Functions of CaBP1 and CaBP2 in the peripheral auditory system.
Lee A Abstract CaBPs are a family of Ca2+ binding proteins related to calmodulin. Two CaBP family members, CaBP1 and CaBP2, are highly expressed in the cochlea. Here, we investigated the significance of CaBP1 and CaBP2 for hearing in mice lacking expression of these proteins (CaBP1 KO and CaBP2 KO) using auditory brain responses (ABRs) and distortion product otoacoustic emissions (DPOAEs). In CaBP1 KO mice, ABR wave I was larger in amplitude, and shorter in latency and faster in decay, suggestive of enhanced synchrony of auditory nerve fibers. This interpretation was supported by the greater excitability of CaBP1 ...
Source: Hearing Research - April 9, 2018 Category: Audiology Authors: Yang T, Hu N, Pangršič T, Green S, Hansen M, Lee A Tags: Hear Res Source Type: research

A fluorescence-based imaging approach to pharmacokinetic analysis of intracochlear drug delivery.
Abstract Advances in microelectromechanical systems (MEMS) technologies are enhancing the development of intracochlear delivery devices for the treatment of hearing loss with emerging pharmacological therapies. Direct intracochlear delivery addresses the limitations of systemic and intratympanic delivery. However, optimization of delivery parameters for these devices requires pharmacokinetic assessment of the spatiotemporal drug distribution inside the cochlea. Robust methods of measuring drug concentration in the perilymph have been developed, but lack spatial resolution along the tonotopic axis or require comple...
Source: Hearing Research - April 5, 2018 Category: Audiology Authors: Ayoob AM, Peppi M, Tandon V, Langer R, Borenstein JT Tags: Hear Res Source Type: research

Hearing loss in older adults - From epidemiological insights to national initiatives.
Abstract The broader implications of hearing loss for the health and functioning of older adults have begun to be demonstrated in epidemiologic studies. These research findings on the association between hearing loss and poorer health outcomes have formed the foundation for national initiatives on hearing loss and public health. These national initiatives range from the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) clinical trial to the recent passage of the bipartisan Over-The-Counter Hearing Aid Act. Utilizing population health research methodologies to study hearing loss can provide the foundation f...
Source: Hearing Research - April 3, 2018 Category: Audiology Authors: Goman AM, Lin FR Tags: Hear Res Source Type: research

Vestibular and balance function is often impaired in children with profound unilateral sensorineural hearing loss.
CONCLUSIONS: The prevalence of vestibular dysfunction in children with unilateral deafness is high and similar to that of children with bilateral deafness. Vestibular and balance evaluation should be routine and the functional impact of combined vestibulo-cochlear sensory deficits considered. PMID: 29655975 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 3, 2018 Category: Audiology Authors: Sokolov M, Gordon KA, Polonenko M, Blaser SI, Papsin BC, Cushing SL Tags: Hear Res Source Type: research

Keeping track of sound objects in space: The contribution of early-stage auditory areas.
Abstract The influential dual-stream model of auditory processing stipulates that information pertaining to the meaning and to the position of a given sound object is processed in parallel along two distinct pathways, the ventral and dorsal auditory streams. Functional independence of the two processing pathways is well documented by conscious experience of patients with focal hemispheric lesions. On the other hand there is growing evidence that the meaning and the position of a sound are combined early in the processing pathway, possibly already at the level of early-stage auditory areas. Here, we investigated ho...
Source: Hearing Research - April 1, 2018 Category: Audiology Authors: Da Costa S, Clarke S, Crottaz-Herbette S Tags: Hear Res Source Type: research

Concurrent gradients of ribbon volume and AMPA-receptor patch volume in cochlear afferent synapses on gerbil inner hair cells.
l C Abstract The Mongolian gerbil is a classic animal model for age-related hearing loss. As a prerequisite for studying age-related changes, we characterized cochlear afferent synaptic morphology in young adult gerbils, using immunolabeling and quantitative analysis of confocal microscopic images. Cochlear wholemounts were triple-labeled with a hair-cell marker, a marker of presynaptic ribbons, and a marker of postsynaptic AMPA-type glutamate receptors. Seven cochlear positions covering an equivalent frequency range from 0.5 - 32 kHz were evaluated. The spatial positions of synapses were determined in a coordin...
Source: Hearing Research - April 1, 2018 Category: Audiology Authors: Zhang L, Engler S, Koepcke L, Steenken F, Köppl C Tags: Hear Res Source Type: research

