Perceptually aligning apical frequency regions leads to more binaural fusion of speech in a CI simulation.
Abstract For bilateral cochlear implant users, the left and right arrays are typically not physically aligned, resulting in a degradation of binaural fusion, which can be detrimental to binaural abilities. Perceptually aligning the two arrays can be accomplished by disabling electrodes in one ear that do not have a perceptually corresponding electrode in the other side. However, disabling electrodes at the edges of the array will cause compression of the input frequency range into a smaller cochlear extent, which may result in reduced spectral resolution. An alternative approach to overcome this mismatch would be ...
Source: Hearing Research - May 17, 2016 Category: Audiology Authors: Staisloff HE, Lee DH, Aronoff JM Tags: Hear Res Source Type: research

Loss of glycine receptors containing the α3 subunit compromises auditory nerve activity, but not outer hair cell function.
Loss of glycine receptors containing the α3 subunit compromises auditory nerve activity, but not outer hair cell function. Hear Res. 2016 May 18; Authors: Dlugaiczyk J, Hecker D, Neubert C, Buerbank S, Campanelli D, Becker CM, Betz H, Knipper M, Rüttiger L, Schick B Abstract Inhibitory glycine receptors containing the α3 subunit (GlyRα3) regulate sensory information processing in the CNS and retina. In previous work, we demonstrated the presence of postsynaptic GlyR alpha3 immunoreactivity at efferent synapses of the medial and lateral olivocochlear bundle in the organ of Corti;...
Source: Hearing Research - May 17, 2016 Category: Audiology Authors: Dlugaiczyk J, Hecker D, Neubert C, Buerbank S, Campanelli D, Becker CM, Betz H, Knipper M, Rüttiger L, Schick B Tags: Hear Res Source Type: research

EEG activity evoked in preparation for multi-talker listening by adults and children.
Abstract Selective attention is critical for successful speech perception because speech is often encountered in the presence of other sounds, including the voices of competing talkers. Faced with the need to attend selectively, listeners perceive speech more accurately when they know characteristics of upcoming talkers before they begin to speak. However, the neural processes that underlie the preparation of selective attention for voices are not fully understood. The current experiments used electroencephalography (EEG) to investigate the time course of brain activity during preparation for an upcoming talker in...
Source: Hearing Research - May 9, 2016 Category: Audiology Authors: Holmes E, Kitterick PT, Summerfield AQ Tags: Hear Res Source Type: research

Horizontal Sound Localization in Cochlear Implant Users with a Contralateral Hearing Aid.
Abstract Interaural differences in sound arrival time (ITD) and in level (ILD) enable us to localize sounds in the horizontal plane, and can support source segregation and speech understanding in noisy environments. It is uncertain whether these cues are also available to hearing-impaired listeners who are bimodally fitted, i.e. with a cochlear implant (CI) and a contralateral hearing aid (HA). Here, we assessed sound localization behavior of fourteen bimodal listeners, all using the same Phonak HA and an Advanced Bionics CI processor, matched with respect to loudness growth. We aimed to determine the availability...
Source: Hearing Research - May 9, 2016 Category: Audiology Authors: Veugen LC, Hendrikse MM, van Wanrooij MM, Agterberg MJ, Chalupper J, Mens LH, Snik AF, John van Opstal A Tags: Hear Res Source Type: research

Aging effects on the Binaural Interaction Component of the Auditory Brainstem Response in the Mongolian Gerbil: Effects of Interaural Time and Level Differences.
Abstract The effect of interaural time difference (ITD) and interaural level difference (ILD) on wave 4 of the binaural and summed monaural auditory brainstem responses (ABRs) as well as on the DN1 component of the binaural interaction component (BIC) of the ABR in young and old Mongolian gerbils (Meriones unguiculatus) was investigated. Measurements were made at a fixed sound pressure level (SPL) and a fixed level above visually detected ABR threshold to compensate for individual hearing threshold differences. In both stimulation modes (fixed SPL and fixed level above visually detected ABR threshold) an effect of...
Source: Hearing Research - May 8, 2016 Category: Audiology Authors: Laumen G, Tollin DJ, Beutelmann R, Klump GM Tags: Hear Res Source Type: research

Long-term treatment with aldosterone slows the progression of age-related hearing loss.
Abstract Age-related hearing loss (ARHL), clinically referred to as presbycusis, is one of the three most prevalent chronic medical conditions of our elderly, with the majority of persons over the age of 60 suffering from some degree of ARHL. The progressive loss of auditory sensitivity and perceptual capability results in significant declines in workplace productivity, quality of life, cognition and abilities to communicate effectively. Aldosterone is a mineralocorticoid hormone produced in the adrenal glands and plays a role in the maintenance of key ion pumps, including the Na-K+-Cl co-transporter 1 or NKCC1, w...
Source: Hearing Research - May 4, 2016 Category: Audiology Authors: Halonen J, Hinton A, Frisina RD, Ding B, Zhu X, Walton JP Tags: Hear Res Source Type: research

