Noise-induced changes in expression levels of NADPH oxidases in the cochlea.
Conclusion: Noise-induced up-regulation of NOX1 and DUOX2 could be linked to cochlear injury. In contrast, down-regulation of NOX3 may represent an endogenous protective mechanism to reduce oxidative stress in the noise-exposed cochlea. Inhibition of NADPH oxidases is potentially a novel pathway for therapeutic management of noise-induced hearing loss. PMID: 23899412 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 27, 2013 Category: Audiology Authors: Vlajkovic SM, Lin SC, Yan Wong AC, Wackrow B, Thorne PR Tags: Hear Res Source Type: research

Gentamicin administration on the stapes footplate causes greater hearing loss and vestibulotoxicity than round window administration in guinea pigs.
Abstract Clinically, gentamicin has been used extensively to treat the debilitating symptoms of Mèniére's disease and is well known for its vestibulotoxic properties. Until recently, it was widely accepted that the round window membrane (RWM) was the primary entry route into the inner ear following intratympanic drug administration. In the current study, gentamicin was delivered to either the RWM or the stapes footplate of guinea pigs (GPs) to assess the associated hearing loss and histopathology associated with each procedure. Vestibulotoxicity of the utricular macula, saccular macula, and crista am...
Source: Hearing Research - July 27, 2013 Category: Audiology Authors: King EB, Salt AN, Kel GE, Eastwood HT, O'Leary SJ Tags: Hear Res Source Type: research

Using resting state functional connectivity to unravel networks of tinnitus.
Abstract Resting state functional connectivity (rs-fc) using fMRI has become an important tool in examining differences in brain activity between patient and healthy populations. Studies employing rs-fc have successfully identified altered intrinsic neural networks in many neurological and psychiatric disorders, including Alzheimer's disease, schizophrenia, and more recently, tinnitus. The neural mechanisms of subjective tinnitus, defined as the perception of sound without an external source, are not well understood. Several inherent networks have been implicated in tinnitus; these include default mode, auditory, ...
Source: Hearing Research - July 26, 2013 Category: Audiology Authors: Husain FT, Schmidt SA Tags: Hear Res Source Type: research

Coding of Vocalizations by Single Neurons in Ventrolateral Prefrontal Cortex.
In this study we therefore examined the role of VLPFC in encoding vocalization call type information. Specifically, we examined previously recorded single unit responses from the VLPFC in awake, behaving rhesus macaques in response to 3 types of species-specific vocalizations made by 3 individual callers. Analysis of responses by vocalization call type and caller identity showed that ∼ 19 % of cells had a main effect of call type with fewer cells encoding caller. Classification performance of VLPFC neurons was ∼ 42% averaged across the population. When assessed at discrete time bins, classification performance reac...
Source: Hearing Research - July 26, 2013 Category: Audiology Authors: Plakke B, Diltz MD, Romanski LM Tags: Hear Res Source Type: research

Synchronisation signatures in the listening brain: A perspective from non-invasive neuroelectrophysiology.
We present (1) a more general introduction on how to study local as well as interareal synchronisation in human M/EEG; (2) how these networks may subserve and influence illusory auditory perception (clinical and non-clinical) and (3) auditory selective attention; and (4) how oscillatory networks further reflect and impact on speech comprehension. PMID: 23895875 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 26, 2013 Category: Audiology Authors: Weisz N, Obleser J Tags: Hear Res Source Type: research

Psychophysics and neuronal bases of sound localization in humans.
This article is part of a Special Issue entitled . PMID: 23886698 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 22, 2013 Category: Audiology Authors: Ahveninen J, Kopco N, Jääskeläinen IP Tags: Hear Res Source Type: research

Some characteristics of amplified music through hearing aids.
Abstract Hearing aids are a relatively non-invasive means of reducing the negative effects of hearing loss on an individual who does not require a cochlear implant. Music amplified through hearing aids has some interesting characteristics but high fidelity is not typically one of them. This poses a serious problem for the investigator who wants to perform research on music with hearing impaired individuals who wear hearing aids. If the signal at the tympanic membrane is somewhat distorted then this has consequences for the assessment of music processing when examining both the peripheral and the central auditory s...
Source: Hearing Research - July 20, 2013 Category: Audiology Authors: Chasin M, Hockley NS Tags: Hear Res Source Type: research