Clinical trials for inner ear drugs: Design and execution challenges.
Abstract The development of therapies for the inner ear presents unique opportunities and challenges. On the one hand, the ear presents an opportunity for localized drug delivery to avoid systemic side effects. However, we do not understand the pathobiology of many common ear disorders clearly enough to develop rational therapeutic solutions. Further, identification of biomarkers beyond conventional audiometry and balance testing to track disease progress and recovery remain elusive. Because of the comparatively low incidence and prevalence of many inner ear disorders, as well as issues with respect to timing of d...
Source: Hearing Research - March 22, 2018 Category: Audiology Authors: Jung DH, Rauch SD Tags: Hear Res Source Type: research

Magnitude and phase of three-dimensional (3D) velocity vector: Application to measurement of cochlear promontory motion during bone conduction sound transmission.
Abstract Recent measurements of vibrational motion to assess sound transmission through ear structures and skull contents have included three-dimensional (3D) behavior. The 3D motion of a point has been described with the three orthogonal components in the 3D space. In this article, a method to represent the 3D velocity with the magnitude and phase of the resultant velocity is introduced. This method was applied to the measurement of cochlear promontory motion as an indication of bone conduction (BC) sound transmission. The promontory motions were measured on the ipsilateral and contralateral sides, and the transc...
Source: Hearing Research - March 21, 2018 Category: Audiology Authors: Dobrev I, Sim JH Tags: Hear Res Source Type: research

Effect of age and hearing loss on auditory stream segregation of speech sounds.
This study compared older HI listeners' performance with that of young and older normal-hearing (NH) listeners in stream segregation tasks involving speech sounds. Listeners were presented with sequences of speech tokens, each consisting of a fricative consonant and a voiced vowel (CV). The CV tokens were concatenated into interleaved sequences that alternated in fundamental frequency (F0) and/or simulated vocal tract length (VTL). Each pair of interleaved sequences was preceded by a "word" consisting of two random tokens. The listeners were asked to indicate whether the word was present in the following interlea...
Source: Hearing Research - March 21, 2018 Category: Audiology Authors: David M, Tausend AN, Strelcyk O, Oxenham AJ Tags: Hear Res Source Type: research

Hidden hearing loss and endbulbs of Held: Evidence for central pathology before detection of ABR threshold increases.
In this study of CBA/CaH mice, we provide evidence for age-related pathology in the endbulb of Held, a large axosomatic ending arising from myelinated auditory nerve fibers. Endbulbs are known to be involved in the processing of temporal cues used for sound localization and speech comprehension. Hearing thresholds as measured by auditory brainstem response (ABR) thresholds remained stable up to one year, whereas suprathreshold amplitudes of early ABR waves decreased by up to 50% in older mice, similar to that reported for age-related cochlear synaptopathy (Sergeyenko et al., 2013). The reduction of ABR response magnit...
Source: Hearing Research - March 20, 2018 Category: Audiology Authors: Muniak MA, Ayeni FE, Ryugo DK Tags: Hear Res Source Type: research

Auditory and audio-vocal responses of single neurons in the monkey ventral premotor cortex.
Abstract Monkey vocalization is a complex behavioral pattern, which is flexibly used in audio-vocal communication. A recently proposed dual neural network model suggests that cognitive control might be involved in this behavior, originating from a frontal cortical network in the prefrontal cortex and mediated via projections from the rostral portion of the ventral premotor cortex (PMvr) and motor cortex to the primary vocal motor network in the brainstem. For the rapid adjustment of vocal output to external acoustic events, strong interconnections between vocal motor and auditory sites are needed, which are presen...
Source: Hearing Research - March 20, 2018 Category: Audiology Authors: Hage SR Tags: Hear Res Source Type: research

Front- and rear-facing horizontal sound localization results in adults with unilateral hearing loss and normal hearing.
Abstract Binaural hearing allows listeners to take advantage of auditory cues that are necessary for sound localization. Patients with asymmetric or unilateral hearing loss receive degraded or absent binaural cues and often demonstrate decreased sound localization in the horizontal plane. Given the importance of sound localization for everyday function, there is a need for clinically feasible methods to evaluate localization, particularly as validation of intervention for patients with unilateral hearing loss. The present study compared sound localization results obtained for front-facing and rear-facing soundfiel...
Source: Hearing Research - March 19, 2018 Category: Audiology Authors: Nelson E, Reeder RM, Holden LK, Firszt JB Tags: Hear Res Source Type: research

Auditory and language outcomes in children with unilateral hearing loss.
CONCLUSIONS: Even when identified in the first months of life, children with UHL show a tendency to lag behind their normal hearing peers in functional auditory listening and in receptive and expressive language development. PMID: 29573881 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - March 13, 2018 Category: Audiology Authors: Fitzpatrick EM, Gaboury I, Durieux-Smith A, Coyle D, Whittingham J, Nassrallah F Tags: Hear Res Source Type: research

