic trauma; approximately one-third of the examined genes displayed marked increases in their expression variation. Bioinformatics analyses revealed that the genes that exhibited increased variation were functionally related to cell death, biomolecule metabolism, and membrane function. In contrast, the stable genes were primarily related to basic cellular processes, including protein and macromolecular syntheses and transport. There was no functional over...
Source: Hearing Research - May 26, 2015 Category: Audiology Authors: Yang S, Cai Q, Bard J, Jamison J, Wang J, Yang W, Hu BH Tags: Hear Res Source Type: research

Attenuation of hearing loss in DBA/2J mice by anti-apoptotic treatment.
Abstract DBA/2J mice are characterized by early onset hearing loss at about 3 to 4 weeks of age. Mutations in cadherin 23 (Cdh23) and fascin-2 (Fscn2) are responsible for the phenotypes, but the underlying mechanism is unknown. In the present study, DBA/2J mice displayed progressive hair cell loss and degeneration of spiral ganglion neurons (SGNs) after 2 weeks of age; however, the mRNA level of Caspase-3 in the inner ears was much higher at 2 weeks of age than that at 4 or 8 weeks of age. Moreover, transcriptional levels of Caspase-3 and Caspase-9 in the inner ears of DBA/2J mice were significantly higher than th...
Source: Hearing Research - May 20, 2015 Category: Audiology Authors: Yang L, Zhang H, Han X, Zhao X, Hu F, Li P, Xie G, Gao L, Cheng L, Song X, Han F Tags: Hear Res Source Type: research

Cochlear neuropathy in human presbycusis: confocal analysis of hidden hearing loss in post-mortem tissue.
Abstract Recent animal work has suggested that cochlear synapses are more vulnerable than hair cells in both noise-induced and age-related hearing loss. This synaptopathy is invisible in conventional histopathological analysis, because cochlear nerve cell bodies in the spiral ganglion survive for years, and synaptic analysis requires special immunostaining or serial-section electron microscopy. Here, we show that the same quadruple-immunostaining protocols that allow synaptic counts, hair cell counts, neuronal counts and differentiation of afferent and efferent fibers in mouse can be applied to human temporal bone...
Source: Hearing Research - May 19, 2015 Category: Audiology Authors: Viana LM, O'Malley JT, Burgess BJ, Jones DD, Oliveira CA, Santos F, Merchant SN, Liberman LD, Liberman MC Tags: Hear Res Source Type: research

Sensorineural hearing loss and ischemic injury: Development of animal models to assess vascular and oxidative effects.
Abstract Hearing loss may be genetic, associated with aging or exposure to noise or ototoxic substances. Its aetiology can be attributed to vascular injury, trauma, tumours, infections or autoimmune response. All these factors could be related to alterations in cochlear microcirculation resulting in hypoxia, which in turn may damage cochlear hair cells and neurons, leading to deafness. Hypoxia could underlie the aetiology of deafness, but very few data about it are presently available. The aim of this work is to develop animal models of hypoxia and ischemia suitable for study of cochlear vascular damage, character...
Source: Hearing Research - May 15, 2015 Category: Audiology Authors: Olivetto E, Simoni E, Guaran V, Astolfi L, Martini A Tags: Hear Res Source Type: research

Even in the era of congenital hypothyroidism screening mild and subclinical sensorineural hearing loss remains a relatively common complication of severe congenital hypothyroidism.
Abstract Only few studies have focused on neurosensory hearing function of patients with congenital hypothyroidism (CH) identified by CH screening programs and treated early and, therefore, this issue remains still controversial. The aim of this study was to ascertain whether an early and adequate replacement treatment may be able to prevent sensorineural hearing loss in 32 screened children with CH and no associated risk factors for neuro-otologic alterations. These patients were recruited according to highly selective criteria aiming to preliminarily exclude the negative interference of both treatment variables ...
Source: Hearing Research - May 15, 2015 Category: Audiology Authors: Bruno R, Aversa T, Catena M, Valenzise M, Lombardo F, De Luca F, Wasniewska M Tags: Hear Res Source Type: research

Effects of a dexamethasone-releasing implant on cochleae: a functional, morphological and pharmacokinetic study.
CONCLUSION: Cochlear implants that incorporate dexamethasone can release drug chronically in the inner ear and induce significant long-term recovery and preservation of auditory function after implantation. PMID: 25987502 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 15, 2015 Category: Audiology Authors: Liu Y, Jolly C, Braun S, Janssen T, Scherer E, Steinhoff J, Ebenhoch H, Lohner A, Stark T, Kiefer J Tags: Hear Res Source Type: research

Biology and Pathobiology of Lipid Droplets and their Potential Role in the Protection of the Organ of Corti.
We describe the role and mechanism by which LD play a role in human diseases, and we also review emerging data from our laboratory revealing the potential role of lipid droplets from Hensen cells in the auditory organ. We suggest that lipid droplets might help to develop rapidly and efficiently the resolution phase of inflammatory responses in the mammalian cochlea, preventing inflammatory damage of the delicate inner ear structures and, consequently, sensorineural hearing loss. PMID: 25987503 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 15, 2015 Category: Audiology Authors: Urrutia RA, Kalinec F Tags: Hear Res Source Type: research

