Brainstem response to speech and non-speech stimuli in children with learning problems.
Abstract Neuronal firing synchronization is critical for recording auditory responses from the brainstem. Recent studies have shown that both click and/da/synthetic syllable (speech) stimuli perform well in evoking neuronal synchronization at the brainstem level. In the present study, brainstem responses to click and speech stimuli were compared between children with learning problems (LP) and those with normal learning (NL) abilities. The study included 49 children with LP and 34 children with NL. Auditory brainstem response (ABR) to 100-μs click stimulus and speech ABR (sABR) to/da/40-ms stimulus were tested ...
Source: Hearing Research - May 10, 2014 Category: Audiology Authors: Malayeri S, Lotfi Y, Moossavi SA, Rostami R, Faghihzadeh S Tags: Hear Res Source Type: research

Individual differences in attentional modulation of cortical responses correlate with selective attention performance.
Abstract Many studies have shown that attention modulates the cortical representation of an auditory scene, emphasizing an attended source while suppressing competing sources. Yet, individual differences in the strength of this attentional modulation and their relationship with selective attention ability are poorly understood. Here, we ask whether differences in how strongly attention modulates cortical responses reflect differences in normal-hearing listeners' selective auditory attention ability. We asked listeners to attend to one of three competing melodies and identify its pitch contour while we measured cor...
Source: Hearing Research - May 9, 2014 Category: Audiology Authors: Choi I, Wang L, Bharadwaj H, Shinn-Cunningham B Tags: Hear Res Source Type: research

The connexin 30.3 of zebrafish homologue of human connexin 26 may play similar role in the inner ear.
In this study, using bioinformatics, we found that two zebrafish cx genes, cx27.5 and cx30.3, are likely homologous to human and mouse GJB2. During embryogenesis, zebrafish cx27.5 was rarely expressed at 1.5-3 hours post-fertilization (hpf), but a relatively high level of cx27.5 expression was detected from 6-96 hpf. However, zebrafish cx30.3 transcripts were hardly detected until 9 hpf. The temporal experiment was conducted in whole larvae. Both cx27.5 and cx30.3 transcripts were revealed significantly in the inner ear by reverse transcription polymerase chain reaction (RT-PCR) and whole-mount in situ hybridization (WISH)...
Source: Hearing Research - May 5, 2014 Category: Audiology Authors: Chang-Chien J, Yen YC, Chien KH, Li SY, Hsu TC, Yang JJ Tags: Hear Res Source Type: research

Behavioral responses of deafened guinea pigs to intracochlear electrical stimulation: A new rapid psychophysical procedure.
In conclusion, the present study demonstrates that guinea pigs can be trained relatively fast to respond to acoustic stimuli, and that the training has a lasting effect, which generalizes to intracochlear electrical stimulation after deafening. Furthermore, it demonstrates that bilaterally deafened guinea pigs with substantial (∼50%) loss of spiral ganglion cells (SGCs), detect intracochlear electrical stimulation. PMID: 24811981 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 5, 2014 Category: Audiology Authors: Agterberg MJ, Versnel H Tags: Hear Res Source Type: research

Acetaminophen and NAPQI are toxic to auditory cells via oxidative and endoplasmic reticulum stress-dependent pathways.
In this study, we report cellular, genomic, and proteomic experiments revealing that cytotoxicity by APAP and NAPQI involves two different pathways in Immortomouse™-derived HEI-OC1 cells, implicating ROS overproduction, alterations in ER morphology, redistribution of intra-cisternal chaperones, activation of the eIF2α-CHOP pathway, as well as changes in ER stress and protein folding response markers. Thus, both oxidative and ER stress are part of the cellular and molecular mechanisms that contribute to the cytotoxic effects of APAP and NAPQI in these cells. We suggest that these in vitro findings should be...
Source: Hearing Research - April 30, 2014 Category: Audiology Authors: Kalinec GM, Thein P, Parsa A, Yorgason J, Luxford W, Urrutia R, Kalinec F Tags: Hear Res Source Type: research

Effects of the intensity of masking noise on ear canal recorded low-frequency cochlear microphonic waveforms in normal hearing subjects.
In conclusion, when masked with high-pass noise, the low-frequency CMs are measurable at the human ear canal. Such noise reduces the low-frequency CM amplitude. The reduction is noise-intensity dependent but not completely linear. The reduction may be caused by the excited basal cochlea which the low-frequency has to travel and pass through. Although not completely clear, six mechanisms related to such reduction are discussed. PMID: 24793117 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 30, 2014 Category: Audiology Authors: Zhang M Tags: Hear Res Source Type: research