Paraquat initially damages cochlear support cells leading to anoikis-like hair cell death.
Abstract Paraquat (PQ), one of the most widely used herbicides, is extremely dangerous because it generates the highly toxic superoxide radical. When paraquat was applied to cochlear organotypic cultures, it not only damaged the outer hair cells (OHCs) and inner hair cells (IHCs), but also caused dislocation of the hair cell rows. We hypothesized that the dislocation arose from damage to the support cells (SCs) that anchors hair cells within the epithelium. To test this hypothesis, rat postnatal cochlear cultures were treated with PQ. Shortly after PQ treatment, the rows of OHCs separated from one another and migr...
Source: Hearing Research - March 13, 2018 Category: Audiology Authors: Zhang J, Sun H, Salvi R, Ding D Tags: Hear Res Source Type: research

Head shadow enhancement with low-frequency beamforming improves sound localization and speech perception for simulated bimodal listeners.
We present a new method to enhance head shadow in the low frequencies. Head shadow enhancement is achieved with a fixed beamformer with contralateral attenuation in each ear. The method results in interaural level differences which vary monotonically with angle. It also improves low-frequency signal-to-noise ratios in conditions with spatially separated speech and noise. We validated the method in two experiments with acoustic simulations of bimodal listening. In the localization experiment, performance improved from 50.5∘ to 26.8∘ root-mean-square error compared with standard omni-directional microphones. In the speec...
Source: Hearing Research - March 12, 2018 Category: Audiology Authors: Dieudonné B, Francart T Tags: Hear Res Source Type: research

Spontaneous otoacoustic emissions in teiid lizards.
Abstract SOAE from the last major lizard family not yet systematically investigated, the teiids, were collected from the genera Callopistes, Tupinambis and Cnemidophorus. Although their papillae show characteristics of the family Teiidae, the papillae differ both in their size and in the arrangement of uni- and bi-directional hair-cell areas. Among these three genera, Callopistes showed few (2 or 3) SOAE peaks, whereas the other two genera showed more (up to 6 per ear). In the absence of knowledge of the tonotopic maps, however, it was not possible to clearly relate the spectral patterns to the differences in papi...
Source: Hearing Research - March 12, 2018 Category: Audiology Authors: Manley GA, Wartini A, Schwabedissen G, Siegl E Tags: Hear Res Source Type: research

Auditory perceptual learning and changes in the conceptualization of auditory cortex.
Abstract Perceptual learning, improvement in discriminative ability as a consequence of training, is one of the forms of sensory system plasticity that has driven profound changes in our conceptualization of sensory cortical function. Psychophysical and neurophysiological studies of auditory perceptual learning have indicated that the characteristics of the learning, and by implication the nature of the underlying neural changes, are highly task specific. Some studies in animals have indicated that recruitment of neurons to the population responding to the training stimuli, and hence an increase in the so-called c...
Source: Hearing Research - March 12, 2018 Category: Audiology Authors: Irvine DRF Tags: Hear Res Source Type: research

Pharmacokinetic principles in the inner ear: Influence of drug properties on intratympanic applications.
Abstract Local drug delivery to the ear has gained wide clinical acceptance, with the choice of drug and application protocol in humans largely empirically-derived. Here, we review the pharmacokinetics underlying local therapy of the ear using the drugs commonly used in clinical practice as examples. Based on molecular properties and perilymph measurements interpreted through computer simulations we now better understand the principles underlying entry and distribution of these and other drugs in the ear. From our analysis, we have determined that dexamethasone-phosphate, a pro-drug widely-used clinically, has mol...
Source: Hearing Research - March 11, 2018 Category: Audiology Authors: Salt AN, Plontke SK Tags: Hear Res Source Type: research

Changing stimulation patterns can change the broadness of contralateral masking functions for bilateral cochlear implant users.
Abstract Past studies have found that contralateral masking functions are sharper than ipsilateral masking functions for cochlear implant (CI) users. This could suggest that contralateral masking effects are only sensitive to the peak of the masker stimulation for this population. To determine if that is the case, this study investigated whether using broader stimulation patterns affects the broadness of the contralateral masking function. Contralateral masking functions were measured for six bilateral CI users using both a broad and narrow masker. Findings from this study revealed that the broad masker resulted i...
Source: Hearing Research - March 7, 2018 Category: Audiology Authors: Lee DH, Aronoff JM Tags: Hear Res Source Type: research

