Auditory perceptual load: A review.
Abstract Selective attention is a crucial mechanism in everyday life, allowing us to focus on a portion of incoming sensory information at the expense of other less relevant stimuli. The circumstances under which irrelevant stimuli are successfully ignored have been a topic of scientific interest for several decades now. Over the last 20 years, the perceptual load theory (e.g. Lavie, 1995) has provided one robust framework for understanding these effects within the visual modality. The suggestion is that successful selection depends on the perceptual demands imposed by the task-relevant information. However, less ...
Source: Hearing Research - February 7, 2017 Category: Audiology Authors: Murphy S, Spence C, Dalton P Tags: Hear Res Source Type: research

Abnormal regional activity and functional connectivity in resting-state brain networks associated with etiology confirmed unilateral pulsatile tinnitus in the early stage of disease.
This study was designed to demonstrate the functional network alterations in the patients with pulsatile tinnitus (PT). In this study, we recruited 45 patients with unilateral PT in the early stage of disease (less than 48 months of disease duration) and 45 normal controls. We used regional homogeneity (ReHo) and seed-based FC computational methods to reveal resting-state brain activity features associated with pulsatile tinnitus. Compared with healthy controls, PT patients showed regional abnormalities mainly in the left middle occipital gyrus (MOG), posterior cingulate gyrus (PCC), precuneus and right anterior insula (AI...
Source: Hearing Research - February 6, 2017 Category: Audiology Authors: Lv H, Zhao P, Liu Z, Li R, Zhang L, Wang P, Yan F, Liu L, Wang G, Zeng R, Li T, Dong C, Gong S, Wang Z Tags: Hear Res Source Type: research

Intelligibility in speech maskers with a binaural cochlear implant sound coding strategy inspired by the contralateral medial olivocochlear reflex.
on BS Abstract We have recently proposed a binaural cochlear implant (CI) sound processing strategy inspired by the contralateral medial olivocochlear reflex (the MOC strategy) and shown that it improves intelligibility in steady-state noise (Lopez-Poveda et al., 2016, Ear Hear 37:e138-e148). The aim here was to evaluate possible speech-reception benefits of the MOC strategy for speech maskers, a more natural type of interferer. Speech reception thresholds (SRTs) were measured in six bilateral and two single-sided deaf CI users with the MOC strategy and with a standard (STD) strategy. SRTs were measured in unilate...
Source: Hearing Research - February 6, 2017 Category: Audiology Authors: Lopez-Poveda EA, Eustaquio-Martín A, Stohl JS, Wolford RD, Schatzer R, Gorospe JM, Ruiz SS, Benito F, Wilson BS Tags: Hear Res Source Type: research

Identification of induced and naturally occurring conductive hearing loss in mice using bone conduction.
In this report, we investigate the use of air- and bone-conducted evoked auditory brainstem responses to perform a similar separation in mice. We describe a technique by which we stimulate the mouse ear both acoustically and via whole-head vibration. We investigate the sensitivity of this technique to conductive hearing loss by introducing middle-ear lesions in normal hearing mice. We also use the technique to investigate the presence of an age-related conductive hearing loss in a common mouse model of presbycusis, the BALB/c mouse. PMID: 28167132 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 2, 2017 Category: Audiology Authors: Chhan D, McKinnon ML, Rosowski JJ Tags: Hear Res Source Type: research

Auditory brainstem response latency in forward masking, a marker of sensory deficits in listeners with normal hearing thresholds.
Abstract In rodent models, acoustic exposure too modest to elevate hearing thresholds can nonetheless cause auditory nerve fiber deafferentation, interfering with the coding of supra-threshold sound. Low-spontaneous rate nerve fibers, important for encoding acoustic information at supra-threshold levels and in noise, are more susceptible to degeneration than high-spontaneous rate fibers. The change in auditory brainstem response (ABR) wave-V latency with noise level has been shown to be associated with auditory nerve deafferentation. Here, we measured ABR in a forward masking paradigm and evaluated wave-V latency ...
Source: Hearing Research - January 31, 2017 Category: Audiology Authors: Mehraei G, Paredes Gallardo A, Shinn-Cunningham BG, Dau T Tags: Hear Res Source Type: research

Analytical and numerical modeling of the hearing system: advances towards the assessment of hearing damage.
Abstract Hearing is an extremely complex phenomenon, involving a large number of interrelated variables that are difficult to measure in vivo. In order to investigate such process under simplified and well-controlled conditions, models of sound transmission have been developed through many decades of research. The value of modeling the hearing system is not only to explain the normal function of the hearing system and account for experimental and clinical observations, but to simulate a variety of pathological conditions that lead to hearing damage and hearing loss, as well as for development of auditory implants,...
Source: Hearing Research - January 31, 2017 Category: Audiology Authors: De Paolis A, Bikson M, Nelson JT, de Ru JA, Packer M, Cardoso L Tags: Hear Res Source Type: research