The efficiency of design-based stereology in estimating spiral ganglion populations in mice.
Abstract Accurate quantification of cell populations is essential in assessing and evaluating neural survival and degeneration in experimental groups. Estimates obtained through traditional two-dimensional counting methods are heavily biased by the counting parameters in relation to the size and shape of the neurons to be counted, resulting in a large range of inaccurate counts. In contrast, counting every cell in a population can be extremely labor-intensive. The present study hypothesizes that design-based stereology provides estimates of the total number of cochlear spiral ganglion neurons (SGNs) in mice that a...
Source: Hearing Research - July 19, 2013 Category: Audiology Authors: Schettino AE, Lauer AM Tags: Hear Res Source Type: research

Cytodifferentiation of hair cells during the development of a basal chordate.
Abstract Tunicates are unic animals for studying the origin and evolution of vertebrates because they are considered vertebrates' closest living relatives and share the vertebrate body plan and many specific features. Both possess neural placodes, transient thickenings of the cranial ectoderm that give rise to various types of sensory cells, including axonless secondary mechanoreceptors. In vertebrates, these are represented by the hair cells of the inner ear and the lateral line, which have an apical apparatus typically bearing cilia and stereovilli. In tunicates, they are found in the coronal organ, which is a m...
Source: Hearing Research - July 19, 2013 Category: Audiology Authors: Gasparini F, Caicci F, Rigon F, Zaniolo G, Burighel P, Manni L Tags: Hear Res Source Type: research

Auditory filter width affects response magnitude but not frequency specificity in auditory cortex.
Abstract Spectral analysis of acoustic stimuli occurs in the auditory periphery (termed frequency selectivity) as well as at the level of auditory cortex (termed frequency specificity). Frequency selectivity is commonly investigated using an auditory filter model, while frequency specificity is often investigated as neural adaptation of the N1 response in electroencephalography (EEG). However, the effects of aging on frequency-specific adaptation, and the link between peripheral frequency selectivity and neural frequency specificity have not received much attention. Here, normal hearing younger (20-31 years) and o...
Source: Hearing Research - July 19, 2013 Category: Audiology Authors: Herrmann B, Henry MJ, Scharinger M, Obleser J Tags: Hear Res Source Type: research

A quantitative morphological analysis of the inner ear of galliform birds.
In this study, we examine the morphology of the inner ear and use this relationship to predict the hearing range and sensitivities of species within the Order Galliformes (chicken, quail and allies). All galliforms share a similar inner ear morphology, which is characterized by gradients in hair cell morphology that are similar to other birds. Most galliforms did have an area of morphologically similar hair cells at the apical end of the BP, indicative of a low frequency specialization. We suggest that, in general, the galliform inner ear is tuned for detecting low frequencies, with most hair cells and more than half of th...
Source: Hearing Research - July 17, 2013 Category: Audiology Authors: Corfield JR, Krilow JM, Vande Ligt MN, Iwaniuk AN Tags: Hear Res Source Type: research

Look now and hear what's coming: on the functional role of cross-modal phase reset.
Abstract In our multisensory environment our sensory systems are continuously receiving information that is often interrelated and must be integrated. Recent work in animals and humans has demonstrated that input to one sensory modality can reset the phase of ambient cortical oscillatory activity in another. The periodic fluctuations in neuronal excitability reflected in these oscillations can thereby be aligned to forthcoming anticipated sensory input. In the auditory domain, the example par excellence is speech, because of its inherently rhythmic structure. In contrast, fluctuations of oscillatory phase in the v...
Source: Hearing Research - July 12, 2013 Category: Audiology Authors: Thorne JD, Debener S Tags: Hear Res Source Type: research

Lithium Alters the Morphology of Neurites Regenerating from Cultured Adult Spiral Ganglion Neurons.
Abstract The small-molecule drug lithium (as a monovalent ion) promotes neurite regeneration and functional recovery, is easy to administer, and is approved for human use to treat bipolar disorder. Lithium exerts its neuritogenic effect mainly by inhibiting glycogen synthase kinase 3, a constitutively-active serine/threonine kinase that is regulated by neurotrophin and "wingless-related MMTV integration site" (Wnt) signaling. In spiral ganglion neurons of the cochlea, the effects of lithium and the function of glycogen synthase kinase 3 have not been investigated. We, therefore, set out to test whether l...
Source: Hearing Research - July 12, 2013 Category: Audiology Authors: Shah SM, Patel CH, Feng AS, Kollmar R Tags: Hear Res Source Type: research