Fetal auditory evoked responses to onset of amplitude modulated sounds. A fetal magnetoencephalography (fMEG) study.
Abstract The human fetal auditory system is functional around the 25th week of gestational age when the thalamocortical connections are established. Fetal magnetoencephalography (fMEG) provides evidence for fetal auditory brain responses to pure tones and syllables. Fifty-five pregnant women between 31 and 40 weeks of gestation were included in the study. Fetal MEG was recorded during the presentation of an amplitude modulated tone (AM) with a carrier frequency of 500 Hz to the maternal abdomen modulated by low modulation rates (MRs) - 2/s and 4/s, middle MR - 8/s and high MRs - 27/s, 42/s, 78/s and 91/s. The ai...
Source: Hearing Research - March 6, 2018 Category: Audiology Authors: Draganova R, Schollbach A, Schleger F, Braendle J, Brucker S, Abele H, Kagan KO, Wallwiener D, Fritsche A, Eswaran H, Preissl H Tags: Hear Res Source Type: research

Vowel and tone recognition in quiet and in noise among Mandarin-speaking amusics.
In this study, we examined vowel-plus-tone identification in quiet and noise conditions among Mandarin-speaking amusics with and without speech tone difficulties (tone agnosics and pure amusics, respectively), and IQ- and age-matched controls. Overall, pure amusics showed vowel and tone identification comparable to the controls in both quiet and noise conditions. Compared to pure amusics and controls, tone agnosics showed deficits in tone perception in both quiet and noise conditions. More importantly, their vowel perception was lower than pure amusics and controls in noise conditions, e.g., at a signal-to-noise ratio of&n...
Source: Hearing Research - March 6, 2018 Category: Audiology Authors: Tang W, Wang XJ, Li JQ, Liu C, Dong Q, Nan Y Tags: Hear Res Source Type: research

Special issue on computational models of hearing.
PMID: 29496112 [PubMed - in process] (Source: Hearing Research)
Source: Hearing Research - March 1, 2018 Category: Audiology Authors: Carney LH Tags: Hear Res Source Type: research

Simulated auditory nerve axon demyelination alters sensitivity and response timing to extracellular stimulation.
Abstract Since cochlear implant function involves direct depolarization of spiral ganglion neurons (SGNs) by applied current, SGN physiological health must be an important factor in cochlear implant (CI) outcomes. This expected relationship has, however, been difficult to confirm in implant recipients. Suggestively, animal studies have demonstrated both acute and progressive SGN ultrastructural changes (notably axon demyelination), even in the absence of soma death, and corresponding altered physiology following sensorineural deafening. Whether such demyelination occurs in humans and how such changes might impact ...
Source: Hearing Research - February 14, 2018 Category: Audiology Authors: Resnick JM, O'Brien GE, Rubinstein JT Tags: Hear Res Source Type: research

Persistent hair cell malfunction contributes to hidden hearing loss.
Abstract Noise exposures that result in fully reversible changes in cochlear neural threshold can cause a reduced neural output at supra-threshold sound intensity. This so-called "hidden hearing loss" has been shown to be associated with selective degeneration of high threshold afferent nerve fiber-inner hair cell (IHC) synapses. However, the electrophysiological function of the IHCs themselves in hidden hearing loss has not been directly investigated. We have made round window (RW) measurements of cochlear action potentials (CAP) and summating potentials (SP) after two levels of a 10 kHz acoustic trau...
Source: Hearing Research - February 14, 2018 Category: Audiology Authors: Mulders WHAM, Chin IL, Robertson D Tags: Hear Res Source Type: research

Acute blockade of inner ear marginal and dark cell K+ secretion: Effects on gravity receptor function.
Abstract Specific pharmacological blockade of KCNQ (Kv7) channels with XE991 rapidly (within 20 min) and profoundly alters inner ear gravity receptor responses to head motion (Lee et al., 2017). We hypothesized that these effects were attributable to the suppression of K+ secretion following blockade of KCNQ1-KCNE1 channels in vestibular dark cells and marginal cells. To test this hypothesis, K+ secretion was independently inhibited by blocking the Na+-K+-2Cl- cotransporter (NKCC1, Slc12a2) rather than KCNQ1-KCNE1 channels. Acute blockade of NKCC1 with ethacrynic acid (40 mg/kg) eliminated auditory respon...
Source: Hearing Research - February 13, 2018 Category: Audiology Authors: Lee C, Jones TA Tags: Hear Res Source Type: research