Thin and open vessel windows for intra-vital fluorescence imaging of murine cochlear blood flow.
Abstract Normal microvessel structure and function in the cochlea is essential for maintaining the ionic and metabolic homeostasis required for hearing function. Abnormal cochlear microcirculation has long been considered an etiologic factor in hearing disorders. A better understanding of cochlear blood flow (CoBF) will enable more effective amelioration of hearing disorders that result from aberrant blood flow. However, establishing the direct relationship between CoBF and other cellular events in the lateral wall and response to physio-pathological stress remains a challenge due to the lack of feasible interroga...
Source: Hearing Research - April 26, 2014 Category: Audiology Authors: Shi X, Zhang F, Urdang Z, Dai M, Neng L, Zhang J, Chen S, Ramamoorthy S, Nuttall AL Tags: Hear Res Source Type: research

Comparison of auditory responses determined by acoustic stimulation and by mechanical round window stimulation at equivalent stapes velocities.
In conclusion, this study showed that the amplitudes and latencies of the ABRs of acoustic and RW stimulation showed significant differences at comparable stapes velocities in an in vivo system. These differences in the ABR amplitudes and latencies reflect different output functions of the cochlea in response to different stimulation pathways. Therefore, it is necessary to develop a new method for quantifying the output of the cochlea in the case of RW stimulation. PMID: 24768763 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 24, 2014 Category: Audiology Authors: Lee J, Seong K, Lee SH, Lee KY, Cho JH Tags: Hear Res Source Type: research

Time-frequency analysis of transient evoked-otoacoustic emissions in individuals with auditory neuropathy spectrum disorder.
Abstract The aim of the study was to describe and quantify the cochlear active mechanisms in individuals with Auditory Neuropathy Spectrum Disorders (ANSD). Transient Evoked Otoacoustic Emissions (TEOAEs) were recorded in 15 individuals with ANSD and 22 individuals with normal hearing. TEOAEs were analyzed by Wavelet transform method to describe and quantify the characteristics of TEOAEs in narrow-band frequency regions. It was noted that the amplitude of TEOAEs was higher and latency slightly shorter in individuals with ANSD compared to normal hearing individuals at low and mid frequencies. The increased amplitud...
Source: Hearing Research - April 24, 2014 Category: Audiology Authors: Narne VK, Prabhu PP, Chatni S Tags: Hear Res Source Type: research

Loudness perception affected by early age hearing loss.
In this study, sound loudness changes in rats affected by perforation of the tympanic membranes (TM) have been studied using an operant conditioning based behavioral task. We detected significant increases of sound loudness and susceptibility to audiogenic seizures (AGS) in rats with bilateral TM damage at postnatal 16 days. As increase to sound sensitivity is commonly seen in hyperacusis and tinnitus patients, these results suggest that early age hearing loss is a high risk factor to induce tinnitus and hyperacusis in children. In the TM damaged rats, we also detected a reduced expression of GABA receptor δ and &alp...
Source: Hearing Research - April 18, 2014 Category: Audiology Authors: Sun W, Fu Q, Zhang C, Manohar S, Kumaraguru A, Li J Tags: Hear Res Source Type: research

Modeling the utility of binaural cues for underwater sound localization.
Abstract The binaural cues used by terrestrial animals for sound localization in azimuth may not always suffice for accurate sound localization underwater. The purpose of this research was to examine the theoretical limits of interaural timing and level differences available underwater using computational and physical models. A paired-hydrophone system was used to record sounds transmitted underwater and recordings were analyzed using neural networks calibrated to reflect the auditory capabilities of terrestrial mammals. Estimates of source direction based on temporal differences were most accurate for frequencies...
Source: Hearing Research - April 12, 2014 Category: Audiology Authors: Schneider JN, Lloyd DR, Banks PN, Mercado E Tags: Hear Res Source Type: research

Selective attention reduces physiological noise in the external ear canals of humans. I: Auditory attention.
In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring, or not requiring, selective auditory attention. Appended to each stimulus presentation, and included in the calculation of each nSFOAE response, was a 30-ms silent period that was used to estimate the level of the inherent physiological noise in the ear canals of our subjects during each behavioral condition. Physiological-noise magnitudes were higher (noisier) for all subjects in the inattention task, and lowe...
Source: Hearing Research - April 11, 2014 Category: Audiology Authors: Walsh KP, Pasanen EG, McFadden D Tags: Hear Res Source Type: research