Using neuroimaging to understand the cortical mechanisms of auditory selective attention.
This article is part of a Special Issue entitled . PMID: 23850664 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 9, 2013 Category: Audiology Authors: Lee AK, Larson E, Maddox RK, Shinn-Cunningham BG Tags: Hear Res Source Type: research

Regeneration of mammalian cochlear and vestibular hair cells through Hes1/Hes5 modulation with siRNA.
Abstract The Notch pathway is a cell signaling pathway determining initial specification and subsequent cell fate in the inner ear. Previous studies have suggested that new hair cells (HCs) can be regenerated in the inner ear by manipulating the Notch pathway. In the present study, delivery of siRNA to Hes1 and Hes5 using a transfection reagent or siRNA to Hes1 encapsulated within poly(lactide-co-glycolide acid) (PLGA) nanoparticles increased HC numbers in non-toxin treated organotypic cultures of cochleae and maculae of postnatal day 3 mouse pups. An increase in HCs was also observed in cultured cochleae and macu...
Source: Hearing Research - July 9, 2013 Category: Audiology Authors: Du X, Li W, Gao X, West MB, Mark Saltzman W, Cheng CJ, Stewart C, Zheng J, Cheng W, Kopke RD Tags: Hear Res Source Type: research

Turning Down the Noise: The Benefit of Musical Training on the Aging Auditory Brain.
Abstract Age-related decline in hearing abilities is a ubiquitous part of aging, and commonly impacts speech understanding, especially when there are competing sound sources. While such age effects are partially due to changes within the cochlea, difficulties typically exist beyond measurable hearing loss, suggesting that central brain processes, as opposed to simple peripheral mechanisms (e.g., hearing sensitivity), play a critical role in governing hearing abilities late into life. Current training regimens aimed to improve central auditory processing abilities have experienced limited success in promoting liste...
Source: Hearing Research - July 2, 2013 Category: Audiology Authors: Alain C, Zendel BR, Hutka S, Bidelman GM Tags: Hear Res Source Type: research

Brain Dynamics Encode the Spectrotemporal Boundaries of Auditory Objects.
Abstract Perception of objects in the scene around us is effortless and intuitive, yet entails profound computational challenges. Progress has been made in understanding some mechanisms by which the brain encodes the boundaries and surfaces of visual objects. However, in the auditory domain, these mechanisms are poorly understood. We investigated differences between neural responses to spectrotemporal boundaries in the auditory scene. We used iterated rippled noise to create perceptual boundaries with and without energy transients. In contrast to boundaries marked by energy transients, second-order boundaries were...
Source: Hearing Research - July 2, 2013 Category: Audiology Authors: McMullan AR, Hambrook DA, Tata MS Tags: Hear Res Source Type: research

Auditory Signal Processing in Communication: Perception and Performance of Vocal Sounds.
Abstract Learning and maintaining the sounds we use in vocal communication require accurate perception of the sounds we hear performed by others and feedback-dependent imitation of those sounds to produce our own vocalizations. Understanding how the central nervous system integrates auditory and vocal-motor information to enable communication is a fundamental goal of systems neuroscience, and insights into the mechanisms of those processes will profoundly enhance clinical therapies for communication disorders. Gaining the high-resolution insight necessary to define the circuits and cellular mechanisms underlying h...
Source: Hearing Research - July 1, 2013 Category: Audiology Authors: Prather JF Tags: Hear Res Source Type: research

Simultaneous 3D imaging of sound-induced motions of the tympanic membrane and middle ear ossicles.
Yun SH Abstract Efficient transfer of sound by the middle ear ossicles is essential for hearing. Various pathologies can impede the transmission of sound and thereby cause conductive hearing loss. Differential diagnosis of ossicular disorders can be challenging since the ossicles are normally hidden behind the tympanic membrane (TM). Here we describe the use of a technique termed optical coherence tomography (OCT) vibrography to view the sound-induced motion of the TM and ossicles simultaneously. With this method, we were able to capture three-dimensional motion of the intact TM and ossicles of the chinchilla ear...
Source: Hearing Research - June 27, 2013 Category: Audiology Authors: Chang EW, Cheng JT, Röösli C, Kobler JB, Rosowski JJ, Yun SH Tags: Hear Res Source Type: research