Frequency selectivity of the human cochlea: Suppression tuning of spontaneous otoacoustic emissions.
Abstract Frequency selectivity is a key functional property of the inner ear and since hearing research began, the frequency resolution of the human ear has been a central question. In contrast to animal studies, which permit invasive recording of neural activity, human studies must rely on indirect methods to determine hearing selectivity. Psychophysical studies, which used masking of a tone by other sounds, indicate a modest frequency selectivity in humans. By contrast, estimates using the phase delays of stimulus-frequency otoacoustic emissions (SFOAE) predict a remarkably high selectivity, unique among mammals...
Source: Hearing Research - April 28, 2016 Category: Audiology Authors: Manley GA, van Dijk P Tags: Hear Res Source Type: research

MEMRO 2015 - Basic Science meets Clinical Otology.
PMID: 27130517 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 25, 2016 Category: Audiology Authors: Gaihede M, Dirckx J, von Unge M, Rosowski JJ Tags: Hear Res Source Type: research

Cochlear implant and inflammation reaction: safety study of a new steroid-eluting electrode.
Abstract Dexamethasone is a common anti-inflammatory agent added to cochlear implants to reduce hearing loss due to electrode insertion trauma. We evaluated the safety of eluting silicone rods containing 10% dexamethasone in a Guinea pig model. Animals were implanted with a dexamethasone eluting silicone electrode (DER) or with a non-eluting electrode (NER). The control group only underwent a cochleostomy (CS). Prior to implantation and during the two weeks following implantation, the hearing status of the animals was assessed by means of Compound Action Potentials (CAPs) with an electrode placed near the round wi...
Source: Hearing Research - April 20, 2016 Category: Audiology Authors: Astolfi L, Simoni E, Giarbini N, Giordano P, Pannella M, Hatzopoulos S, Martini A Tags: Hear Res Source Type: research

Transmucosal Gas-Loss Rates in Middle Ears Initially Filled with O2 or CO2.
This study investigates the role of different gases in clearance of gas in the middle ear cavity (ME) by its mucosal blood flow. A rat model was used to measure gas volume changes in the ME cavity at constant pressure without ventilation. We disturbed the normal gas composition of the ME by filling it with O2 or CO2, measured the consequent changes in gas volume over time and compared these results with previously obtained ones for air and N2. The first 5 min of the primary transient phase (phase I) for O2 or CO2 was characterized by a volume loss decrease of -0.49 ± 0.34 μL and -46.28 ± 8.49 μL, respec...
Source: Hearing Research - April 18, 2016 Category: Audiology Authors: Kania RE, Verillaud B, Ars B, Ba Huy PT, Herman P, Ar A Tags: Hear Res Source Type: research

The contribution of visual information to the perception of speech in noise with and without informative temporal fine structure.
Abstract Understanding what is said in demanding listening situations is assisted greatly by looking at the face of a talker. Previous studies have observed that normal-hearing listeners can benefit from this visual information when a talker's voice is presented in background noise. These benefits have also been observed in quiet listening conditions in cochlear-implant users, whose device does not convey the informative temporal fine structure cues in speech, and when normal-hearing individuals listen to speech processed to remove these informative temporal fine structure cues. The current study (1) characterised...
Source: Hearing Research - April 12, 2016 Category: Audiology Authors: Stacey PC, Kitterick PT, Morris SD, Sumner CJ Tags: Hear Res Source Type: research

Tonal frequency affects amplitude but not topography of rhesus monkey cranial EEG components.
Abstract The rhesus monkey is an important model of human auditory function in general and auditory deficits in neuro-psychiatric diseases such as schizophrenia in particular. Several rhesus monkey studies have described homologs of clinically relevant auditory evoked potentials such as pitch-based mismatch negativity, a fronto-central negativity that can be observed when a series of regularly repeating sounds is disrupted by a sound of different tonal frequency. As a result it is well known how differences of tonal frequency are represented in rhesus monkey EEG. However, to date there is no study that systematica...
Source: Hearing Research - April 12, 2016 Category: Audiology Authors: Teichert T Tags: Hear Res Source Type: research