Selective attention reduces physiological noise in the external ear canals of humans. II: Visual attention.
Abstract Human subjects performed in several behavioral conditions requiring, or not requiring, selective attention to visual stimuli. Specifically, the attentional task was to recognize strings of digits that had been presented visually. A nonlinear version of the stimulus-frequency otoacoustic emission (SFOAE), called the nSFOAE, was collected during the visual presentation of the digits. The segment of the physiological response discussed here occurred during brief silent periods immediately following the SFOAE-evoking stimuli. For all subjects tested, the physiological-noise magnitudes were substantially weake...
Source: Hearing Research - April 11, 2014 Category: Audiology Authors: Walsh KP, Pasanen EG, McFadden D Tags: Hear Res Source Type: research

Round Window Stimulation with the Floating Mass Transducer at Constant Pretension.
Abstract OBJECTIVE: Mechanical stimulation of the round window (RW) of the cochlea is successfully done with the Vibrant Soundbridge (Med-El), but clinical outcomes show a substantial degree of variability. One source of variability is variation in the pre-load static force applied by the stimulator to the round window (Maier et al., 2013), in this study we investigate other sources of variability by maintaining a constant static-force pre-load while investigating the effect of a coupler device and the interposition of soft tissue between the stimulator and the RW. STUDY DESIGN: Experimental METHODS: The stap...
Source: Hearing Research - April 10, 2014 Category: Audiology Authors: Salcher R, Schwab B, Lenarz T, Maier H Tags: Hear Res Source Type: research

Natural variability in species-specific vocalizations constrains behavior and neural activity.
Abstract A listener's capacity to discriminate between sounds is related to the amount of acoustic variability that exists between these sounds. However, a full understanding of how this natural variability impacts neural activity and behavior is lacking. Here, we tested monkeys' ability to discriminate between different utterances of vocalizations from the same acoustic class (i.e., coos and grunts), while neural activity was simultaneously recorded in the anterolateral belt region (AL) of the auditory cortex, a brain region that is a part of a pathway that mediates auditory perception. Monkeys could discriminate...
Source: Hearing Research - April 7, 2014 Category: Audiology Authors: Christison-Lagay KL, Bennur S, Blackwell J, Lee JH, Schroeder T, Cohen YE Tags: Hear Res Source Type: research

Photons and Neurons.
Abstract Methods to control neural activity by light have been introduced to the field of neuroscience. During the last decade, several techniques have been established, including optogenetics, thermogenetics, and infrared neural stimulation. The techniques allow investigators to turn-on or turn-off neural activity. This review is an attempt to show the importance of the techniques for the auditory field and provide insight in the similarities, overlap, and differences of the techniques. Discussing the mechanism of each of the techniques will shed light on the abilities and challenges for each of the techniques. T...
Source: Hearing Research - April 4, 2014 Category: Audiology Authors: Richter CP, Tan X Tags: Hear Res Source Type: research

Independent or integrated processing of interaural time and level differences in human auditory cortex?
We presented a series of diotic standards (perceived at a midline position) that were interrupted by deviants that entailed either a change in a) ITD only, b) ILD only, c) congruent ITD and ILD, or d) counterbalanced ITD/ILD (ITD/ILD trading). The sound stimuli were either i) pure tones with a frequency of 500 Hz, or ii) amplitude modulated tones with a carrier frequency of 4000 Hz and a modulation frequency of 125 Hz. We observed significant MMN for the ITD/ILD traded deviants in case of the 500 Hz pure tones, and for the 4000 Hz amplitude-modulated tone. This speaks for independent processing of ITD and ILD at the level ...
Source: Hearing Research - April 4, 2014 Category: Audiology Authors: Altmann CF, Terada S, Kashino M, Goto K, Mima T, Fukuyama H, Furukawa S Tags: Hear Res Source Type: research

The pupil response is sensitive to divided attention during speech processing.
Abstract Dividing attention over two streams of speech strongly decreases performance compared to focusing on only one. How divided attention affects cognitive processing load as indexed with pupillometry during speech recognition has so far not been investigated. In 12 young adults the pupil response was recorded while they focused on either one or both of two sentences that were presented dichotically and masked by fluctuating noise across a range of signal-to-noise ratios. In line with previous studies, the performance decreases when processing two target sentences instead of one. Additionally, dividing attenti...
Source: Hearing Research - April 4, 2014 Category: Audiology Authors: Koelewijn T, Shinn-Cunningham BG, Zekveld AA, Kramer SE Tags: Hear Res Source Type: research