Effects of AUT00063, a Kv3.1 channel modulator, on noise-induced hyperactivity in the dorsal cochlear nucleus.
Abstract The purpose of this study was to test whether a Kv3 potassium channel modulator, AUT00063, has therapeutic potential for reversing noise-induced increases in spontaneous neural activity, a state that is widely believed to underlie noise-induced tinnitus. Recordings were conducted in noise exposed and control hamsters from dorsal cochlear nucleus (DCN) fusiform cells before and following intraperitoneal administration of AUT00063 (30 mg/kg). Fusiform cell spontaneous activity was increased in sound-exposed animals, approximating levels that were nearly 50% above those of controls. Administration of AUT00...
Source: Hearing Research - February 7, 2018 Category: Audiology Authors: Glait L, Fan W, Stillitano G, Sandridge S, Pilati N, Large C, Alvaro G, Kaltenbach JA Tags: Hear Res Source Type: research

Specialization of the auditory system for the processing of bio-sonar information in the frequency domain: Mustached bats.
Abstract For echolocation, mustached bats emit velocity-sensitive orientation sounds (pulses) containing a constant-frequency component consisting of four harmonics (CF1-4). They show unique behavior called Doppler-shift compensation for Doppler-shifted echoes and hunting behavior for frequency and amplitude modulated echoes from fluttering insects. Their peripheral auditory system is highly specialized for fine frequency analysis of CF2 (∼61.0 kHz) and detecting echo CF2 from fluttering insects. In their central auditory system, lateral inhibition occurring at multiple levels sharpens V-shaped frequency-tun...
Source: Hearing Research - February 2, 2018 Category: Audiology Authors: Suga N Tags: Hear Res Source Type: research

Suppression of the vestibular short-latency evoked potential by electrical stimulation of the central vestibular system.
Abstract In an attempt to view the effects of the efferent vestibular system (EVS) on peripheral dynamic vestibular function, we have monitored the Vestibular short-latency Evoked Potential (VsEP) evoked by pulses of bone conducted vibration during electrical stimulation of the EVS neurons near the floor of the fourth ventricle in the brainstem of anesthetized guinea pigs. Given the reported effects of EVS on primary afferent activity, we hypothesized that EVS stimulation would cause a slight reduction in the VsEP amplitude. Our results show a substantial (>50%) suppression of the VsEP, occurring immediately af...
Source: Hearing Research - February 2, 2018 Category: Audiology Authors: Pastras CJ, Curthoys IS, Sokolic L, Brown DJ Tags: Hear Res Source Type: research

Low- and high-frequency cortical brain oscillations reflect dissociable mechanisms of concurrent speech segregation in noise.
Abstract Parsing simultaneous speech requires listeners use pitch-guided segregation which can be affected by the signal-to-noise ratio (SNR) in the auditory scene. The interaction of these two cues may occur at multiple levels within the cortex. The aims of the current study were to assess the correspondence between oscillatory brain rhythms and determine how listeners exploit pitch and SNR cues to successfully segregate concurrent speech. We recorded electrical brain activity while participants heard double-vowel stimuli whose fundamental frequencies (F0s) differed by zero or four semitones (STs) presented in ei...
Source: Hearing Research - February 2, 2018 Category: Audiology Authors: Yellamsetty A, Bidelman GM Tags: Hear Res Source Type: research

The relation between flocculus volume and tinnitus after cerebellopontine angle tumor surgery.
CONCLUSIONS: The lack of a relation between flocculus volumes and the presence of tinnitus, combined with the significant correlation between tinnitus severity and flocculus volumes, suggests that the flocculus may not be the primary source of tinnitus, but is likely to mediate tinnitus severity. The reduced ipsi-to-contralateral volume ratio in patients with gaze-modulated tinnitus suggests that atrophy of the flocculus on the surgery side triggers cross-modal interactions leading to modulation of tinnitus. PMID: 29398141 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - January 31, 2018 Category: Audiology Authors: Mennink LM, Van Dijk JMC, Van Der Laan BFAM, Metzemaekers JDM, Van Laar PJ, Van Dijk P Tags: Hear Res Source Type: research

Unilateral congenital hearing loss in children: Challenges and potentials.
Abstract The estimated incidence of sensorineural hearing impairment (>40 dB HL) at birth is 1.86 per 1000 newborns in developed countries and 30-40% of these are unilateral. Profound sensorineural unilateral hearing impairment or single sided deafness (SSD) can be treated with a cochlear implant. However, this treatment is costly and invasive and unnecessary in the eyes of many. Very young children with SSD often do not exhibit language and cognitive delays and it is hard to imagine that neurocognitive skills will present difficulties with one good ear. In the current paper we review the most recent evidence...
Source: Hearing Research - January 30, 2018 Category: Audiology Authors: van Wieringen A, Boudewyns A, Sangen A, Wouters J, Desloovere C Tags: Hear Res Source Type: research