Categorization of common sounds by cochlear implanted and normal hearing adults.
Abstract Auditory categorization involves grouping of acoustic events along one or more shared perceptual dimensions which can relate to both semantic and physical attributes. This process involves both high level cognitive processes (categorization) and low-level perceptual encoding of the acoustic signal, both of which are affected by the use of a cochlear implant (CI) device. The goal of this study was twofold: I) compare the categorization strategies of CI users and normal hearing listeners (NHL) II) investigate if any characteristics of the raw acoustic signal could explain the results. 16 experienced CI user...
Source: Hearing Research - April 1, 2016 Category: Audiology Authors: Collett E, Marx M, Gaillard P, Roby B, Fraysse B, Deguine O, Barone P Tags: Hear Res Source Type: research

Fully implantable hearing aid in the incudostapedial joint gap.
rt T Abstract A fully implantable hearing aid is introduced which is a combined sensor-actuator-transducer designed for insertion into the incudostapedial joint gap (ISJ). The active elements each consist of a thin titanium membrane with an applied piezoelectric single crystal. The effectiveness of the operating principle is verified in a temporal bone study. We also take a closer look at the influence of an implantation-induced increase in middle ear stiffness on the transducer's output. An assembly of the transducer with 1 mm thickness is built and inserted into six temporal bones. At this thickness, the stiffne...
Source: Hearing Research - March 30, 2016 Category: Audiology Authors: Koch M, Eßinger TM, Stoppe T, Lasurashvili N, Bornitz M, Zahnert T Tags: Hear Res Source Type: research

Response to Letter : Psychometric properties of the Tinnitus Functional Index (TFI): Assessment in a UK research volunteer population.
PMID: 27039256 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - March 29, 2016 Category: Audiology Authors: Fackrell K, Hall DA, Barry JG, Hoare DJ Tags: Hear Res Source Type: research

Coupling of an active middle-ear implant to the long process of the incus using an elastic clip attachment.
In conclusion, attachment of the FMT to the LPI with the LP coupler leads to generally good mechanical and functional coupling in temporal-bone preparations with a notable disadvantage between 1.8 and 6 kHz. Due to its elastic clip attachment it is expected that the LP coupler will reduce the risk of necrosis of the incus long process, which has to been shown in further studies. Clinical results of the LP coupler are pending. PMID: 27037037 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - March 28, 2016 Category: Audiology Authors: Schraven SP, Mlynski R, Dalhoff E, Heyd A, Wildenstein D, Rak K, Radeloff A, Hagen R, Gummer AW Tags: Hear Res Source Type: research

Intraoperative assessment of ossicular fixation.
We report measurements of the vibration response at the umbo, the tip of the incus long process and the lateral posterior crus of the stapes before and after artificially fixing the stapes footplate and anterior mallear ligament with luting cement. Results were obtained on temporal bones, but the practicality of the method allows easy clinical implementation. Velocity ratios between different measurement points along the ossicular chain may provide a quantitative indication of the degree of stapes fixation. Isolated anterior mallear ligament fixation was not distinguishable from the unfixed condition. PMID: 27034152 [...
Source: Hearing Research - March 27, 2016 Category: Audiology Authors: Peacock J, Dirckx J, von Unge M Tags: Hear Res Source Type: research

Balancing current levels in children with bilateral cochlear implants using electrophysiological and behavioral measures.
Abstract Children have benefited from bilateral cochlear implants (CIs) over unilateral CIs despite often missing important periods in bilateral auditory development. This suggests a remarkable perceptual ability by children to "work around" abnormal changes in the auditory pathways. Nonetheless, these children rely primarily on interaural level differences as interaural timing cues are more difficult to access or detect. Mismatched levels provided to the two implants could distort interaural level cues thus compromising the benefits of bilateral CI use. We asked whether "balanced" or "cen...
Source: Hearing Research - March 24, 2016 Category: Audiology Authors: Gordon KA, Abbasalipour P, Papsin BC Tags: Hear Res Source Type: research

The afferent signaling complex: regulation of type I spiral ganglion neuron responses in the auditory periphery.
Abstract The spiral ganglion neurons (SGNs) are the first action potential generating neurons in the auditory pathway. The type I SGNs contact the sensory inner hair cells via their peripheral dendrites and relay auditory information to the brainstem via their central axon fibers. Individual afferent fibers show differences in response properties that are essential for normal hearing. The mechanisms that give rise to the heterogeneity of afferent responses are very poorly understood but are likely already in place at the peripheral dendrites where synapses are formed and action potentials are generated. To identif...
Source: Hearing Research - March 23, 2016 Category: Audiology Authors: Reijntjes DO, Pyott SJ Tags: Hear Res Source Type: research