Representation of speech in human auditory cortex: Is it special?
Abstract Successful categorization of phonemes in speech requires that the brain analyze the acoustic signal along both spectral and temporal dimensions. Neural encoding of the stimulus amplitude envelope is critical for parsing the speech stream into syllabic units. Encoding of voice onset time (VOT) and place of articulation (POA), cues necessary for determining phonemic identity, occurs within shorter time frames. An unresolved question is whether the neural representation of speech is based on processing mechanisms that are unique to humans and shaped by learning and experience, or is based on rules governing ...
Source: Hearing Research - June 18, 2013 Category: Audiology Authors: Steinschneider M, Nourski KV, Fishman YI Tags: Hear Res Source Type: research

Processing of communication sounds: Contributions of learning, memory, and experience.
This article is part of a Special Issue entitled "Vocalizations and Hearing". PMID: 23792078 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 18, 2013 Category: Audiology Authors: Poremba A, Bigelow J, Rossi B Tags: Hear Res Source Type: research

Influence of inter-field communication on neuronal response synchrony across auditory cortex.
Abstract Sensory information is encoded by cortical neurons in the form of synaptic discharge time and rate level. These neuronal codes generate response patterns across cell assemblies that are crucial to various cognitive functions. Despite pivotal information about structural and cognitive factors involved in the generation of synchronous neuronal responses such as stimulus context, attention, age, cortical depth, sensory experience, and receptive field properties, the influence of cortico-cortical connectivity on the emergence of neuronal response patterns is poorly understood. The present investigation assess...
Source: Hearing Research - June 18, 2013 Category: Audiology Authors: Carrasco A, Lomber SG Tags: Hear Res Source Type: research

Prophylactic and therapeutic functions of drug combinations against noise-induced hearing loss.
Abstract Noise is the most common occupational and environmental hazard. Noise-induced hearing loss (NIHL) is the second most common form of sensorineural hearing deficit, after age-related hearing loss (presbycusis). Although promising approaches have been identified for reducing NIHL, currently there are no effective medications to prevent NIHL. Development of an efficacious treatment has been hampered by the complex array of cellular and molecular pathways involved in NIHL. We turned this difficulty into an advantage by asking whether NIHL could be effectively prevented by targeting multiple signaling pathways ...
Source: Hearing Research - June 18, 2013 Category: Audiology Authors: Bao J, Hungerford M, Luxmore R, Ding D, Qiu Z, Lei D, Yang A, Liang R, Ohlemiller KK Tags: Hear Res Source Type: research

Changes in utricular function during artificial endolymph injections in guinea pigs.
Abstract Various theories suggest endolymphatic hydrops may cause a rupture of the membranous labyrinth or may force open the utriculo-saccular duct, resulting in a sudden change in inner ear function. Here, we have used slow injections of artificial endolymph into either scala media or the utricle of anaesthetised guinea pigs to investigate the effects of hydrops. Vestibular function was continuously monitored in addition to the measurements of cochlear function developed in our laboratory (Brown et al. Hear Res, 2013). Scala media injection induced consistent functional changes, which occurred in two stages...
Source: Hearing Research - June 18, 2013 Category: Audiology Authors: Brown DJ, Chihara Y, Wang Y Tags: Hear Res Source Type: research

Acoustic basis of context dependent brainstem encoding of speech.
Abstract The newfound context dependent brainstem encoding of speech is evidence of online regularity detection and modulation of the sub-cortical responses. We studied the influence of spectral structure of the contextual stimulus on context dependent encoding of speech at the brainstem, in an attempt to understand the acoustic basis for this effect. Fourteen normal hearing adults participated in a randomized true experimental design in whom brainstem responses were recorded. Brainstem responses for a high pass filtered /da/ in the context of syllables, that either had same or different spectral structure were co...
Source: Hearing Research - June 18, 2013 Category: Audiology Authors: Gnanateja GN, Ranjan R, Firdose H, Sinha SK, Sandeep M Tags: Hear Res Source Type: research

A new Atp2b2 deafwaddler allele, dfw(i5), interacts strongly with Cdh23 and other auditory modifiers.
This study characterizes a novel null Atp2b2 allele, dfw(i5), by examining cochlear anatomy, vestibular function and auditory physiology in mutant mice. Loss of auditory function in PMCA2 mutants can be attributed to dysregulation of intracellular Ca(2+) inside the stereocilia bundles. However, extracellular Ca(2+) ions surrounding the stereocilia are also required for rigidity of cadherin 23, a component of the stereocilia tip-link encoded by the Cdh23 gene. This study further resolves the interaction between Atp2b2 and Cdh23 in a gene dosage and frequency-dependent manner, and finds that low frequencies are significantly...
Source: Hearing Research - June 18, 2013 Category: Audiology Authors: Watson CJ, Tempel BL Tags: Hear Res Source Type: research