Source analysis of short and long latency vestibular-evoked potentials (VsEPs) produced by left vs. right ear air-conducted 500 Hz pips.
Source analysis of short and long latency vestibular-evoked potentials (VsEPs) produced by left vs. right ear air-conducted 500 Hz pips. Hear Res. 2014 Apr 1; Authors: Todd NP, Paillard AC, Kluk K, Whittle E, Colebatch JG Abstract Todd et al. (2014) have recently demonstrated the presence of vestibular dependent changes both in the morphology and in the intensity dependence of auditory evoked potentials (AEPs) when passing through the vestibular threshold as determined by vestibular evoked myogenic potentials (VEMPs). In this paper we extend this work by comparing left vs. right ear stimulat...
Source: Hearing Research - April 1, 2014 Category: Audiology Authors: Todd NP, Paillard AC, Kluk K, Whittle E, Colebatch JG Tags: Hear Res Source Type: research

Viscoelastic properties of the human tympanic membrane studied with stroboscopic holography and finite element modeling.
Abstract A new anatomically-accurate Finite Element (FE) model of the tympanic membrane (TM) and malleus was combined with measurements of the sound-induced motion of the TM surface and the bony manubrium, in an isolated TM-malleus preparation. Using the results, we were able to address two issues related to how sound is coupled to the ossicular chain: (i) Estimate the viscous damping within the tympanic membrane itself, the presence of which may help smooth the broadband response of a potentially highly resonant TM, and (ii) Investigate the function of a peculiar feature of human middle-ear anatomy, the thin muco...
Source: Hearing Research - March 19, 2014 Category: Audiology Authors: De Greef D, Aernouts J, Aerts J, Cheng JT, Horwitz R, Rosowski JJ, Dirckx JJ Tags: Hear Res Source Type: research

The dissimilar time course of temporary threshold shifts and reduction of inhibition in the inferior colliculus following intense sound exposure.
Abstract Excessive noise exposure is known to produce an auditory threshold shift, which can be permanent or transient in nature. Recent studies showed that noise-induced temporary threshold shifts are associated with loss of synaptic connections to the inner hair cells and with cochlear nerve degeneration, which is reflected in a decreased amplitude of wave I of the auditory brainstem response (ABR). This suggests that, despite normal auditory thresholds, central auditory processing may be abnormal. We recorded changes in central auditory processing following a sound-induced temporary threshold shift. Anesthetize...
Source: Hearing Research - March 18, 2014 Category: Audiology Authors: Heeringa AN, van Dijk P Tags: Hear Res Source Type: research

Mechanisms of radiation-induced sensorineural hearing loss and radioprotection.
Abstract Patients that receive radiotherapy are at risk of late sensorineural hearing loss when the inner ear is included within the radiation field. Preclinical and human temporal bone studies have shown that there is differential damage to cochlear structures depending on the amount of dose delivered to the inner ear. In vitro studies have suggested that reactive oxygen species (ROS) are the main initial actors in radiation-induced damage. The interaction of ROS with different cellular components can result in different apoptotic pathways. Therefore, approaches to radioprotection are mainly aimed to reduce ...
Source: Hearing Research - March 18, 2014 Category: Audiology Authors: Mujica-Mota MA, Lehnert S, Devic S, Gasbarrino K, Daniel SJ Tags: Hear Res Source Type: research

Cochlear implantation in the mouse via the round window: Effects of array insertion.
Cochlear implantation in the mouse via the round window: Effects of array insertion. Hear Res. 2014 Mar 18; Authors: Mistry N, Nolan LS, Saeed SR, Forge A, Taylor RR Abstract Animal models are the only means of assessing the effects of cochlear implantation (CI) at a cellular and molecular level. The range of naturally occurring and genetically-modified mouse strains which mimic human deafness provide excellent opportunities for auditory research. To date, there are very few studies of CI in mice. The main aims of this study were to develop a reproducible and viable technique to enable long term CI in...
Source: Hearing Research - March 18, 2014 Category: Audiology Authors: Mistry N, Nolan LS, Saeed SR, Forge A, Taylor RR Tags: Hear Res Source Type: research

Tinnitus-related dissociation between cortical and subcortical neural activity in humans with mild to moderate sensorineural hearing loss.
In this study, cortical and sub-cortical sound-evoked brain responses in 34 hearing-impaired chronic tinnitus patients and 19 hearing level-matched controls were studied using 3-T functional magnetic resonance imaging (fMRI). Auditory stimuli were presented to either the left or the right ear at levels of 30-90 dB SPL. We extracted neural activation as a function of sound intensity in eight auditory regions (left and right auditory cortices, medial geniculate bodies, inferior colliculi and cochlear nuclei), the cerebellum and a cinguloparietal task-positive region. The activation correlated positively with the stimulus int...
Source: Hearing Research - March 11, 2014 Category: Audiology Authors: Boyen K, de Kleine E, van Dijk P, Langers DR Tags: Hear Res Source Type: research