The Calyx of Held in the auditory system: structure, function, and development.
Abstract The calyx of Held synapse plays an important role in the auditory system, relaying information about sound localization via fast and precise synaptic transmission, which is achieved by its specialized structure and giant size. During development, the calyx of Held undergoes anatomical, morphological, and physiological changes necessary for performing its functions. The large dimensions of the calyx of Held nerve terminal are well suited for direct electrophysiological recording of many presynaptic events that are difficult, if not impossible to record at small conventional synapses. This unique accessibil...
Source: Hearing Research - March 23, 2016 Category: Audiology Authors: Baydyuk M, Xu J, Wu LG Tags: Hear Res Source Type: research

Spectral and binaural loudness summation for hearing-impaired listeners.
Abstract Sensorineural hearing loss typically results in a steepened loudness function and a reduced dynamic range from elevated thresholds to uncomfortably loud levels for narrowband and broadband signals. Restoring narrowband loudness perception for hearing-impaired (HI) listeners can lead to overly loud perception of broadband signals and it is unclear how binaural presentation affects loudness perception in this case. Here, loudness perception quantified by categorical loudness scaling for nine normal-hearing (NH) and ten HI listeners was compared for signals with different bandwidth and different spectral sha...
Source: Hearing Research - March 18, 2016 Category: Audiology Authors: Oetting D, Hohmann V, Appell JE, Kollmeier B, Ewert SD Tags: Hear Res Source Type: research

Auditory steady-state responses in cochlear implant users: Effect of modulation frequency and stimulation artifacts.
Abstract Previous studies have shown that objective measures based on stimulation with low-rate pulse trains fail to predict the threshold levels of cochlear implant (CI) users for high-rate pulse trains, as used in clinical devices. Electrically evoked auditory steady-state responses (EASSRs) can be elicited by modulated high-rate pulse trains, and can potentially be used to objectively determine threshold levels of CI users. The responsiveness of the auditory pathway of profoundly hearing-impaired CI users to modulation frequencies is, however, not known. In the present study we investigated the responsiveness o...
Source: Hearing Research - March 16, 2016 Category: Audiology Authors: Gransier R, Deprez H, Hofmann M, Moonen M, van Wieringen A, Wouters J Tags: Hear Res Source Type: research

The effect of noise exposure during the developmental period on the function of the auditory system.
J, Syka J Abstract Recently, there has been growing evidence that development and maturation of the auditory system depends substantially on the afferent activity supplying inputs to the developing centers. In cases when this activity is altered during early ontogeny as a consequence of, e.g., an unnatural acoustic environment or acoustic trauma, the structure and function of the auditory system may be severely affected. Pathological alterations may be found in populations of ribbon synapses of the inner hair cells, in the structure and function of neuronal circuits, or in auditory driven behavioral and psychoph...
Source: Hearing Research - March 15, 2016 Category: Audiology Authors: Bureš Z, Popelář J, Syka J Tags: Hear Res Source Type: research

Design, Fabrication, and In Vitro Testing of Novel Three-Dimensionally Printed Tympanic Membrane Grafts.
This study demonstrates the design, fabrication and preliminary in vitro acoustic and mechanical evaluation of 3D printed TM grafts. Data illustrate the feasibility of creating TM grafts with acoustic properties that reflect sound induced motion patterns of the human TM; furthermore, 3D printed grafts have mechanical properties that demonstrate increased resistance to deformation compared to temporalis fascia. PMID: 26994661 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - March 15, 2016 Category: Audiology Authors: Kozin ED, Black NL, Cheng JT, Cotler MJ, McKenna MJ, Lee DJ, Lewis JA, Rosowski JJ, Remenschneider AK Tags: Hear Res Source Type: research

Time-frequency decomposition of click evoked otoacoustic emissions in children.
This study investigated the time-frequency properties of CEOAEs in 5 to 10 year old children. In the first part, we examined the feasibility of the S transform to characterize the time-frequency features of CEOAEs. A synthetic signal with known gammatones was analyzed using the S transform, as well as a wavelet transform with the basis function used traditionally for CEOAE analysis. The S and wavelet transforms provided similar representations of the gammatones of the synthetic signal in the mid and high frequencies. However, the S transform yielded a slightly more precise time-frequency representation at low frequencies (...
Source: Hearing Research - March 11, 2016 Category: Audiology Authors: Mishra SK, Biswal M Tags: Hear Res Source Type: research