Sound localization in noise and sensitivity to spectral shape.
in AT Abstract Individual differences exist in sound localization performance even for normal-hearing listeners. Some of these differences might be related to acoustical differences in localization cues carried by the head related transfer functions (HRTF). Recent data suggest that individual differences in sound localization performance could also have a perceptual origin. The localization of an auditory target in the up/down and front/back dimensions requires the analysis of the spectral shape of the stimulus. In the present study, we investigated the role of an acoustic factor, the prominence of the spectral sh...
Source: Hearing Research - June 11, 2013 Category: Audiology Authors: Andéol G, Macpherson EA, Sabin AT Tags: Hear Res Source Type: research

Development of pitch processing: Infants' discrimination of iterated rippled noise stimuli with unresolved spectral content.
Abstract Sound frequency is extracted at the level of the cochlea, and is represented by two neural codes: a spectral (place) code that is maintained by tonotopic maps extending into primary auditory cortex, and a temporal code based on the periodicity of action potentials in auditory nerve fibres. To date, little work has examined infants' ability to perceive pitch when spectral content cannot be resolved by cochlear filters; the present experiments do so using high-pass filtered iterated rippled noise (IRN) stimuli. Using a conditioned head-turn paradigm, most 8-month-old infants showed above-chance discriminati...
Source: Hearing Research - June 10, 2013 Category: Audiology Authors: Butler BE, Folland NA, Trainor LJ Tags: Hear Res Source Type: research

Uptake Mechanism of Furosemide Loaded Pegylated Nanoparticles by Cochlear Cell Lines.
This study tests the hypothesis that pegylated nanoparticles (NPs) could be taken up by the cochlear cells [House Ear Institute-organ of Corti 1 (HEI-OC1) and Stria vascularis K-1 (SVK-1)], through endocytic pathways. Furthermore, the in vitro drug release and the cytotoxicity of Furosemide (FUR)-loaded NPs on these two cochlear cells are investigated. FUR-loaded pegylated NPs are prepared by the emulsion-solvent diffusion method without surfactant. The NPs are characterized for particle mean diameter, polydispersity index (PDI), morphology, percent drug encapsulation efficiency (EE%), and FUR release kinetics. The methyl ...
Source: Hearing Research - June 6, 2013 Category: Audiology Authors: Youm I, Youan BB Tags: Hear Res Source Type: research

Cerebral origins of the auditory projection to the superior colliculus of the cat.
Abstract The superior colliculus (SC) is critical for directing accurate head and eye movements to visual and acoustic targets. In visual cortex, areas involved in orienting of the head and eyes to a visual stimulus have direct projections to the SC. In auditory cortex of the cat, four areas have been identified to be critical for the accurate orienting of the head and body to an acoustic stimulus. These areas include primary auditory cortex (A1), the posterior auditory field (PAF), the dorsal zone of auditory cortex (DZ), and the auditory field of the anterior ectosylvian sulcus (fAES). Therefore, we hypothesized...
Source: Hearing Research - May 24, 2013 Category: Audiology Authors: Chabot N, Mellott JG, Hall AJ, Tichenoff EL, Lomber SG Tags: Hear Res Source Type: research

School-age children's environmental object identification in natural auditory scenes: Effects of masking and contextual congruence.
This study investigated the development of children's skills in identifying ecologically relevant sound objects within naturalistic listening environments, using a non-linguistic analog of the classic 'cocktail-party' situation. Children aged 7-12.5 years completed a closed-set identification task in which brief, commonly encountered environmental sounds were presented at varying signal-to-noise ratios. To simulate the complexity of real-world acoustic environments, target sounds were embedded in either a single, stereophonically presented scene, or in one of two different scenes, with each scene presented to a single ear....
Source: Hearing Research - May 24, 2013 Category: Audiology Authors: Krishnan S, Leech R, Aydelott J, Dick F Tags: Hear Res Source Type: research