Localization and interaural time difference (ITD) thresholds for cochlear implant recipients with preserved acoustic hearing in the implanted ear.
Abstract The purpose of this study was to investigate horizontal plane localization and interaural time difference (ITD) thresholds for 14 adult cochlear implant recipients with hearing preservation in the implanted ear. Localization to broadband noise was assessed in an anechoic chamber with a 33-loudspeaker array extending from -90 to +90 degrees. Three listening conditions were tested including bilateral hearing aids, bimodal (implant + contralateral hearing aid) and best aided (implant + bilateral hearing aids). ITD thresholds were assessed, under headphones, for low-frequency stimuli including a 250-Hz tone a...
Source: Hearing Research - March 6, 2014 Category: Audiology Authors: Gifford RH, Grantham DW, Sheffield SW, Davis TJ, Dwyer R, Dorman MF Tags: Hear Res Source Type: research

Manganese enhanced magnetic resonance imaging (MEMRI): A powerful new imaging method to study tinnitus.
This article is part of a Special Issue entitled . PMID: 24583078 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - February 26, 2014 Category: Audiology Authors: Cacace AT, Brozoski T, Berkowitz B, Bauer C, Odintsov B, Bergkvist M, Castracane J, Zhang J, Holt AG Tags: Hear Res Source Type: research

Contribution of Bimodal Hearing to Lexical Tone Normalization in Mandarin-speaking Cochlear Implant Users.
In this study, native Mandarin NH listeners and pre-lingually deafened unilaterally implanted CI users were asked to recognize a series of Mandarin tones varying from Tone 1 (high-flat) to Tone 2 (mid-rising) with or without a preceding sentence context. Most of the CI subjects used a hearing aid (HA) in the non-implanted ear (i.e., bimodal users) and were tested both with CI alone and CI+HA. In the test without context, typical S-shaped tone recognition functions were observed for most CI subjects and the function slopes and perceptual boundaries were similar with either CI alone or CI+HA. Compared to NH subjects, CI subj...
Source: Hearing Research - February 24, 2014 Category: Audiology Authors: Luo X, Chang YP, Lin CY, Chang RY Tags: Hear Res Source Type: research

Central auditory function of deafness genes.
Abstract The highly variable benefit of hearing devices is a serious challenge in auditory rehabilitation. Various factors contribute to this phenomenon such as the diversity in ear defects, the different extent of auditory nerve hypoplasia, the age of intervention, and cognitive abilities. Recent analyses indicate that, in addition, central auditory functions of deafness genes have to be considered in this context. Since reduced neuronal activity acts as the common denominator in deafness, it is widely assumed that peripheral deafness influences development and function of the central auditory system in a stereot...
Source: Hearing Research - February 21, 2014 Category: Audiology Authors: Willaredt MA, Ebbers L, Nothwang HG Tags: Hear Res Source Type: research

Insertion Site and Sealing Technique Affect Residual Hearing and Tissue Formation after Cochlear Implantation.
Abstract Tissue formation around the electrode array of a cochlear implant has been suggested to influence preservation of residual hearing as well as electrical hearing performance of implanted subjects. Further, inhomogeneity in the electrical properties of the scala tympani shape the electrical field and affect current spread. Intracochlear trauma due to electrode insertion and the insertion site itself are commonly seen as triggers for the tissue formation. The present study investigates whether the insertion site, round window membrane (RWM) vs. cochleostomy (CS), or the sealing material, no seal vs. muscle g...
Source: Hearing Research - February 21, 2014 Category: Audiology Authors: Burghard A, Lenarz T, Kral A, Paasche G Tags: Hear Res Source Type: research

Ocular vestibular evoked myogenic potential frequency tuning in certain Menière's disease.
Ocular vestibular evoked myogenic potential frequency tuning in certain Menière's disease. Hear Res. 2014 Feb 13; Authors: Jerin C, Berman A, Krause E, Ertl-Wagner B, Gürkov R Abstract Ocular vestibular evoked myogenic potentials (oVEMP) represent extraocular muscle activity in response to vestibular stimulation. To specify the value of oVEMP in the diagnostics of Menière's disease, the amplitude ratio between 500 and 1000 Hz stimuli was investigated. Thirty-nine patients with certain Menière's disease, i.e. definite Menière's disease with visualization of endolymphatic hyd...
Source: Hearing Research - February 13, 2014 Category: Audiology Authors: Jerin C, Berman A, Krause E, Ertl-Wagner B, Gürkov R Tags: Hear Res Source Type: research