Effects of high intensity noise on the vestibular system in rats.
Abstract Some individuals with noise-induced hearing loss (NIHL) also report balance problems. These accompanying vestibular complaints are not well understood. The present study used a rat model to examine the effects of noise exposure on the vestibular system. Rats were exposed to continuous broadband white noise (0-24kHz) at an intensity of 116dB sound pressure level (SPL) via insert ear phones in one ear for three hours under isoflurane anesthesia. Seven days after the exposure, a significant increase in ABR threshold (43.3+1.9dB) was observed in the noise-exposed ears, indicating hearing loss. Effects of nois...
Source: Hearing Research - March 9, 2016 Category: Audiology Authors: Stewart C, Yu Y, Huang J, Maklad A, Tang X, Allison J, Mustain W, Zhou W, Zhu H Tags: Hear Res Source Type: research

Effects of pulsatile electrical stimulation of the round window on central hyperactivity after cochlear trauma in guinea pig.
This study aimed to investigate the effects of electrical stimulation in the form of brief biphasic shocks delivered to the round window of the cochlea on the spontaneous firing rates of hyperactive inferior colliculus neurons following acoustic trauma in guinea pigs. Effects during the stimulation itself included both inhibition and excitation but spontaneous firing was suppressed for up to hundreds of ms after the cessation of the shock train in all sampled hyperactive neurons. Pharmacological block of olivocochlear efferent action on outer hair cells did not eliminate the prolonged suppression observed in inferior colli...
Source: Hearing Research - March 9, 2016 Category: Audiology Authors: Mulders WH, Spencer TC, Robertson D Tags: Hear Res Source Type: research

Impulse noise injury prediction based on the cochlear energy.
Abstract The current impulse noise criteria for the protection against impulse noise injury do not incorporate an objective measure of hearing protection. A new biomechanically-based model has been developed based on improvement of the Auditory Hazard Assessment Algorithm for the Human (AHAAH) using the integrated cochlear energy (ICE) as the damage risk correlate (DRC). The model parameters have been corrected using the latest literature data. The anomalous dose-response inversion behavior of the AHAAH model was eliminated. The modeling results show that the annular ligament (AL) parameters are the dominant cause...
Source: Hearing Research - March 8, 2016 Category: Audiology Authors: Zagadou B, Chan P, Ho K, Shelley D Tags: Hear Res Source Type: research

Disrupted Functional Brain Connectome in Unilateral Sudden Sensorineural Hearing Loss.
Abstract Sudden sensorineural hearing loss (SSNHL) is generally defined as sensorineural hearing loss of 30 dB or greater over at least three contiguous audiometric frequencies and within a three-day period. This hearing loss is usually unilateral and can be associated with tinnitus and vertigo. The pathogenesis of unilateral sudden sensorineural hearing loss is still unknown, and the alterations in the functional connectivity are suspected to involve one possible pathogenesis. Despite scarce findings with respect to alterations in brain functional networks in unilateral sudden sensorineural hearing loss, the alte...
Source: Hearing Research - March 8, 2016 Category: Audiology Authors: Xu H, Fan W, Zhao X, Li J, Zhang W, Lei P, Liu Y, Wang H, Cheng H, Shi H Tags: Hear Res Source Type: research

Congestion of mastoid mucosa and influence on middle ear pressure - effect of retroauricular injection of adrenaline.
Abstract Micro-CT scanning of temporal bones has revealed numerous retroauricular microchannels, which connect the outer bone surface directly to the underlying mastoid air cells. Their structure and dimensions have suggested a separate vascular supply to the mastoid mucosa, which may play a role in middle ear (ME) pressure regulation. This role may be accomplished by changes in the mucosa congestion resulting in volumetric changes, which ultimately affect the pressure of the enclosed ME gas pocket (Boyle's law). Further, such mucosa congestion may be susceptible to α-adrenergic stimulation similar to the mu...
Source: Hearing Research - March 2, 2016 Category: Audiology Authors: Fooken Jensen PV, Gaihede M Tags: Hear Res Source Type: research

Perinatal Thiamine Deficiency Causes Cochlear Innervation Abnormalities in Mice.
Abstract Neonatal thiamine deficiency can cause auditory neuropathy in humans. To probe the underlying cochlear pathology, mice were maintained on a thiamine-free or low-thiamine diet during fetal development or early postnatal life. At postnatal ages from 18 days to 22 wks, cochlear function was tested and cochlear histopathology analyzed by plastic sections and cochlear epithelial whole-mounts immunostained for neuronal and synaptic markers. Although none of the thiamine-deprivation protocols resulted in any loss of hair cells or any obvious abnormalities in the non-sensory structures of the cochlear duct, all t...
Source: Hearing Research - March 1, 2016 Category: Audiology Authors: Maison SF, Yin Y, Liberman LD, Liberman MC Tags: Hear Res Source Type: research