The Application of Genome Editing in Studying Hearing Loss.
Abstract Targeted genome editing mediated by clustered, regularly interspaced, short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) technology has emerged as one of the most powerful tools to study gene functions, and with potential to treat genetic disorders. Hearing loss is one of the most common sensory disorders, affecting approximately 1 in 500 newborns with no treatment. Mutations of inner ear genes contribute to the largest portion of genetic deafness. The simplicity and robustness of CRISPR/Cas9-directed genome editing in human cells and model organisms such as zebrafish, mice and primates...
Source: Hearing Research - May 15, 2015 Category: Audiology Authors: Zou B, Mittal R, Grati M, Lu Z, Shu Y, Tao Y, Feng Y, Xie D, Kong W, Yang S, Chen ZY, Liu X Tags: Hear Res Source Type: research

Endolymphatic hydrops is prevalent in the first weeks following cochlear implantation.
CONCLUSIONS: EH is prevalent in the first weeks after implant surgery, even in the absence of significant electrode insertion trauma. PMID: 25987505 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 15, 2015 Category: Audiology Authors: Smeds AH, Eastwood HT, Hampson AJ, Sale P, Campbell LJ, Arhatari BD, Mansour S, O'Leary SJ Tags: Hear Res Source Type: research

Clinical trials supported by the Tinnitus Research Consortium: Lessons Learned, the Southern Illinois University Experience.
Abstract The Tinnitus Research Consortium funded three clinical trials investigating treatments for chronic bothersome tinnitus at Southern Illinois University School of Medicine. The trials were designed to measure the subjective changes in tinnitus distress using standardized questionnaires and objective changes in tinnitus loudness using psychophysical matching procedures. The results of the first two trials have been published and are summarized here. The first trial investigated the effect of gabapentin on the loudness and annoyance of tinnitus in adults with chronic bothersome tinnitus with and without a his...
Source: Hearing Research - May 13, 2015 Category: Audiology Authors: Bauer CA, Berry J, Brozoski TJ Tags: Hear Res Source Type: research

Item-nonspecific proactive interference in monkeys' auditory short-term memory.
Abstract Recent studies using the delayed matching-to-sample (DMS) paradigm indicate that monkeys' auditory short-term memory (STM) is susceptible to proactive interference (PI). During the task, subjects must indicate whether sample and test sounds separated by a retention interval are identical (match) or not (nonmatch). If a nonmatching test stimulus also occurred on a previous trial, monkeys are more likely to incorrectly make a "match" response (item-specific PI). However, it is not known whether PI may be caused by sounds presented on prior trials that are similar, but nonidentical to the current t...
Source: Hearing Research - May 13, 2015 Category: Audiology Authors: Bigelow J, Poremba A Tags: Hear Res Source Type: research

Cortical auditory evoked potentials as an objective measure of behavioral thresholds in cochlear implant users.
Abstract The aim of this study was to assess the suitability of using cortical auditory evoked potentials (CAEPs) as an objective tool for predicting behavioral hearing thresholds in cochlear implant (CI) users. Nine experienced adult CI users of Cochlear™ devices participated. Behavioral thresholds were measured in CI users across apical, mid and basal electrodes. CAEPs were measured for the same stimuli (50 ms pulse trains of 900-pps rate) at a range of input levels across the individual's psychophysical dynamic range (DR). Amplitude growth functions using global field power (GFP) were plotted, and from th...
Source: Hearing Research - May 7, 2015 Category: Audiology Authors: Visram AS, Innes-Brown H, El-Deredy W, McKay CM Tags: Hear Res Source Type: research

Simultaneous suppression of tone burst-evoked otoacoustic emissions: two and three-tone burst combinations.
Abstract Previous investigations have shown that components of a tone burst-evoked otoacoustic emission (TBOAE) evoked by a 1 kHz tone burst (TB1) can be suppressed by the simultaneous presence of a 2 kHz tone burst (TB2) or a pair of tone bursts at 2 and 3 kHz (TB2 and TB3 respectively). No previous study has measured this "simultaneous suppression of TBOAEs" for both TB2 alone and TB2 and TB3 from the same ears, so that the effect of the additional presence of TB3 on suppression caused by TB2 is not known. In simple terms, three outcomes are possible; suppression increases, suppression is reduced or su...
Source: Hearing Research - May 7, 2015 Category: Audiology Authors: Killan EC, Lutman ME, Thyer NJ Tags: Hear Res Source Type: research