Residual inhibition of tinnitus induced by 30-kHz bone-conducted ultrasound.
This study investigated whether RI could be induced by BCU. Five types of the masker sounds were used to measure RI in 21 subjects with tinnitus. A bone-conducted 30-kHz pure tone was used as a BCU, and an air-conducted 4-kHz pure tone, narrow-band noise, white noise, and a bone-conducted 4-kHz pure tone were used as controls of audible sounds. The masker intensities of the 30-kHz BCU and audible sounds were set at the minimum masking levels of tinnitus plus 3 and 10 dB, respectively, considering the narrow dynamic range of BCU. The duration of RI induced by the 30-kHz BCU was significantly longer than those induced b...
Source: Hearing Research - February 12, 2014 Category: Audiology Authors: Koizumi T, Nishimura T, Yamashita A, Yamanaka T, Imamura T, Hosoi H Tags: Hear Res Source Type: research

Spatial and temporal modifications of multitalker speech can improve speech perception in older adults.
This study investigated two signal-processing techniques that have been suggested as a means of improving speech perception accuracy of older adults: time stretching and spatial separation of target talkers. Stimuli in each experiment comprised 2-4 fixed-form utterances in which listeners were asked to consecutively 1) detect concurrently spoken keywords in the beginning of the utterance (divided attention); and, 2) identify additional keywords from only one talker at the end of the utterance (selective attention). In Experiment 1, the overall tempo of each utterance was unaltered or slowed down by 25%; in Experiment 2 the...
Source: Hearing Research - February 12, 2014 Category: Audiology Authors: Gygi B, Shafiro V Tags: Hear Res Source Type: research

A summary of research investigating echolocation abilities of blind and sighted humans.
Abstract There is currently considerable interest in the consequences of loss in one sensory modality on the remaining senses. Much of this work has focused on the development of enhanced auditory abilities among blind individuals, who are often able to use sound to navigate through space. It has now been established that many blind individuals produce sound emissions and use the returning echoes to provide them with information about objects in their surroundings, in a similar manner to bats navigating in the dark. In this review, we summarize current knowledge regarding human echolocation. Some blind individuals...
Source: Hearing Research - February 10, 2014 Category: Audiology Authors: Kolarik AJ, Cirstea S, Pardhan S, Moore BC Tags: Hear Res Source Type: research

Auditory responses to electric and infrared neural stimulation of the rat cochlear nucleus.
Abstract In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, clo...
Source: Hearing Research - February 5, 2014 Category: Audiology Authors: Verma R, Guex AA, Hancock KE, Durakovic N, McKay CM, Slama MC, Brown MC, Lee DJ Tags: Hear Res Source Type: research

Morphological and physiological development of auditory synapses.
Abstract Acoustic communication requires gathering, transforming, and interpreting diverse sound cues. To achieve this, all the spatial and temporal features of complex sound stimuli must be captured in the firing patterns of the primary sensory neurons and then accurately transmitted along auditory pathways for additional processing. The mammalian auditory system relies on several synapses with unique properties in order to meet this task: the auditory ribbon synapses, the endbulb of Held, and the calyx of Held. Each of these synapses develops morphological and electrophysiological characteristics that enable the...
Source: Hearing Research - February 5, 2014 Category: Audiology Authors: Yu WM, Goodrich LV Tags: Hear Res Source Type: research

Evaluation of the sparse coding shrinkage noise reduction algorithm in normal hearing and hearing impaired listeners.
Abstract Although there are numerous single-channel noise reduction strategies to improve speech perception in noise, most of them improve speech quality but do not improve speech intelligibility, in circumstances where the noise and speech have similar frequency spectra. Current exceptions that may improve speech intelligibility are those that require a priori knowledge of the speech or noise statistics, which limits practical application. Hearing impaired (HI) listeners suffer more in speech intelligibility than normal hearing listeners (NH) in the same noisy environment, so developing better single-channel nois...
Source: Hearing Research - February 1, 2014 Category: Audiology Authors: Sang J, Hu H, Zheng C, Li G, Lutman ME, Bleeck S Tags: Hear Res Source Type: research

In vitro assessment of antiretroviral drugs demonstrates potential for ototoxicity.
In vitro assessment of antiretroviral drugs demonstrates potential for ototoxicity. Hear Res. 2014 Jan 31; Authors: Thein P, Kalinec GM, Park C, Kalinec F Abstract Several studies have reported an increased incidence of auditory dysfunction among HIV/AIDS patients. We used auditory HEI-OC1 cells in cell viability, flow cytometry and caspases 3/7-activation studies to investigate the potential ototoxicity of fourteen HIV antiretroviral agents: Abacavir, AZT, Delavirdine, Didenosine, Efavirenz, Emtricitabine, Indinavir, Lamivudine, Nefinavir, Nevirapine, Tenofovir, Ritonavir, Stavudine and Zalcitabine, ...
Source: Hearing Research - January 31, 2014 Category: Audiology Authors: Thein P, Kalinec GM, Park C, Kalinec F Tags: Hear Res Source Type: research