Prevalence of hearing loss and tinnitus in Iraq and Afghanistan veterans: A Chronic Effects of Neurotrauma Consortium study.
Abstract The purpose of this study was to describe the prevalence of hearing loss and tinnitus in a cohort of Iraq and Afghanistan veterans (IAV) with common post-deployment conditions, including traumatic brain injury (TBI), post-traumatic stress disorder (PTSD), and other typical post-concussive conditions such as headaches and vertigo/dizziness. This retrospective observational study used data from the national Veterans Health Administration (VA) data repository from fiscal years 2001-2014. Veteran data was included if there were at least three years of VA care, with one or more years of care in 2007 or after. ...
Source: Hearing Research - January 29, 2017 Category: Audiology Authors: Swan AA, Nelson JT, Swiger B, Jaramillo CA, Eapen BC, Packer M, Pugh MJ Tags: Hear Res Source Type: research

Frequency-dependent fine structure in the frequency-following response: The byproduct of multiple generators.
Abstract The frequency-following response (FFR) is an auditory-evoked response recorded at the scalp that captures the spectrotemporal properties of tonal stimuli. Previous investigations report that the amplitude of the FFR fluctuates as a function of stimulus frequency, a phenomenon thought to reflect multiple neural generators phase-locking to the stimulus with different response latencies. When phase-locked responses are offset by different latencies, constructive and destructive phase interferences emerge in the volume-conducted signals, culminating in an attenuation or amplification of the scalp-recorded res...
Source: Hearing Research - January 26, 2017 Category: Audiology Authors: Tichko P, Skoe E Tags: Hear Res Source Type: research

Auditory-visual integration in fields of the auditory cortex.
Abstract While multimodal interactions have been known to exist in the early sensory cortices, the response properties and spatiotemporal organization of these interactions are poorly understood. To elucidate the characteristics of multimodal sensory interactions in the cerebral cortex, neuronal responses to visual stimuli with or without auditory stimuli were investigated in core and belt fields of guinea pig auditory cortex using real-time optical imaging with a voltage-sensitive dye. On average, visual responses consisted of short excitation followed by long inhibition. Although visual responses were observed i...
Source: Hearing Research - January 19, 2017 Category: Audiology Authors: Kubota M, Sugimoto S, Hosokawa Y, Ojima H, Horikawa J Tags: Hear Res Source Type: research

Development and validation of the Speech Reception in Noise (SPRINT) Test.
Abstract Since 1992, the Speech Recognition in Noise Test, or SPRINT, has been the standard speech-in-noise test for assessing auditory fitness-for-duty of US Army Soldiers with hearing loss. The original SPRINT test consisted of 200 monosyllabic words presented at a Signal-to-Noise Ratio (SNR) of +9 dB in the presence of a six-talker babble noise. Normative data for the test was collected on 319 hearing impaired Soldiers, and a procedure for making recommendations about the disposition of military personnel on the basis of their SPRINT score and their years of experience was developed and implemented as part of U...
Source: Hearing Research - January 18, 2017 Category: Audiology Authors: Brungart DS, Walden B, Cord M, Phatak S, Theodoroff SM, Griest S, Grant KW Tags: Hear Res Source Type: research

Informational masking and the effects of differences in fundamental frequency and fundamental-frequency contour on phonetic integration in a formant ensemble.
This study explored the effects on speech intelligibility of across-formant differences in fundamental frequency (ΔF0) and F0 contour. Sentence-length speech analogues were presented dichotically (left = F1 + F3; right = F2), either alone or-because competition usually reveals grouping cues most clearly-accompanied in the left ear by a competitor for F2 (F2C) that listeners must reject to optimize recognition. F2C was created by inverting the F2 frequency contour. In experiment 1, all left-ear formants shared the same constant F0 and ΔF0F2 was 0 or ±4 semitones. In experimen...
Source: Hearing Research - January 17, 2017 Category: Audiology Authors: Summers RJ, Bailey PJ, Roberts B Tags: Hear Res Source Type: research

Metabotropic glutamate and GABA receptors modulate cellular excitability and glutamatergic transmission in chicken cochlear nucleus angularis neurons.
Abstract Neurons in the avian cochlear nucleus angularis (NA) receive glutamatergic input from the auditory nerve, and GABAergic input from the superior olivary nucleus. Physiologically heterogeneous, NA neurons perform multiple functions including encoding sound intensity information. Using in vitro whole-cell patch recordings from acute brain slices and immunohistochemistry staining, we investigated neuromodulation mediated by metabotropic glutamate and GABA receptors (mGluRs and GABABRs) in NA neurons. Based on their intrinsic firing patterns in response to somatic current injections, NA neurons were classified...
Source: Hearing Research - January 15, 2017 Category: Audiology Authors: Shi W, Lu Y Tags: Hear Res Source Type: research