A null mutation of mouse Kcna10 causes significant vestibular and mild hearing dysfunction.
Abstract KCNA10 is a voltage gated potassium channel that is expressed in the inner ear. The localization and function of KCNA10 was studied in a mutant mouse, B6-Kcna10(TM45), in which the single protein coding exon of Kcna10 was replaced with a beta-galactosidase reporter cassette. Under the regulatory control of the endogenous Kcna10 promoter and enhancers, beta-galactosidase was expressed in hair cells of the vestibular organs and the organ of Corti. KCNA10 expression develops in opposite tonotopic gradients in the inner and outer hair cells. Kcna10(TM45) homozygotes display only a mild elevation in pure tone ...
Source: Hearing Research - May 24, 2013 Category: Audiology Authors: Lee SI, Conrad T, Jones SM, Lagziel A, Starost MF, Belyantseva IA, Friedman TB, Morell RJ Tags: Hear Res Source Type: research

Identification of the lateral position of a virtual object based on echoes by humans.
Abstract Echolocation offers a promising approach to improve the quality of life of people with blindness although little is known about the factors influencing object localisation using a 'searching' strategy. In this paper, we describe a series of experiments using sighted and blind human listeners and a 'virtual auditory space' technique to investigate the effects of the distance and orientation of a reflective object and the effect of stimulus bandwidth on ability to identify the right-versus-left position of the object, with bands of noise and durations from 10-400 ms. We found that performance reduced w...
Source: Hearing Research - May 24, 2013 Category: Audiology Authors: Rowan D, Papadopoulos T, Edwards D, Holmes H, Hollingdale A, Evans L, Allen R Tags: Hear Res Source Type: research

Clinical aspects of an autosomal dominantly inherited hearing impairment linked to the DFNA60 locus on chromosome 2q23.1-2q23.3.
Abstract A total of 64 loci for autosomal dominant non-syndromic hearing impairment have been described, and the causative genes have been identified for 24 of these. The present study reports on the clinical characteristics of an autosomal dominantly inherited hearing impairment that is linked to a region within the DFNA60 locus located on chromosome 2 in q22.1-24.1. A pedigree spanning four generations was established with 13 affected individuals. Linkage analysis demonstrated that the locus extended over a 2.96 Mb region flanked by markers D2S2335 and D2S2275. The audiograms mainly showed a distinctive U-s...
Source: Hearing Research - May 24, 2013 Category: Audiology Authors: van Beelen E, Schraders M, Huygen PL, Oostrik J, Plantinga RF, van Drunen W, Collin RW, Kooper DP, Pennings RJ, Cremers CW, Kremer H, Kunst HP Tags: Hear Res Source Type: research

A dynamic auditory-cognitive system supports speech-in-noise perception in older adults.
Abstract Understanding speech in noise is one of the most complex activities encountered in everyday life, relying on peripheral hearing, central auditory processing, and cognition. These abilities decline with age, and so older adults are often frustrated by a reduced ability to communicate effectively in noisy environments. Many studies have examined these factors independently; in the last decade, however, the idea of an auditory-cognitive system has emerged, recognizing the need to consider the processing of complex sounds in the context of dynamic neural circuits. Here, we used structural equation modeling to...
Source: Hearing Research - May 24, 2013 Category: Audiology Authors: Anderson S, White-Schwoch T, Parbery-Clark A, Kraus N Tags: Hear Res Source Type: research

Pitch and loudness matching of unmodulated and modulated stimuli in cochlear implantees.
Abstract The pitch elicited by unmodulated and amplitude modulated electrical pulse trains was examined with six adult cochlear implantees. In addition, for three of those subjects who had some hearing in their contralateral ear, the pitch of unmodulated electrical pulse trains was compared to that of complex harmonic acoustic tones. In the first experiment, pulse rate discrimination and the effects of place and level differences on pitch were examined for unmodulated pulse trains. General results were consistent with previous studies showing that variations in pulse rate, while holding loudness fixed, elicit chan...
Source: Hearing Research - May 16, 2013 Category: Audiology Authors: Vandali A, Sly D, Cowan R, van Hoesel R Tags: Hear Res Source Type: research

The neural processing of masked speech.
Abstract Spoken language is rarely heard in silence, and a great deal of interest in psychoacoustics has focused on the ways that the perception of speech is affected by properties of masking noise. In this review we first briefly outline the neuroanatomy of speech perception. We then summarise the neurobiological aspects of the perception of masked speech, and investigate this as a function of masker type, masker level and task. PMID: 23685149 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 16, 2013 Category: Audiology Authors: Scott SK, McGettigan C Tags: Hear Res Source Type: research