Effect of different stapes prostheses on the passive vibration of the basilar membrane.
Abstract The effect of different stapes prostheses on the basilar membrane (BM) motion was determined. To that end, a three dimensional finite-element (FE) model of the passive human cochlea was developed. Passive responses of the BM were found based on coupled fluid-structure interactions between the cochlear solid structures and the scala fluids. The passive BM vibrations in normal (healthy) cochlea were compared with vibrations in the cochlea in which a 0.4-mm piston or a proposed new type of prosthesis was implanted. The proposed chamber prosthesis was not experimentally implanted, but only numerically simulat...
Source: Hearing Research - January 22, 2014 Category: Audiology Authors: Kwacz M, Marek P, Borkowski P, Gambin W Tags: Hear Res Source Type: research

A subset of chicken statoacoustic ganglion neurites are repelled by Slit1 and Slit2.
A subset of chicken statoacoustic ganglion neurites are repelled by Slit1 and Slit2. Hear Res. 2014 Jan 21; Authors: Battisti AC, Fantetti KN, Moyers BA, Fekete DM Abstract Mechanosensory hair cells in the chicken inner ear are innervated by bipolar afferent neurons of the statoacoustic ganglion (SAG). During development, individual SAG neurons project their peripheral process to only one of eight distinct sensory organs. These neuronal subtypes may respond differently to guidance cues as they explore the periphery in search of their target. Previous gene expression data suggested that Slit repellants...
Source: Hearing Research - January 21, 2014 Category: Audiology Authors: Battisti AC, Fantetti KN, Moyers BA, Fekete DM Tags: Hear Res Source Type: research

The layering of auditory experiences in driving experience-dependent subcortical plasticity.
Abstract Auditory brain function is shaped by a combination of genetic factors and one's auditory experiences. Genetic factors set the gross architecture of the system, whereas experiences fine-tune that architecture and its functionality throughout life. In this review article, we focus on recent discoveries of experiential influences on brainstem function. Using these studies as scaffolding, we then lay the initial groundwork for the Layering Hypothesis, a new hypothesis of experience-dependent plasticity that explicates how experiences combine to shape subcortical auditory function. Our hypothesis is built on t...
Source: Hearing Research - January 17, 2014 Category: Audiology Authors: Skoe E, Chandrasekaran B Tags: Hear Res Source Type: research

TMC function in hair cell transduction.
This article is part of a Special Issue entitled . PMID: 24423408 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - January 11, 2014 Category: Audiology Authors: Holt JR, Pan B, Koussa MA, Asai Y Tags: Hear Res Source Type: research

Factors affecting loss of tympanic membrane mobility in acute otitis media model of chinchilla.
In this study, a chinchilla AOM model was produced by transbullar injection of Haemophilus influenzae. Mobility of the TM at the umbo was measured by laser vibrometry in two treatment groups: 4 days (4D) and 8 days (8D) post inoculation. These time points represent relatively early and later phases of AOM. In each group, the vibration of the umbo was measured at three experimental stages: unopened, pressure-released, and effusion-removed ears. The effects of MEP and MEE and middle ear structural changes were quantified in each group by comparing the TM mobility at one stage with that of the previous stage. Our findings sho...
Source: Hearing Research - January 7, 2014 Category: Audiology Authors: Guan X, Chen Y, Gan RZ Tags: Hear Res Source Type: research

Tinnitus in men, mice (as well as other rodents), and machines.
This article is part of a Special Issue entitled . PMID: 24374091 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - December 25, 2013 Category: Audiology Authors: Schaette R Tags: Hear Res Source Type: research

Top-Down Restoration of Speech in Cochlear-Implant Users.
Abstract In noisy listening conditions, intelligibility of degraded speech can be enhanced by top-down restoration. Cochlear implant (CI) users have difficulty understanding speech in noisy environments. This could partially be due to reduced top-down restoration of speech, caused by the changes that the electrical stimulation imposes on the bottom-up cues. We tested this hypothesis using the phonemic restoration (PhR) paradigm in which speech interrupted with periodic silent intervals is perceived illusorily continuous (continuity illusion or CoI) and becomes more intelligible (PhR benefit) when the interruptions...
Source: Hearing Research - December 21, 2013 Category: Audiology Authors: Bhargava P, Gaudrain E, Başkent D Tags: Hear Res Source Type: research