Adding simultaneous stimulating channels to reduce power consumption in cochlear implants.
a W Abstract Sound coding strategies for Cochlear Implant (CI) listeners can be used to control the trade-off between speech performance and power consumption. Most commercial CI strategies use non-simultaneous channel stimulation, stimulating only one electrode at a time. One could add parallel simultaneous stimulating channels such that the electrical interaction between channels is increased. This would produce spectral smearing, because the electrical fields of the simultaneous stimulated channels interact, but also power savings. The parallel channels produce a louder sensation than sequential stimulation. To...
Source: Hearing Research - January 15, 2017 Category: Audiology Authors: Langner F, Saoji A, Büchner A, Nogueira W Tags: Hear Res Source Type: research

Using acoustic reflex threshold, auditory brainstem response and loudness judgments to investigate changes in neural gain following acute unilateral deprivation in normal hearing adults.
Abstract Unilateral auditory deprivation induces a reduction in the acoustic reflex threshold (ART) and an increase in loudness. These findings have been interpreted as a compensatory change in neural gain, governed by changes in excitatory and inhibitory neural inputs. There is also evidence to suggest that changes in neural gain can be measured using the auditory brainstem response (ABR). The present study extended Munro et al. (2014) [J. Acoust. Soc. Am. 135, 315-322] by investigating changes after 4 days of unilateral earplug use to: (i) ART, (ii) auditory brainstem response (ABR) and (iii) loudness. Because c...
Source: Hearing Research - January 12, 2017 Category: Audiology Authors: Brotherton H, Plack CJ, Schaette R, Munro KJ Tags: Hear Res Source Type: research

Broadening the Phenotype of DFNB28: Mutations in TRIOBP are associated with Moderate, Stable Hereditary Hearing Impairment.
Abstract DFNB28 is characterized by prelingual, severe to profound sensorineural hearing impairment (HI). It is associated with mutations in exon 6 and 7 of TRIOBP and has not been reported in the European population. Here, we describe two isolated cases of Dutch origin with congenital, moderate HI and compound heterozygous mutations in TRIOBP. Three of the mutations are novel, one nonsense mutation (c.5014G>T (p.Gly1672*)) and two frameshift mutations (c.2653del (p.Arg885Alafs*120) and c.3460_3461del (p.Leu1154Alafs*29)). The fourth mutation is the known c.3232dup (p.Arg1078Profs*6) mutation. Longitudinal audi...
Source: Hearing Research - January 11, 2017 Category: Audiology Authors: Wesdorp M, van de Kamp JM, Hensen EF, Schraders M, Oostrik J, Yntema HG, Feenstra I, Admiraal RJ, Kunst HP, Tekin M, Kanaan M, Kremer H, Pennings RJ Tags: Hear Res Source Type: research

Voice Emotion Perception and Production in Cochlear Implant Users.
Abstract Voice emotion is a fundamental component of human social interaction and social development. Unfortunately, cochlear implant users are often forced to interface with highly degraded prosodic cues as a result of device constraints in extraction, processing, and transmission. As such, individuals with cochlear implants frequently demonstrate significant difficulty in recognizing voice emotions in comparison to their normal hearing counterparts. Cochlear implant-mediated perception and production of voice emotion is an important but relatively understudied area of research. However, a rich understanding of t...
Source: Hearing Research - January 10, 2017 Category: Audiology Authors: Jiam NT, Caldwell M, Deroche ML, Chatterjee M, Limb CJ Tags: Hear Res Source Type: research

Estimation of the Young's modulus of the human pars tensa using in-situ pressurization and inverse finite-element analysis.
Abstract Finite-element models of the tympanic membrane are sensitive to the Young's modulus of the pars tensa. The aim of this work is to estimate the Young's modulus under a different experimental paradigm than currently used on the human tympanic membrane. These additional values could potentially be used by the auditory biomechanics community for building consensus. The Young's modulus of the human pars tensa was estimated through inverse finite-element modelling of an in-situ pressurization experiment. The experiments were performed on three specimens with a custom-built pressurization unit at a quasi-static ...
Source: Hearing Research - January 9, 2017 Category: Audiology Authors: Rohani SA, Ghomashchi S, Agrawal SK, Ladak HM Tags: Hear Res Source Type: research

The path of a click stimulus from ear canal to umbo.
Abstract The tympanic membrane (TM) has a key role in transmitting sounds to the inner ear, but a concise description of how the TM performs this function remains elusive. This paper probes TM operation by applying a free field click stimulus to the gerbil ear and exploring the consequent motions of the TM and umbo. Motions of the TM were measured both on radial tracks starting close to the umbo and on a grid distal and adjacent to the umbo. The experimental results confirmed the high fidelity of sound transmission from the ear canal to the umbo. A delay of 5-15 μs was seen in the onset of TM motion between poi...
Source: Hearing Research - January 9, 2017 Category: Audiology Authors: Milazzo M, Fallah E, Carapezza M, Kumar NS, Lei JH, Olson ES Tags: Hear Res Source Type: research