Tracing Sox10-expressing cells elucidates the dynamic development of the mouse inner ear.
Abstract The inner ear is constituted by complicated cochlear and vestibular compartments, which are derived from the otic vesicle, an embryonic structure of ectodermal origin. Although the inner ear development has been analyzed using various techniques, the developmental events have not been fully elucidated because of the intricate structure. We previously developed a Sox10-IRES-Venus mouse designed to express green fluorescent protein under the control of the Sox10 promoter. In the present study, we showed that the Sox10-IRES-Venus mouse enabled the non-destructive visualization and understanding of the morpho...
Source: Hearing Research - May 15, 2013 Category: Audiology Authors: Wakaoka T, Motohashi T, Hayashi H, Kuze B, Aoki M, Mizuta K, Kunisada T, Ito Y Tags: Hear Res Source Type: research

The incentive salience of courtship vocalizations: Hormone-mediated 'wanting' in the auditory system.
This article is part of a Special Issue entitled "Vocalizations and Hearing". PMID: 23665125 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 7, 2013 Category: Audiology Authors: Maney DL Tags: Hear Res Source Type: research

Technological, biological, and acoustical constraints to music perception in cochlear implant users.
This article is part of a Special Issue entitled "Music: A window into the hearing brain". PMID: 23665130 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 7, 2013 Category: Audiology Authors: Limb CJ, Roy AT Tags: Hear Res Source Type: research

Effect of monopolar and bipolar electric stimulation on survival and size of human spiral ganglion cells as studied by postmortem histopathology.
This study is designed to test the hypothesis that chronic electrical stimulation tends to preserve SGCs in implanted hearing-impaired ears. A total of 26 pairs of temporal bones were studied from 26 individuals who in life suffered bilateral profound hearing impairment that was symmetric (in degree of impairment and etiology) across ears and then underwent unilateral cochlear implantation. The subjects were divided in two groups by stimulus configuration: bipolar (n = 16) or monopolar (n = 10). The temporal bones were prepared for histological review by standard methods and two measures of SGC status w...
Source: Hearing Research - May 6, 2013 Category: Audiology Authors: Seyyedi M, Eddington DK, Nadol JB Tags: Hear Res Source Type: research

RNA analysis of inner ear cells from formalin fixed paraffin embedded (FFPE) archival human temporal bone section using laser microdissection - A technical report.
CONCLUSION: We detected COCH and SLC26A5 mRNA in specific structures and cells of the inner ear from archival human temporal bone. Our innovative method using laser microdissection and semi-nested RT-PCR should advance future RNA study of human inner ear diseases. PMID: 23660400 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 6, 2013 Category: Audiology Authors: Kimura Y, Kubo S, Koda H, Shigemoto K, Sawabe M, Kitamura K Tags: Hear Res Source Type: research

Effects of hearing aid amplification on voice F0 variability in speakers with prelingual hearing loss.
Abstract To investigate the audio-vocal feedback responses of (F0) to hearing amplification in severe-to-profound prelingual hearing loss (SPHL) using power spectral analysis of F0 contour of sustained vowels. Sustained phonations of vowel/a/of seventeen participants with SPHL were acquired with and without hearing-aid amplifications. The vocal intensity was visually fed back to the participants to help controlling the vocal intensity at 65-75 dBA and 85-95 dBA. The F0 contour of the phonations was extracted and submitted to spectral analysis to measure the extent of F0 fluctuations at different frequenc...
Source: Hearing Research - May 4, 2013 Category: Audiology Authors: Lee GS, Liu C, Lee SH Tags: Hear Res Source Type: research

Improving speech perception in noise with current focusing in cochlear implant users.
In this study, we compared speech perception in noise with experimental monopolar and partial tripolar speech processing strategies. The two strategies were matched in terms of number of active electrodes, microphone, filterbanks, stimulation rate and loudness (although both strategies used a lower stimulation rate than typical clinical strategies). The results of this study showed a significant improvement in speech perception in noise with partial tripolar stimulation. All subjects benefited from the current focused speech processing strategy. There was a mean improvement in speech recognition threshold of 2.7 dB in...
Source: Hearing Research - May 1, 2013 Category: Audiology Authors: Srinivasan AG, Padilla M, Shannon RV, Landsberger DM Tags: Hear Res Source Type: research