Subcortical pathways: Towards a better understanding of auditory disorders.
rs CV Abstract Hearing loss is a significant problem that affects at least 15% of the population. This percentage, however, is likely significantly higher because of a variety of auditory disorders that are not identifiable through traditional tests of peripheral hearing ability. In these disorders, individuals have difficulty understanding speech, particularly in noisy environments, even though the sounds are loud enough to hear. The underlying mechanisms leading to such deficits are not well understood. To enable the development of suitable treatments to alleviate or prevent such disorders, the affected processi...
Source: Hearing Research - January 26, 2018 Category: Audiology Authors: Felix RA, Gourévitch B, Portfors CV Tags: Hear Res Source Type: research

Transcriptomic analysis of chicken cochleae after gentamicin damage and the involvement of four signaling pathways (Notch, FGF, Wnt and BMP) in hair cell regeneration.
Abstract Unlike mammalian hair cells, which are essentially unable to regenerate after damage, avian hair cells have a robust capacity for regeneration. The prerequisite for understanding the above difference is knowing the genetic programming of avian hair cell regeneration. Although the major processes have been known, the precise molecular signaling that induces regeneration remains unclear. To address this issue, we performed a high-throughput transcriptomic analysis of gene expression during hair cell regeneration in the chick cochlea after antibiotic injury in vivo. A total of 16,588 genes were found to...
Source: Hearing Research - January 17, 2018 Category: Audiology Authors: Jiang L, Xu J, Jin R, Bai H, Zhang M, Yang S, Zhang X, Zhang X, Han Z, Zeng S Tags: Hear Res Source Type: research

Evidence of noise-induced subclinical hearing loss using auditory brainstem responses and objective measures of noise exposure in humans.
Abstract Exposure to loud sound places the auditory system at considerable risk, especially when the exposure is routine. The current study examined the impact of routine auditory overexposure in young human adults with clinically-normal audiometric thresholds by measuring the auditory brainstem response (ABR), an electrophysiological measure of peripheral and central auditory processing. Sound exposure was measured objectively with body-worn noise dosimeters over a week. Participants were divided into low-exposure and high-exposure groups, with the low-exposure group having an average daily noise exposure dose of...
Source: Hearing Research - January 11, 2018 Category: Audiology Authors: Skoe E, Tufts J Tags: Hear Res Source Type: research

Induction of mitophagy in the HEI-OC1 auditory cell line and activation of the Atg12/LC3 pathway in the organ of Corti.
Abstract Autophagy is a highly evolutionary conserved quality control defense mechanism within cells, which has also been implicated in cell death processes. In the mammalian inner ear, autophagy has been shown to play a role during early morphogenesis as well as in adult cochlear hair cells exposed to ototoxic insults. Mitophagy, a selective autophagic cell process targeting mitochondria, hasn't been studied in the inner ear so far. On this work, we searched for molecular indicators of mitophagy within House Ear Institute-Organ of Corti-1 (HEI-OC1) cells as well as in the organ of Corti (OC). We first tested for ...
Source: Hearing Research - January 11, 2018 Category: Audiology Authors: Setz C, Benischke AS, Pinho Ferreira Bento AC, Brand Y, Levano S, Paech F, Leitmeyer K, Bodmer D Tags: Hear Res Source Type: research

Neural representation of octave illusion in the human cortex revealed with functional magnetic resonance imaging.
This study aimed to explore the link between the perception of illusory pitches and brain activity during presentation of dichotic tones. We conducted a behavioral study of how participants perceived binaural dichotic tones of octave illusions and classified them, based on the reported percepts, in an illusion (ILL) group, without an illusion (non-ILL) group, and others. We recorded brain activity using functional magnetic resonance imaging and analyzed the activation due to dichotic illusion tones. The activation in the bilateral planum polare in the auditory cortex was significantly larger in the ILL group than in the no...
Source: Hearing Research - January 8, 2018 Category: Audiology Authors: Tanaka K, Kurasaki H, Kuriki S Tags: Hear Res Source Type: research

Incorporating behavioral and sensory context into spectro-temporal models of auditory encoding.
Abstract For several decades, auditory neuroscientists have used spectro-temporal encoding models to understand how neurons in the auditory system represent sound. Derived from early applications of systems identification tools to the auditory periphery, the spectro-temporal receptive field (STRF) and more sophisticated variants have emerged as an efficient means of characterizing representation throughout the auditory system. Most of these encoding models describe neurons as static sensory filters. However, auditory neural coding is not static. Sensory context, reflecting the acoustic environment, and behavioral ...
Source: Hearing Research - December 31, 2017 Category: Audiology Authors: David SV Tags: Hear Res Source Type: research