Potassium Ion Channel Openers, Maxipost and Retigabine, Protect Against Peripheral Salicylate Ototoxicity in Rats.
Abstract Sodium Salicylate (SS) reliably induces a sensorineural hearing loss and tinnitus when administered in high doses. Recent animal modeled studies indicate that potassium channel openers such as Maxipost and Retigabine (RTG) can block SS- or noise-induced tinnitus respectively; however, the origins and mechanisms are poorly understood. Since SS blocks the same potassium channels that Maxipost and RTG open, we postulated that these drugs might influence peripheral auditory function. To test this hypothesis Maxipost or RTG were administered alone or in combination with SS in rats. When administered alone, Max...
Source: Hearing Research - April 30, 2015 Category: Audiology Authors: Sheppard AM, Chen GD, Salvi R Tags: Hear Res Source Type: research

Evidence for differential modulation of primary and nonprimary auditory cortex by forward masking in tinnitus.
Abstract It has been proposed that tinnitus is generated by aberrant neural activity that develops among neurons in tonotopic of regions of primary auditory cortex (A1) affected by hearing loss, which is also the frequency region where tinnitus percepts localize (Eggermont and Roberts 2004; Roberts et al., 2010, 2013). These models suggest (1) that differences between tinnitus and control groups of similar age and audiometric function should depend on whether A1 is probed in tinnitus frequency region (TFR) or below it, and (2) that brain responses evoked from A1 should track changes in the tinnitus percept when re...
Source: Hearing Research - April 30, 2015 Category: Audiology Authors: Roberts LE, Bosnyak DJ, Bruce IC, Gander PE, Paul BT Tags: Hear Res Source Type: research

No longer falling on deaf ears: mechanisms of degeneration and regeneration of cochlear ribbon synapses.
Abstract Cochlear ribbon synapses are required for the rapid and precise neural transmission of acoustic signals from inner hair cells to the spiral ganglion neurons. Emerging evidence suggests that damage to these synapses represents an important form of cochlear neuropathy that might be highly prevalent in sensorineural hearing loss. In this review, we discuss our current knowledge on how ribbon synapses are damaged by noise and during aging, as well as potential strategies to promote ribbon synapse regeneration for hearing restoration. PMID: 25937135 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 30, 2015 Category: Audiology Authors: Wan G, Corfas G Tags: Hear Res Source Type: research

Insulin-like growth factor 1: a novel treatment for the protection or regeneration of cochlear hair cells.
Abstract Sensorineural hearing loss (SNHL) is mainly caused by cochlear hair cell damage. Because cochlear hair cells and supporting cells lose their ability to proliferate in postnatal mammals, SNHL was thought to be an intractable disease. The maintenance of hair cell and supporting cell numbers after cochlear injury is therefore important for the treatment of sensorineural hearing loss. To achieve such treatment, protection and/or regeneration of hair cells is necessary. Progress in cochlear injury research, developmental biology, and regenerative medicine has led to the discovery of cochlear hair cells being p...
Source: Hearing Research - April 30, 2015 Category: Audiology Authors: Yamahara K, Yamamoto N, Nakagawa T, Ito J Tags: Hear Res Source Type: research

X-ray microtomographic confirmation of the reliability of CBCT in identifying the scalar location of cochlear implant electrode after round window insertion.
ykkö I PMID: 25922206 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 25, 2015 Category: Audiology Authors: Zou J, Hannula M, Lehto K, Feng H, Lähelmä J, Aula AS, Hyttinen J, Pyykkö I Tags: Hear Res Source Type: research

Correlative mRNA and Protein Expression of Middle and Inner Ear Inflammatory Cytokines during Mouse Acute Otitis Media.
Abstract Although the inner ear has long been reported to be susceptible to middle ear disease, little is known of the inflammatory mechanisms that might cause permanent sensorineural hearing loss. Recent studies have shown inner ear tissues are capable of expressing inflammatory cytokines during otitis media. However, little quantitative information is available concerning cytokine gene expression in the inner ear and the protein products that result. Therefore, this study was conducted of mouse middle and inner ear during acute otitis media to measure the relationship between inflammatory cytokine genes and thei...
Source: Hearing Research - April 25, 2015 Category: Audiology Authors: Trune DR, Kempton B, Hausman FA, Larrain BE, MacArthur CJ Tags: Hear Res Source Type: research

Effects of steep high-frequency hearing loss on speech recognition using temporal fine structure in low-frequency region.
Abstract The present study examined the effects of steep high-frequency sensorineural hearing loss (SHF-SNHL) on speech recognition using acoustic temporal fine structure (TFS) in the low-frequency region where the absolute thresholds appeared to be normal. In total, 28 participants with SHF-SNHL were assigned to 3 groups according to the cut-off frequency (1, 2, and 4 kHz, respectively) of their pure-tone absolute thresholds. Fourteen age-matched normal-hearing (NH) individuals were enrolled as controls. For each Mandarin sentence, the acoustic TFS in 10 frequency bands (each 3-ERB wide) was extracted using the H...
Source: Hearing Research - April 24, 2015 Category: Audiology Authors: Li B, Hou L, Xu L, Wang H, Yang G, Yin S, Feng Y Tags: Hear Res Source Type: research