Culture media-based selection of endothelial cells, pericytes, and perivascular-resident macrophage-like melanocytes from the young mouse vestibular system.
Abstract The vestibular blood-labyrinth barrier (BLB) is comprised of perivascular-resident macrophage-like melanocytes (PVM/Ms) and pericytes (PCs), in addition to endothelial cells (ECs) and basement membrane (BM), and bears strong resemblance to the cochlear BLB in the stria vascularis. Over the past few decades, in vitro cell-based models have been widely used in blood-brain barrier (BBB) and blood-retina barrier (BRB) research, and have proved to be powerful tools for studying cell-cell interactions in their respective organs. Study of both the vestibular and strial BLB has been limited by the unavailability ...
Source: Hearing Research - January 9, 2017 Category: Audiology Authors: Zhang J, Chen S, Cai J, Hou Z, Wang X, Kachelmeier A, Shi X Tags: Hear Res Source Type: research

Degeneration of auditory nerve fibers in guinea pigs with severe sensorineural hearing loss.
In conclusion, the data strongly suggest that each surviving SGC possesses an axon. PMID: 28087418 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - January 9, 2017 Category: Audiology Authors: Kroon S, Ramekers D, Smeets EM, Hendriksen FG, Klis SF, Versnel H Tags: Hear Res Source Type: research

Cochlear synaptopathy in acquired sensorineural hearing loss: Manifestations and mechanisms.
Abstract Common causes of hearing loss in humans - exposure to loud noise or ototoxic drugs and aging - often damage sensory hair cells, reflected as elevated thresholds on the clinical audiogram. Recent studies in animal models suggest, however, that well before this overt hearing loss can be seen, a more insidious, but likely more common, process is taking place that permanently interrupts synaptic communication between sensory inner hair cells and subsets of cochlear nerve fibers. The silencing of affected neurons alters auditory information processing, whether accompanied by threshold elevations or not, and is...
Source: Hearing Research - January 9, 2017 Category: Audiology Authors: Liberman MC, Kujawa SG Tags: Hear Res Source Type: research

Engineering out the Noise.
Abstract The US Navy, through an Office of Naval Research (ONR) lead effort on Noise Induced Hearing Loss (NIHL), is investigating methods and techniques to mitigate hearing loss for the crews and warfighters. Hearing protection is a viable and increasingly popular method of reducing hearing exposure for many ship crewmembers; however, it has limitations on comfort and low frequency effectiveness. Furthermore, Personal Hearing Protection (PHP) is often used improperly. Proper vessel planning, programmatic changes and advances in noise control engineering can also have significant impacts by inherently reducing noi...
Source: Hearing Research - January 6, 2017 Category: Audiology Authors: Yankaskas K, Fischer R, Spence J, Komrower J Tags: Hear Res Source Type: research

Translational issues in cochlear synaptopathy.
Abstract Understanding the biology of the previously underappreciated sensitivity of cochlear synapses to noise insult, and its clinical consequences, is becoming a mission for a growing number of auditory researchers. In addition, several research groups have become interested in developing therapeutic approaches that can reverse synaptopathy and restore hearing function. One of the major challenges to realizing the potential of synaptopathy rodent models is that current clinical audiometric approaches cannot yet reveal the presence of this subtle cochlear pathology in humans. This has catalyzed efforts, both fro...
Source: Hearing Research - January 5, 2017 Category: Audiology Authors: Hickox AE, Larsen E, Heinz MG, Shinobu L, Whitton JP Tags: Hear Res Source Type: research

Genetic perturbations suggest a role of the resting potential in regulating the expression of the ion channels of the KCNA and HCN families in octopus cells of the ventral cochlear nucleus.
We report five new findings: First, the magnitude of gh and gKL varied over more than two-fold between wild type strains of mice. Second, average resting potentials are not different in different strains of mice even in the face of large differences in average gKL and gh. Third, IKL has two components, one being α-dendrotoxin (α-DTX)-sensitive and partially inactivating and the other being α-DTX-insensitive, tetraethylammonium (TEA)-sensitive, and non-inactivating. Fourth, the loss of Kv1.1 results in diminution of the α-DTX-sensitive IKL, and compensatory increased expression of an α-DTX-inse...
Source: Hearing Research - January 4, 2017 Category: Audiology Authors: Cao XJ, Oertel D Tags: Hear Res Source Type: research

Contralateral electrically-evoked suppression of transient evoked otoacoustic emissions in single-sided deaf patients.
PMID: 28057487 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - January 1, 2017 Category: Audiology Authors: Dziemba OC, Grafmans D, Merz S, Hocke T Tags: Hear Res Source Type: research