A biophysical modelling platform of the cochlear nucleus and other auditory circuits: From channels to networks.
Abstract Models of the auditory brainstem have been an invaluable tool for testing hypotheses about auditory information processing and for highlighting the most important gaps in the experimental literature. Due to the complexity of the auditory brainstem, and indeed most brain circuits, the dynamic behavior of the system may be difficult to predict without a detailed, biologically realistic computational model. Despite the sensitivity of models to their exact construction and parameters, most prior models of the cochlear nucleus have incorporated only a small subset of the known biological properties. This confo...
Source: Hearing Research - December 28, 2017 Category: Audiology Authors: Manis PB, Campagnola L Tags: Hear Res Source Type: research

Auditory sensory gating predicts acceptable noise level.
PMID: 29325873 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - December 28, 2017 Category: Audiology Authors: Miller SE, Wathen K, Cash E, Pitts T, Cornell L Tags: Hear Res Source Type: research

Perceptual changes with monopolar and phantom electrode stimulation.
This study investigates the perceptual differences (including pitch and other sound quality differences) at multiple electrode positions using MP and PE stimulation using both a multidimensional scaling procedure (MDS) and a traditional scaling procedure. 10 Advanced Bionics users reported the perceptual distances between 5 single electrode (typically 1, 3, 5, 7, and 9) stimuli in either MP or PE (σ = 0.5) mode. Subjects were asked to report how perceptually different each pair of stimuli were using any perceived differences except loudness. Subsequently, each stimulus was presented in isolation and subjects scal...
Source: Hearing Research - December 28, 2017 Category: Audiology Authors: Klawitter S, Landsberger DM, Büchner A, Nogueira W Tags: Hear Res Source Type: research

What can stimulus polarity and interphase gap tell us about auditory nerve function in cochlear-implant recipients?
Abstract Modeling studies suggest that differences in neural responses between polarities might reflect underlying neural health. Specifically, large differences in electrically evoked compound action potential (eCAP) amplitudes and amplitude-growth-function (AGF) slopes between polarities might reflect poorer peripheral neural health, whereas more similar eCAP responses between polarities might reflect better neural health. The interphase gap (IPG) has also been shown to relate to neural survival in animal studies. Specifically, healthy neurons exhibit larger eCAP amplitudes, lower thresholds, and steeper AGF slo...
Source: Hearing Research - December 28, 2017 Category: Audiology Authors: Hughes ML, Choi S, Glickman E Tags: Hear Res Source Type: research

Transauricular vagus nerve stimulation at auricular acupoints Kindey (CO10), Yidan (CO11), Liver (CO12) and Shenmen (TF4) can induce auditory and limbic cortices activation measured by fMRI.
In conclusion, taVNS at acupoints CO10-12, TF4 could activate the prefrontal, auditory and limbic cortices of healthy brain and this scheme could be a promising tool for tinnitus treatment. PMID: 29305037 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - December 24, 2017 Category: Audiology Authors: Peng L, Mu K, Liu A, Zhou L, Gao Y, Shenoy IT, Mei Z, Chen Q Tags: Hear Res Source Type: research

Intentional switching in auditory selective attention: Exploring attention shifts with different reverberation times.
Abstract Using a well-established binaural-listening paradigm the ability to intentionally switch auditory selective attention was examined under anechoic, low reverberation (0.8 s) and high reverberation (1.75 s) conditions. Twenty-three young, normal-hearing subjects were tested in a within-subject design to analyze influences of the reverberation times. Spoken word pairs by two speakers were presented simultaneously to subjects from two of eight azimuth positions. The stimuli consisted of a single number word, (i.e., 1 to 9), followed by either the direction "UP" or "DOWN" in German. Gui...
Source: Hearing Research - December 22, 2017 Category: Audiology Authors: Oberem J, Seibold J, Koch I, Fels J Tags: Hear Res Source Type: research

Negative-delay sources in distortion product otoacoustic emissions.
Abstract Long-delay components showing a symmetrical pattern with positive and negative delays can be observed in the time-frequency representation (or in the inverse Fourier transform) of distortion product otoacoustic emissions. Positive-only phase-gradient delays are predicted by place-fixed backscattering mechanisms, such as coherent reflection due to roughness, whereas the nonlinear distortion wave-fixed mechanism should generate an almost null-delay component. The symmetrical delay pattern arises whenever spectral amplitude fluctuations are not fully correlated to phase fluctuations. An interpretation of thi...
Source: Hearing Research - December 22, 2017 Category: Audiology Authors: Sisto R, Shera CA, Moleti A Tags: Hear Res Source Type: research