HEI-OC1 Cells as a Model for Investigating Drug Cytotoxicity.
Abstract The House Ear Institute-Organ of Corti 1 (HEI-OC1) is one of the few, and arguable the most used, mouse auditory cell line available for research purposes. Originally proposed as an in vitro system for screening of ototoxic drugs, it has been used to investigate, among other topics, apoptotic pathways, autophagy and senescence, mechanism of cell protection, inflammatory responses, cell differentiation, effects of hypoxia, oxidative and endoplasmic reticulum stress, and expression of molecular channels and receptors. However, the use of different techniques with different goals resulted in apparent contrad...
Source: Hearing Research - February 27, 2016 Category: Audiology Authors: Kalinec G, Thein P, Park C, Kalinec F Tags: Hear Res Source Type: research

Human Audiometric Thresholds do not Predict Specific Cellular Damage in the Inner Ear.
CONCLUSIONS: Audiometric thresholds do not predict specific cellular damage in the human inner ear. Our study highlights the need for better non- or minimally-invasive tools, such as cochlear endoscopy, to establish cellular-level diagnosis and thereby guide therapy and monitor response to treatment. PMID: 26924453 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 25, 2016 Category: Audiology Authors: Landegger LD, Psaltis D, Stankovic KM Tags: Hear Res Source Type: research

Middle-ear and inner-ear contribution to bone bonduction in chinchilla: The development of Carhart's notch.
We present acoustical measurements of sound in the inner ear that separate out the components of BC stimulation that stimulate the inner ear via ossicular motion (compression of the walls of the ear canal or ossicular inertia) from the components that act directly on the cochlea (cochlear compression or inertia, and extra-cochlear 'third-window' pathways). The results are consistent with our earlier suggestion that the inner-ear mechanisms play a large role in bone-conduction stimulation in the chinchilla at all frequencies. However, the data also suggest the pathways that conduct vibration to the inner ear via ossicular-m...
Source: Hearing Research - February 23, 2016 Category: Audiology Authors: Chhan D, Bowers P, McKinnon ML, Rosowski JJ Tags: Hear Res Source Type: research

Graded and discontinuous EphA-ephrinB expression patterns in the developing auditory brainstem.
Abstract Eph-ephrin interactions guide topographic mapping and pattern formation in a variety of systems. In contrast to other sensory pathways, their precise role in the assembly of central auditory circuits remains poorly understood. The auditory midbrain, or inferior colliculus (IC) is an intriguing structure for exploring guidance of patterned projections as adjacent subdivisions exhibit distinct organizational features. The central nucleus of the IC (CNIC) and deep aspects of its neighboring lateral cortex (LCIC, Layer 3) are tonotopically-organized and receive layered inputs from primarily downstream auditor...
Source: Hearing Research - February 20, 2016 Category: Audiology Authors: Wallace MM, Harris JA, Brubaker DQ, Klotz CA, Gabriele ML Tags: Hear Res Source Type: research

Can place-specific cochlear dispersion be represented by auditory steady-state responses?
Abstract The present study investigated to what extent properties of local cochlear dispersion can be objectively assessed through auditory steady-state responses (ASSR). The hypothesis was that stimuli compensating for the phase response at a particular cochlear location generate a maximally modulated basilar membrane (BM) response at that BM position, due to the large "within-channel" synchrony of activity. This, in turn, leads to a larger ASSR amplitude than other stimuli of corresponding intensity and bandwidth. Two stimulus types were chosen: 1] Harmonic tone complexes consisting of equal-amplitude ...
Source: Hearing Research - February 20, 2016 Category: Audiology Authors: Gallardo AP, Epp B, Dau T Tags: Hear Res Source Type: research

Anatomical and physiological development of the human inner ear.
We describe the development of the human inner ear with the invagination of the otic vesicle at 4 weeks gestation (WG), the growth of the semicircular canals from 5 WG, and the elongation and coiling of the cochlea at 10 WG. As the membranous labyrinth takes shape, there is a concomitant development of the sensory neuroepithelia and their associated structures within. This review details the growth and differentiation of the vestibular and auditory neuroepithelia, including synaptogenesis, the expression of stereocilia and kinocilia, and innervation of hair cells by afferent and efferent nerve fibres. Along with developmen...
Source: Hearing Research - February 18, 2016 Category: Audiology Authors: Lim R, Brichta AM Tags: Hear Res Source Type: research