Simultaneously-evoked Auditory Potentials (SEAP): a new method for concurrent measurement of cortical and subcortical auditory-evoked activity.
Abstract Recent electrophysiological work has evinced a capacity for plasticity in subcortical auditory nuclei in human listeners. Similar plastic effects have been measured in cortically-generated auditory potentials but it is unclear how the two interact. Here we present Simultaneously-Evoked Auditory Potentials (SEAP), a method designed to concurrently elicit electrophysiological brain potentials from inferior colliculus, thalamus, and primary and secondary auditory cortices. Twenty-six normal-hearing adult subjects (mean 19.26 years, 9 male) were exposed to 2400 monaural (right-ear) presentations of a speciall...
Source: Hearing Research - December 29, 2016 Category: Audiology Authors: Slugocki C, Bosnyak D, Trainor LJ Tags: Hear Res Source Type: research

Cochlear hair cell regeneration after noise-induced hearing loss: Does regeneration follow development?
Abstract Noise-induced hearing loss (NIHL) affects a large number of military personnel and civilians. Regenerating inner-ear cochlear hair cells (HCs) is a promising strategy to restore hearing after NIHL. In this review, we first summarize recent transcriptome profile analysis of zebrafish lateral lines and chick utricles where spontaneous HC regeneration occurs after HC damage. We then discuss recent studies in other mammalian regenerative systems such as pancreas, heart and central nervous system. Both spontaneous and forced HC regeneration occurs in mammalian cochleae in vivo involving proliferation and direc...
Source: Hearing Research - December 25, 2016 Category: Audiology Authors: Zheng F, Zuo J Tags: Hear Res Source Type: research

Adenosine receptors regulate susceptibility to noise-induced neural injury in the mouse cochlea and hearing loss.
Abstract Our previous studies have shown that the stimulation of A1 adenosine receptors in the inner ear can mitigate the loss of sensory hair cells and hearing loss caused by exposure to traumatic noise. Here, we focus on the role of adenosine receptors (AR) in the development of noise-induced neural injury in the cochlea using A1AR and A2AAR null mice (A1AR(-/-) and A2AAR(-/-)). Wildtype (WT) and AR deficient mice were exposed to octave band noise (8-16 kHz, 100 dB SPL) for 2 hours to induce cochlear injury and hearing loss. Auditory thresholds and input/output functions were assessed using auditory brainstem re...
Source: Hearing Research - December 25, 2016 Category: Audiology Authors: Vlajkovic SM, Ambepitiya K, Barclay M, Boison D, Housley GD, Thorne PR Tags: Hear Res Source Type: research

Examining the short term effects of emotion under an Adaptation Level Theory Model of Tinnitus Perception.
CONCLUSIONS: The results indicate that the negative valence dimension of emotion is associated with increased tinnitus magnitude judgements and gender effects may also be present, but only when the emotional stimulus is in the auditory modality. Sounds with emotional associations may be used for sound therapy for tinnitus relief; it is of interest to determine whether the emotional component of sound treatments can play a role in reversing the negative responses discussed in this paper. PMID: 28027920 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - December 23, 2016 Category: Audiology Authors: Durai M, O'Keeffe MG, Searchfield GD Tags: Hear Res Source Type: research

Impaired auditory processing and altered structure of the endbulb of Held synapse in mice lacking the GluA3 subunit of AMPA receptors.
K, Rubio ME Abstract AMPA glutamate receptor complexes with fast kinetics conferred by subunits like GluA3 and GluA4 are essential for temporal precision of synaptic transmission. The specific role of GluA3 in auditory processing and experience related changes in the auditory brainstem remain unknown. We investigated the role of the GluA3 in auditory processing by using wild type (WT) and GluA3 knockout (GluA3-KO) mice. We recorded auditory brainstem responses (ABR) to assess auditory function and used electron microscopy to evaluate the ultrastructure of the auditory nerve synapse on bushy cells (AN-BC synapse). ...
Source: Hearing Research - December 19, 2016 Category: Audiology Authors: García-Hernández S, Abe M, Sakimura K, Rubio ME Tags: Hear Res Source Type: research

Multiscale Mapping of Frequency Sweep Rate in Mouse Auditory Cortex.
Abstract Functional organization is a key feature of the neocortex that often guides studies of sensory processing, development, and plasticity. Tonotopy, which arises from the transduction properties of the cochlea, is the most widely studied organizational feature in auditory cortex; however, in order to process complex sounds, cortical regions are likely specialized for higher order features. Here, motivated by the prevalence of frequency modulations in mouse ultrasonic vocalizations and aided by the use of a multiscale imaging approach, we uncover a functional organization across the extent of auditory cortex ...
Source: Hearing Research - December 19, 2016 Category: Audiology Authors: Issa JB, Haeffele BD, Young ED, Yue DT Tags: Hear Res Source Type: research