Communication pathways to and from the inner ear and their contributions to drug delivery.
Abstract The environment of the inner ear is highly regulated in a manner that some solutes are permitted to enter while others are excluded or transported out. Drug therapies targeting the sensory and supporting cells of the auditory and vestibular systems require the agent to gain entry to the fluid spaces of the inner ear, perilymph or endolymph, which surround the sensory organs. Access to the inner ear fluids from the vasculature is limited by the blood-labyrinth barriers, which include the blood-perilymph and blood-strial barriers. Intratympanic applications provide an alternative approach in which drugs are...
Source: Hearing Research - December 19, 2017 Category: Audiology Authors: Salt AN, Hirose K Tags: Hear Res Source Type: research

Non-tip auditory-nerve responses that are suppressed by low-frequency bias tones originate from reticular lamina motion.
Abstract Recent cochlear mechanical measurements show that active processes increase the motion response of the reticular lamina (RL) at frequencies more than an octave below the local characteristic frequency (CF) for CFs above 5 kHz. A possible correlate is that in high-CF (>5 kHz) auditory-nerve (AN) fibers, responses to frequencies 1-3 octaves below CF ("tail" frequencies) can be inhibited by medial olivocochlear (MOC) efferents. These results indicate that active processes enhance the sensitivity of tail-frequency RL and AN responses. Perhaps related is that some apical low-CF AN fibers have ...
Source: Hearing Research - December 14, 2017 Category: Audiology Authors: Nam H, Guinan JJ Tags: Hear Res Source Type: research

Electrically-evoked auditory steady-state responses as neural correlates of loudness growth in cochlear implant users.
This study investigated whether electrically-evoked auditory steady-state response amplitude growth functions correspond to behaviorally measured loudness growth functions. Seven cochlear implant listeners participated in two behavioral loudness growth tasks and an EEG recording session. The 40-Hz sinusoidally amplitude-modulated pulse trains were presented to CI channels stimulating at a more apical and basal region of the cochlea, and were presented at different current levels encompassing the listeners' dynamic ranges. Behaviorally, loudness growth was measured using an Absolute Magnitude Estimation and a Graphic Rating...
Source: Hearing Research - December 8, 2017 Category: Audiology Authors: Van Eeckhoutte M, Wouters J, Francart T Tags: Hear Res Source Type: research

Self reported hearing difficulty, tinnitus, and normal audiometric thresholds, the National Health and Nutrition Examination Survey 1999-2002.
Abstract Perceived hearing difficulty (HD) and/or tinnitus in the presence of normal audiometric thresholds present a clinical challenge. Yet, there is limited data regarding prevalence and determinant factors contributing to HD. Here we present estimates generalized to the non-institutionalized population of the United States based on the cross-sectional population-based study, the National Health and Nutrition and Examination Survey (NHANES) in 2176 participants (20-69 years of age). Normal audiometric thresholds were defined by pure-tone average (PTA4) of 0.5, 1.0, 2.0, 4.0 kHz ≤ 25 dBHL ...
Source: Hearing Research - December 7, 2017 Category: Audiology Authors: Spankovich C, Gonzalez VB, Su D, Bishop CE Tags: Hear Res Source Type: research

Frequency selectivity in macaque monkeys measured using a notched-noise method.
Abstract The auditory system is thought to process complex sounds through overlapping bandpass filters. Frequency selectivity as estimated by auditory filters has been well quantified in humans and other mammalian species using behavioral and physiological methodologies, but little work has been done to examine frequency selectivity in nonhuman primates. In particular, knowledge of macaque frequency selectivity would help address the recent controversy over the sharpness of cochlear tuning in humans relative to other animal species. The purpose of our study was to investigate the frequency selectivity of macaque m...
Source: Hearing Research - November 28, 2017 Category: Audiology Authors: Burton JA, Dylla ME, Ramachandran R Tags: Hear Res Source Type: research

A framework for testing and comparing binaural models.
This article discusses a number of current unresolved or disputed issues in binaural modelling, as well as some of the significant challenges in comparing binaural models with each other and with the experimental data. We introduce an auditory model framework, which we believe can become a useful infrastructure for resolving some of the current controversies. It operates models over the same paradigms that are used experimentally. The core of the proposed framework is an interface that connects three components irrespective of their underlying programming language: The experiment software, an auditory pathway model, and ta...
Source: Hearing Research - November 28, 2017 Category: Audiology Authors: Dietz M, Lestang JH, Majdak P, Stern RM, Marquardt T, Ewert SD, Hartmann WM, Goodman DFM Tags: Hear Res Source Type: research