Musical experience sharpens human cochlear tuning.
Abstract The mammalian cochlea functions as a filter bank that performs a spectral, Fourier-like decomposition on the acoustic signal. While tuning can be compromised (e.g., broadened with hearing impairment), whether or not human cochlear frequency resolution can be sharpened through experiential factors (e.g., training or learning) has not yet been established. Previous studies have demonstrated sharper psychophysical tuning curves in trained musicians compared to nonmusicians, implying superior peripheral tuning. However, these findings are based on perceptual masking paradigms, and reflect engagement of the en...
Source: Hearing Research - February 18, 2016 Category: Audiology Authors: Bidelman GM, Nelms C, Bhagat SP Tags: Hear Res Source Type: research

Functional magnetic resonance imaging confirms forward suppression for rapidly alternating sounds in human auditory cortex but not in the inferior colliculus.
Abstract Forward suppression at the level of the auditory cortex has been suggested to subserve auditory stream segregation. Recent results in non-streaming stimulation contexts have indicated that forward suppression can also be observed in the inferior colliculus; whether this holds for streaming-related contexts remains unclear. Here, we used cardiac-gated fMRI to examine forward suppression in the inferior colliculus (and the rest of the human auditory pathway) in response to canonical streaming stimuli (rapid tone sequences comprised of either one repetitive tone or two alternating tones). The first stimulus ...
Source: Hearing Research - February 17, 2016 Category: Audiology Authors: Uhlig CH, Dykstra AR, Gutschalk A Tags: Hear Res Source Type: research

Vestibular function is associated with residual low-frequency hearing loss in patients with bi-allelic mutations in the SLC26A4 gene.
In conclusion, DFNB4 shows vestibular dysfunction, which is strongly linked to hearing loss at low frequencies without any allelic or anatomical predisposing factor. PMID: 26900070 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 17, 2016 Category: Audiology Authors: Jung J, Seo YW, Choi JY, Kim SH Tags: Hear Res Source Type: research

Reply to: Psychometric properties of the Tinnitus Functional Index (TFI): Assessment in a UK research volunteer population.
PMID: 26900071 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 17, 2016 Category: Audiology Authors: Folmer RL Tags: Hear Res Source Type: research

Morphology and microchemistry of the otoliths of the inner ear of anuran larvae.
Morphology and microchemistry of the otoliths of the inner ear of anuran larvae. Hear Res. 2016 Feb 16; Authors: Bassó A, Peltzer PM, Lajmanovich RC, Attademo AM, Junges CM, Chialvo DR Abstract To navigate in space most vertebrates need precise positional cues provided by a variety of sensors, including structures in the inner ear, which are exquisitely sensitive to gravity and linear acceleration. Although these structures have been described in many vertebrates, no information is available for anuran larvae. The purpose of our study was to describe, for the first time, the size, complexi...
Source: Hearing Research - February 16, 2016 Category: Audiology Authors: Bassó A, Peltzer PM, Lajmanovich RC, Attademo AM, Junges CM, Chialvo DR Tags: Hear Res Source Type: research

Electrode array-eluted dexamethasone protects against electrode insertion trauma induced hearing and hair cell losses, damage to neural elements, increases in impedance and fibrosis: A dose response study.
In conclusion, DXMb eluting electrodes protected the cochlea against long term increases in hearing thresholds, loss of hair cells, damage to neural elements and increases in impedance and fibrosis that result from EIT-initiated damage. The protection achieved by DXMb-eluting electrodes was dose dependent. Establishing a significant level of trauma induced elevation in hearing thresholds was important for the determination of the otoprotective effects of array-eluted DXMb. PMID: 26892906 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 15, 2016 Category: Audiology Authors: Bas E, Bohorquez J, Goncalves S, Perez E, Dinh CT, Garnham C, Hessler R, Eshraghi AA, Van De Water TR Tags: Hear Res Source Type: research

Functional near-infrared spectroscopy for neuroimaging in cochlear implant recipients.
Abstract Functional neuroimaging can provide insight into the neurobiological factors that contribute to the variations in individual hearing outcomes following cochlear implantation. To date, measuring neural activity within the auditory cortex of cochlear implant (CI) recipients has been challenging, primarily because the use of traditional neuroimaging techniques is limited in people with CIs. Functional near-infrared spectroscopy (fNIRS) is an emerging technology that offers benefits in this population because it is non-invasive, compatible with CI devices, and not subject to electrical artifacts. However, the...
Source: Hearing Research - February 13, 2016 Category: Audiology Authors: Saliba J, Bortfeld H, Levitin DJ, Oghalai JS Tags: Hear Res Source Type: research