The mammalian Cretaceous cochlear revolution.
Abstract The hearing organs of amniote vertebrates show large differences in their size and structure between the species' groups. In spite of this, their performance in terms of hearing sensitivity and the frequency selectivity of auditory-nerve units shows unexpectedly small differences. The only substantial difference is that therian, defined as live-bearing, mammalian groups are able to hear ultrasonic frequencies (above 15 to 20 kHz), whereas in contrast monotreme (egg laying) mammals and all non-mammalian amniotes cannot. This review compares the structure and physiology of the cochleae of the main groups an...
Source: Hearing Research - December 18, 2016 Category: Audiology Authors: Manley GA Tags: Hear Res Source Type: research

Noise-induced cochlear synaptopathy: Past findings and future studies.
Abstract For decades, we have presumed the death of hair cells and spiral ganglion neurons are the main cause of hearing loss and difficulties understanding speech in noise, but new findings suggest synapse loss may be the key contributor. Specifically, recent preclinical studies suggest that the synapses between inner hair cells and spiral ganglion neurons with low spontaneous rates and high thresholds are the most vulnerable subcellular structures, with respect to insults during aging and noise exposure. This cochlear synaptopathy can be "hidden" because this synaptic loss can occur without permanent h...
Source: Hearing Research - December 18, 2016 Category: Audiology Authors: Kobel M, Le Prell CG, Liu J, Hawks JW, Bao J Tags: Hear Res Source Type: research

Evidence of "hidden hearing loss" following noise exposures that produce robust TTS and ABR wave-I amplitude reductions.
Evidence of "hidden hearing loss" following noise exposures that produce robust TTS and ABR wave-I amplitude reductions. Hear Res. 2016 Dec 18;: Authors: Lobarinas E, Spankovich C, Le Prell CG Abstract In animals, noise exposures that produce robust temporary threshold shifts (TTS) can produce immediate damage to afferent synapses and long-term degeneration of low spontaneous rate auditory nerve fibers. This synaptopathic damage has been shown to correlate with reduced auditory brainstem response (ABR) wave-I amplitudes at suprathreshold levels. The perceptual consequences of this "syna...
Source: Hearing Research - December 17, 2016 Category: Audiology Authors: Lobarinas E, Spankovich C, Le Prell CG Tags: Hear Res Source Type: research

Mechanical Model of an Arched Basilar Membrane in the Gerbil Cochlea.
Abstract The frequency selectivity of a gerbil cochlea, unlike other mammals, does not depend on varying thickness and width of its basilar membrane from the basal to the apical end. We model the gerbil arched basilar membrane focusing on the radial tension, embedded fiber thickness, and the membrane arch, which replace the functionality of the variation in thickness and width. The model is verified with the previous gerbil cochlea model which estimated the equivalent basilar membrane thickness and shown to be more accurate than the flat sandwiched basilar membrane model. The simple sinusoidal-shaped bending mode ...
Source: Hearing Research - December 12, 2016 Category: Audiology Authors: Chan WX, Lee SH, Kim N, Shin CS, Yoon YJ Tags: Hear Res Source Type: research

Musicianship enhances ipsilateral and contralateral efferent gain control to the cochlea.
Abstract Human hearing sensitivity is easily compromised with overexposure to excessively loud sounds, leading to permanent hearing damage. Consequently, finding activities and/or experiential factors that distinguish "tender" from "tough" ears (i.e., acoustic vulnerability) would be important for identifying people at higher risk for hearing damage. To regulate sound transmission and protect the inner ear against acoustic trauma, the auditory system modulates gain control to the cochlea via biological feedback of the medial olivocochlear (MOC) efferents, a neuronal pathway linking the lower br...
Source: Hearing Research - December 9, 2016 Category: Audiology Authors: Bidelman GM, Schneider AD, Heitzmann VR, Bhagat SP Tags: Hear Res Source Type: research

Tinnitus with a normal audiogram: Relation to noise exposure but no evidence for cochlear synaptopathy.
Abstract In rodents, exposure to high-level noise can destroy synapses between inner hair cells and auditory nerve fibers, without causing hair cell loss or permanent threshold elevation. Such "cochlear synaptopathy" is associated with amplitude reductions in wave I of the auditory brainstem response (ABR) at moderate-to-high sound levels. Similar ABR results have been reported in humans with tinnitus and normal audiometric thresholds, leading to the suggestion that tinnitus in these cases might be a consequence of synaptopathy. However, the ABR is an indirect measure of synaptopathy and it is unclear wh...
Source: Hearing Research - December 9, 2016 Category: Audiology Authors: Guest H, Munro KJ, Prendergast G, Howe S, Plack CJ Tags: Hear Res Source Type: research