Prestin at Year 14: Progress and Prospect.
This article reviews recent advances of the structural and functional properties of prestin with focus on the areas that are critical but still controversial in understanding the molecular mechanism of how prestin works: The structural domains for voltage sensing and interaction with anions and for conformational change. Future research directions and potential application of prestin are also discussed. PMID: 24361298 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - December 17, 2013 Category: Audiology Authors: He DZ, Lovas S, Ai Y, Li Y, Beisel KW Tags: Hear Res Source Type: research

Sustained attention, selective attention and cognitive control in deaf and hearing children.
Abstract Deaf children have been characterized as being impulsive, distractible, and unable to sustain attention. However, past research has tested deaf children born to hearing parents who are likely to have experienced language delays. The purpose of this study was to determine whether an absence of auditory input modulates attentional problems in deaf children with no delayed exposure to language. Two versions of a continuous performance test were administered to 37 deaf children born to Deaf parents and 60 hearing children, all aged 6-13 years. A vigilance task was used to measure sustained attention over the ...
Source: Hearing Research - December 16, 2013 Category: Audiology Authors: Dye MW, Hauser PC Tags: Hear Res Source Type: research

Auditory cortex activation to natural speech and simulated cochlear implant speech measured with functional near-infrared spectroscopy.
In this study, we sought to determine whether functional near-infrared spectroscopy (fNIRS), a non-invasive neuroimaging method which is safe to use repeatedly and for extended periods of time, can provide an objective measure of whether a subject is hearing normal speech or distorted speech. We used a 140 channel fNIRS system to measure activation within the auditory cortex in 19 normal hearing subjects while they listed to speech with different levels of intelligibility. Custom software was developed to analyze the data and compute topographic maps from the measured changes in oxyhemoglobin and deoxyhemoglobin concentrat...
Source: Hearing Research - December 13, 2013 Category: Audiology Authors: Pollonini L, Olds C, Abaya H, Bortfeld H, Beauchamp MS, Oghalai JS Tags: Hear Res Source Type: research

Connexin 26 null mice exhibit spiral ganglion degeneration that can be blocked by BDNF gene therapy.
Abstract Mutations in the connexin 26 gene (GJB2) are the most common genetic cause of deafness, leading to congenital bilateral non-syndromic sensorineural hearing loss. Here we report the generation of a mouse model for a connexin 26 (Cx26) mutation, in which cre-Sox10 drives excision of the Cx26 gene from non-sensory cells flanking the auditory epithelium. We determined that these conditional knockout mice, designated Gjb2-CKO, have a severe hearing loss. Immunocytochemistry of the auditory epithelium confirmed absence of Cx26 in the non-sensory cells. Histology of the organ of Corti and the spiral ganglion neu...
Source: Hearing Research - December 12, 2013 Category: Audiology Authors: Takada Y, Beyer LA, Swiderski DL, O'Neal AL, Prieskorn DM, Shivatzki S, Avraham KB, Raphael Y Tags: Hear Res Source Type: research

Expression patterns of atrial natriuretic peptide and its receptors within the cochlear spiral ganglion of the postnatal rat.
Abstract The spiral ganglion, which is primarily composed of spiral ganglion neurons and satellite glial cells, transmits auditory information from sensory hair cells to the central nervous system. Atrial natriuretic peptide (ANP), acting through specific receptors, is a regulatory peptide required for a variety of cardiac, neuronal and glial functions. Although previous studies have provided direct evidence for the presence of ANP and its functional receptors (NPR-A and NPR-C) in the inner ear, their presence within the cochlear spiral ganglion and their regulatory roles during auditory neurotransmission and deve...
Source: Hearing Research - December 11, 2013 Category: Audiology Authors: Sun F, Zhou K, Wang SJ, Liang PF, Zhu MZ, Qiu JH Tags: Hear Res Source Type: research

The effects of noise vocoding on speech quality perception.
This study quantifies the effects of TFS randomization through noise vocoding on the perception of speech quality by parametrically varying the amount of original TFS available above 1500Hz. The two research aims were: 1) to establish the role of TFS in quality perception, and 2) to determine if the role of TFS in quality perception differs between subjects with normal hearing and subjects with sensorineural hearing loss. Ratings were obtained from 20 subjects (10 with normal hearing and 10 with hearing loss) using an 11-point quality scale. Stimuli were processed in three different ways: 1) A 32-channel noise-excited voco...
Source: Hearing Research - December 11, 2013 Category: Audiology Authors: Anderson MC, Arehart KH, Kates JM Tags: Hear Res Source Type: research