Response of the human tympanic membrane to transient acoustic and mechanical stimuli.
Abstract The response of the tympanic membrane (TM) to transient environmental sounds and the contributions of different parts of the TM to middle-ear sound transmission were investigated by measuring the TM response to global transients (acoustic clicks) and to local transients (mechanical impulses) applied to the umbo and various locations on the TM. A lightly-fixed human temporal bone was prepared by removing the ear canal, inner ear, and stapes, leaving the incus, malleus, and TM intact. Motion of nearly the entire TM was measured by a digital holography system with a high speed camera at a rate of 42 000 fram...
Source: Hearing Research - February 12, 2016 Category: Audiology Authors: Razavi P, Ravicz ME, Dobrev I, Cheng JT, Furlong C, Rosowski JJ Tags: Hear Res Source Type: research

Sensitivity of the Cochlear Nerve to Acoustic and Electrical Stimulation Months After a Vestibular Labyrinthectomy in Guinea Pigs.
Abstract Single-sided deafness patients are now being considered candidates to receive a cochlear implant. With this, many people who have undergone a unilateral vestibular labyrinthectomy for the treatment of chronic vertigo are now being considered for cochlear implantation. There is still some concern regarding the potential efficacy of cochlear implants in these patients, where factors such as cochlear fibrosis or nerve degeneration following unilateral vestibular labyrinthectomy may preclude their use. Here, we have performed a unilateral vestibular labyrinthectomy in normally hearing guinea pigs, and allowed...
Source: Hearing Research - February 9, 2016 Category: Audiology Authors: Brown DJ, Mukherjee P, Pastras C, Gibson WP, Curthoys IS Tags: Hear Res Source Type: research

The role of connectivity and stochastic osteocyte behavior in the distribution of perilabyrinthine bone degeneration. A Monte Carlo based simulation study.
en MS Abstract Previous studies of undecalcified temporal bones labeled with fluorescent tissue time markers and basic fuchsine have documented the unique spatial and temporal patterns underlying inner ear bone development, morphology and degeneration, and has led to the identification of inner ear OPG as the candidate inhibiter of perilabyrinthine bone resorption. Resulting age related excessive matrix microdamage, osteocyte death and degeneration of the OPG signaling pathway is expected to trigger bone remodeling in the otic capsule, but when this happens the morphology of the remodeling bone is abnormal and the...
Source: Hearing Research - February 9, 2016 Category: Audiology Authors: Bloch SL, Sørensen MS Tags: Hear Res Source Type: research

HEI-OC1 Cells as a Model for Investigating Prestin Function.
Abstract The House Ear Institute-Organ of Corti 1 (HEI-OC1) is a mouse auditory cell line that endogenously express, among other several markers of cochlear hair cells, the motor protein prestin (SLC26A5). Since its discovery fifteen years ago, and because of the difficulties associated with working with outer hair cells, prestin studies have been performed mostly by expressing it exogenously in non-specific systems such as HEK293 and TSA201, embryonic kidney cells from human origin, or Chinese Hamster Ovary (CHO) cells. Here, we report flow cytometry and confocal laser scanning microscopy studies on the pattern o...
Source: Hearing Research - February 5, 2016 Category: Audiology Authors: Park C, Thein P, Kalinec G, Kalinec F Tags: Hear Res Source Type: research

A next-generation sequencing gene panel (MiamiOtoGenes) for comprehensive analysis of deafness genes.
Abstract Extreme genetic heterogeneity along with remarkable variation in the distribution of causative variants across in different ethnicities makes single gene testing inefficient for hearing loss. We developed a custom capture/next-generation sequencing gene panel of 146 known deafness genes with a total target size of approximately 1 MB. The genes were identified by searching databases including Hereditary Hearing Loss Homepage, the Human Genome Mutation Database (HGMD), Online Mendelian Inheritance in Man (OMIM) and most recent peer-reviewed publications related to the genetics of deafness. The design c...
Source: Hearing Research - February 2, 2016 Category: Audiology Authors: Tekin D, Yan D, Bademci G, Feng Y, Guo S, Foster J, Blanton S, Tekin M, Liu X Tags: Hear Res Source Type: research

Indication of Direct Acoustical Cochlea Stimulation in Comparison to Cochlear Implants.
r H Abstract The new implantable hearing system Codacs™ was designed to close the treatment gap between active middle ear implants and cochlear implants in cases of severe-to-profound mixed hearing loss. The Codacs™ actuator is attached to conventional stapes prosthesis during the implantation and thereby provides acoustical stimulation through a stapedotomy to the cochlea. Cochlear implants (CIs) on the other hand are an established treatment option for profoundly deaf patients including mixed hearing losses that are possible candidates for the Codacs™. In this retrospective study, we compared t...
Source: Hearing Research - January 30, 2016 Category: Audiology Authors: Kludt E, Büchner A, Schwab B, Lenarz T, Maier H Tags: Hear Res Source Type: research