Correlation between the frequency difference limen and an index based on principal component analysis of the frequency-following response of normal hearing listeners.
In this study, we examined the brain-behavior relationship between frequency-following responses (FFRs) evoked by pure/sweeping tones and frequency difference limens (FDLs). FFRs are considered to reflect subcortical phase locking, and FDLs are a psychophysical measure of behavioral performance in pitch discrimination. Traditional measures of FFR strength were found to be poorly correlated with FDL. Here, we introduced principal component analysis into FFR analysis and extracted an FFR component that was correlated with individual pitch discrimination. The absolute value of the score of this FFR principal component (but no...
Source: Hearing Research - December 8, 2016 Category: Audiology Authors: Zhang X, Gong Q Tags: Hear Res Source Type: research

Loudness and Pitch Perception using Dynamically Compensated Virtual Channels.
r A Abstract Reducing power consumption is important for the development of smaller cochlear implant (CI) speech processors. Simultaneous electrode stimulation may improve power efficiency by minimizing the required current applied to a given electrode. Simultaneous in-phase stimulation on adjacent electrodes (i.e. virtual channels) can be used to elicit pitch percepts intermediate to the ones provided by each of the physical electrodes in isolation. Virtual channels are typically implemented in monopolar stimulation mode, producing broad excitation patterns. Focused stimulation may reduce the excitation patterns,...
Source: Hearing Research - December 6, 2016 Category: Audiology Authors: Nogueira W, Litvak L, Landsberger DM, Büchner A Tags: Hear Res Source Type: research

Sequential stream segregation of voiced and unvoiced speech sounds based on fundamental frequency.
This study measured listeners' ability to integrate or segregate sequences of consonant-vowel tokens, comprising a voiceless fricative and a vowel, as a function of the F0 difference between interleaved sequences of tokens. A performance-based measure was used, in which listeners detected the presence of a repeated token either within one sequence or between the two sequences (measures of voluntary and obligatory streaming, respectively). The results showed a systematic increase of voluntary stream segregation as the F0 difference between the two interleaved sequences increased from 0 to 13 semitones, suggesting that F0 di...
Source: Hearing Research - December 2, 2016 Category: Audiology Authors: David M, Lavandier M, Grimault N, Oxenham AJ Tags: Hear Res Source Type: research

Cellular mechanisms of noise-induced hearing loss.
Abstract Exposure to intense sound or noise can result in purely temporary threshold shift (TTS), or leave a residual permanent threshold shift (PTS) along with alterations in growth functions of auditory nerve output. Recent research has revealed a number of mechanisms that contribute to noise-induced hearing loss (NIHL). The principle cause of NIHL is damage to cochlear hair cells and associated synaptopathy. Contributions to TTS include reversible damage to hair cell (HC) stereocilia or synapses, while moderate TTS reflects protective purinergic hearing adaptation. PTS represents permanent damage to or loss of ...
Source: Hearing Research - November 30, 2016 Category: Audiology Authors: Kurabi A, Keithley EM, Housley GD, Ryan AF, Wong AC Tags: Hear Res Source Type: research

Effects of model definitions and parameter values in finite element modeling of human middle ear mechanics.
CONCLUSION: The presented results provide insights into the importance of different features in middle ear finite element modeling. The application of three different individual middle ear geometries in a single study reduces the possibility that the conclusions are strongly affected by geometrical abnormalities. Some modeling variations that were hypothesized to be influential turned out to be of minor importance. Furthermore, it could be confirmed that different geometries, simulated using the same parameters and definitions, can produce significantly different responses. PMID: 27915026 [PubMed - as supplied by publ...
Source: Hearing Research - November 29, 2016 Category: Audiology Authors: De Greef D, Pires F, Dirckx JJ Tags: Hear Res Source Type: research

Tonotopic representation of loudness in the human cortex.
Abstract A prominent feature of the auditory system is that neurons show tuning to audio frequency; each neuron has a characteristic frequency (CF) to which it is most sensitive. Furthermore, there is an orderly mapping of CF to position, which is called tonotopic organization and which is observed at many levels of the auditory system. In a previous study (Thwaites et al., 2016) we examined cortical entrainment to two auditory transforms predicted by a model of loudness, instantaneous loudness and short-term loudness, using speech as the input signal. The model is based on the assumption that neural activity is c...
Source: Hearing Research - November 29, 2016 Category: Audiology Authors: Thwaites A, Schlittenlacher J, Nimmo-Smith I, Marslen-Wilson WD, Moore BC Tags: Hear Res Source Type: research

Audiologic characteristics in a sample of recently-separated military Veterans: The Noise Outcomes in Servicemembers Epidemiology Study (NOISE Study).
Abstract Military Service Members are often exposed to high levels of occupational noise, solvents, and other exposures that can be damaging to the auditory system. Little is known about hearing loss and how it progresses in Veterans following military service. This epidemiology study is designed to evaluate and monitor a cohort of Veterans for 20 years or more to determine how hearing loss changes over time and how those changes are related to noise exposure and other ototoxic exposures encountered during military service. Data reported here are from baseline assessments of the first 100 study participants (84 ma...
Source: Hearing Research - November 28, 2016 Category: Audiology Authors: Gordon JS, Griest SE, Thielman EJ, Carlson KC, Helt WJ, Lewis MS, Blankenship C, Austin D, Theodoroff SM, Henry JA Tags: Hear Res Source Type: research