Cisplatin-induced ototoxicity: Transporters playing a role in cisplatin toxicity.
Abstract Cisplatin is a potent antineoplastic agent widely used for a variety of cancer types. Unfortunately, its use leads to dose limiting side effects such as ototoxicity. Up to 93% of patients receiving cisplatin chemotherapy will develop progressive and irreversible sensorineural hearing loss which leads to a decreased quality of life in cancer survivors. No treatment is currently available for cisplatin-induced ototoxicity. It appears that cisplatin causes apoptosis by binding DNA, activating the inflammatory cascade as well as generating oxidative stress in the cell. Various studies have aimed to assess the...
Source: Hearing Research - May 1, 2013 Category: Audiology Authors: Waissbluth S, Daniel SJ Tags: Hear Res Source Type: research

Effects of sex and age on auditory spatial scene analysis.
Abstract Recently, it has been demonstrated that men outperform women in spatial analysis of complex auditory scenes (Zündorf et al., 2011). The present study investigated the relation between the effects of ageing and sex on the spatial segregation of concurrent sounds in younger and middle-aged adults. The experimental design allowed simultaneous presentation of target and distractor sound sources at different locations. The resulting spatial "pulling" effect (that is, the bias of target localization toward that of the distractor) was used as a measure of performance. The pulling effect was s...
Source: Hearing Research - May 1, 2013 Category: Audiology Authors: Lewald J, Hausmann M Tags: Hear Res Source Type: research

Characterization of a novel ENU-generated myosin VI mutant mouse strain with congenital deafness and vestibular dysfunction.
Abstract Myosin VI (Myo6) is known to play an important role in the mammalian auditory and vestibular systems. We have identified a novel N-ethyl-N-nitrosourea mutagenised mouse strain, charlie, carrying an intronic Myo6 splice site mutation. This mutation (IVS5+5G > A) results in skipping of exon 5, and is predicted to cause a frameshift and premature termination of the protein. We detected essentially no Myo6 transcript in tissue from charlie homozygous mutant mice (Myo6(chl/chl)). Myo6(chl/chl) mice exhibit vestibular dysfunction and profound hearing impairment when first tested at four weeks of ag...
Source: Hearing Research - May 1, 2013 Category: Audiology Authors: Williams LH, Miller KA, Dahl HH, Manji SS Tags: Hear Res Source Type: research

Auditory evoked magnetic fields in individuals with tinnitus.
Abstract Some forms of tinnitus are likely to be perceptual consequences of altered neural activity in the central auditory system triggered by damage to the auditory periphery. Animal studies report changes in the evoked responses after noise exposure or ototoxic drugs in inferior colliculus and auditory cortex. However, human electrophysiological evidence is rather equivocal: increased, reduced or no difference in N1/N1m evoked amplitudes and latencies in tinnitus participants have been reported. The present study used magnetoencephalography to seek evidence for altered evoked responses in people with tinnitus c...
Source: Hearing Research - April 29, 2013 Category: Audiology Authors: Sereda M, Adjamian P, Edmondson-Jones M, Palmer AR, Hall DA Tags: Hear Res Source Type: research

Electrically evoked compound action potential artifact rejection by independent component analysis: Technique validation.
Abstract The electrically-evoked compound action potential (ECAP) is the synchronous whole auditory nerve activity in response to an electrical stimulus, and can be recorded in situ on cochlear implant (CI) electrodes. A novel procedure (ECAP-ICA) to isolate the ECAP from the stimulation artifact, based on independent component analysis (ICA), is described here. ECAPs with artifact (raw-ECAPs) were sequentially recorded for the same stimulus on 9 different intracochlear recording electrodes. The raw-ECAPs were fed to ICA, which separated them into independent sources. Restricting the ICA projection to 4 independen...
Source: Hearing Research - April 28, 2013 Category: Audiology Authors: Akhoun I, McKay CM, El-Deredy W Tags: Hear Res Source Type: research

Amplitude-modulation detection by gerbils in reverberant sound fields.
Abstract Reverberation can dramatically reduce the depth of amplitude modulations which are critical for speech intelligibility. Psychophysical experiments indicate that humans' sensitivity to amplitude modulation in reverberation is better than predicted from the acoustic modulation depth at the receiver position. Electrophysiological studies on reverberation in rabbits highlight the contribution of neurons sensitive to interaural correlation. Here, we use a prepulse-inhibition paradigm to quantify the gerbils' amplitude modulation threshold in both anechoic and reverberant virtual environments. Data show that pr...
Source: Hearing Research - April 18, 2013 Category: Audiology Authors: Lingner A, Kugler K, Grothe B, Wiegrebe L Tags: Hear Res Source Type: research