Speech enhancement based on neural networks improves speech intelligibility in noise for cochlear implant users.
Abstract Speech understanding in noisy environments is still one of the major challenges for cochlear implant (CI) users in everyday life. We evaluated a speech enhancement algorithm based on neural networks (NNSE) for improving speech intelligibility in noise for CI users. The algorithm decomposes the noisy speech signal into time-frequency units, extracts a set of auditory-inspired features and feeds them to the neural network to produce an estimation of which frequency channels contain more perceptually important information (higher signal-to-noise ratio, SNR). This estimate is used to attenuate noise-dominated...
Source: Hearing Research - November 28, 2016 Category: Audiology Authors: Goehring T, Bolner F, Monaghan JJ, van Dijk B, Zarowski A, Bleeck S Tags: Hear Res Source Type: research

Time course of organ of Corti degeneration after noise exposure.
Abstract From our permanent collection of plastic-embedded flat preparations of chinchilla cochleae, 22 controls and 199 ears from noise-exposed animals were used to determine when, postexposure, hair cell (HC) and supporting cell (SC) degeneration were completed. The exposed ears were divided into four groups based on exposure parameters: 0.5- or 4-kHz octave band of noise at moderate (M) or high (H) intensities. Postexposure survival ranged from
Source: Hearing Research - November 23, 2016 Category: Audiology Authors: Bohne BA, Kimlinger M, Harding GW Tags: Hear Res Source Type: research

Evidence that hidden hearing loss underlies amplitude modulation encoding deficits in individuals with and without tinnitus.
Abstract Damage to auditory nerve fibers that expresses with suprathreshold sounds but is hidden from the audiogram has been proposed to underlie deficits in temporal coding ability observed among individuals with otherwise normal hearing, and to be present in individuals experiencing chronic tinnitus with clinically normal audiograms. We tested whether these individuals may have hidden synaptic losses on auditory nerve fibers with low spontaneous rates of firing (low-SR fibers) that are important for coding suprathreshold sounds in noise while high-SR fibers determining threshold responses in quiet remain relativ...
Source: Hearing Research - November 21, 2016 Category: Audiology Authors: Paul BT, Bruce IC, Roberts LE Tags: Hear Res Source Type: research

Noise dosimetry for tactical environments.
Abstract Noise exposure and the subsequent hearing loss are well documented aspects of military life. Numerous studies have indicated high rates of noise-induced hearing injury (NIHI) in active-duty service men and women, and recent statistics from the US Department of Veterans Affairs indicate a population of veterans with hearing loss that is growing at an increasing rate. In an effort to minimize hearing loss, the US Department of Defense (DoD) updated its Hearing Conservation Program in 2010, and also has recently revised the DoD Design Criteria Standard Noise Limits (MIL-STD-1474E) which defines allowable noi...
Source: Hearing Research - November 18, 2016 Category: Audiology Authors: Smalt CJ, Lacirignola J, Davis S, Calamia PT, Collins P Tags: Hear Res Source Type: research

Individual differences in speech-in-noise perception parallel neural speech processing and attention in preschoolers.
Abstract From bustling classrooms to unruly lunchrooms, school settings are noisy. To learn effectively in the unwelcome company of numerous distractions, children must clearly perceive speech in noise. In older children and adults, speech-in-noise perception is supported by sensory and cognitive processes, but the correlates underlying this critical listening skill in young children (3-5 year olds) remain undetermined. Employing a longitudinal design (two evaluations separated by ∼12 months), we followed a cohort of 59 preschoolers, ages 3.0-4.9, assessing word-in-noise perception, cognitive abilities (intell...
Source: Hearing Research - November 14, 2016 Category: Audiology Authors: Thompson EC, Woodruff Carr K, White-Schwoch T, Otto-Meyer S, Kraus N Tags: Hear Res Source Type: research

A review of the progress and pitfalls of FDA policy process: Planning a pathway for pharmaceutical interventions for hearing loss development.
Abstract The Federal Food and Drug Administration, or FDA is generally considered a powerful gatekeeper, able to deliver or withhold life-saving cures and create or destroy economic windfalls. As the decades go by, and technologies, diseases, public health demands, and politics evolve, we can identify patterns of change, action and inter-action among some of these traditional stakeholders in the FDA's policy sphere. A careful examination of this agency's colorful history can shed light on central features of the agency's policy process, which has been quite receptive to its stakeholders and adaptive to change over...
Source: Hearing Research - November 11, 2016 Category: Audiology Authors: Hammill T Tags: Hear Res Source Type: research