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Glutamate is down-regulated and tinnitus loudness-levels decreased following rTMS over auditory cortex of the left hemisphere: A prospective randomized single-blinded sham-controlled cross-over study.
Abstract Using a prospective randomized single-blinded sham-controlled cross-over design, we studied the efficacy of low frequency (1-Hz) repetitive transcranial magnetic stimulation (rTMS) over auditory cortex of the left temporal lobe as an experimental treatment modality for noise-induced tinnitus. Pre/post outcome measures for sham vs. active rTMS conditions included differential changes in tinnitus loudness, self-perceived changes in the Tinnitus Handicap Questionnaire (THQ), and neurochemical changes of brain metabolite concentrations using single voxel proton magnetic resonance spectroscopy ((1)H-MRS) obtai...
Source: Hearing Research - November 14, 2017 Category: Audiology Authors: Cacace AT, Hu J, Romero S, Xuan Y, Burkard RF, Tyler RS Tags: Hear Res Source Type: research

Effects of middle ear quasi-static stiffness on sound transmission quantified by a novel 3-axis optical force sensor.
This study investigates how middle ear transfer function is affected by stapes quasi-static stiffness of the ossicular chain. The stiffness of the middle ear is induced by a) using a novel fiber-optic 3-axis force sensor to quantify the quasi-static stiffness of the middle ear, and b) by artificial reduction of stapes mobility due to drying of the middle ear. METHODS: Middle ear transfer function, defined as the ratio of the stapes footplate velocity versus the ear canal sound pressure, was measured with a single point LDV in two conditions. First, a controlled palpation force was applied at the stapes head in two in-...
Source: Hearing Research - November 10, 2017 Category: Audiology Authors: Dobrev I, Sim JH, Aqtashi B, Huber AM, Linder T, Röösli C Tags: Hear Res Source Type: research

Performance of the Tinnitus Functional Index as a diagnostic instrument in a UK clinical population.
CONCLUSION: The TFI was confirmed to cover multiple symptom domains, measuring a multi-domain construct of tinnitus, and satisfies a range of psychometric requirements for a good clinical measure, including having excellent reliability, stability over time and sensitivity to individual differences in tinnitus severity. However, a modified seven-factor structure without the Auditory subscale (TFI-22) is recommended for calculating a global composite score for UK patients. Using patients' experience and Receiver Operator Characteristic analysis, a grading system was presented which identifies the distinct grades of tinnitus ...
Source: Hearing Research - November 9, 2017 Category: Audiology Authors: Fackrell K, Hall DA, Barry JG, Hoare DJ Tags: Hear Res Source Type: research

Development of the head, pinnae, and acoustical cues to sound location in a precocial species, the guinea pig (Cavia porcellus).
Abstract The morphology of the head and pinna shape the spatial and frequency dependence of sound propagation that give rise to the acoustic cues to sound source location. During early development, the physical dimensions of the head and pinna increase rapidly. Thus, the binaural (interaural time and level differences, ITD and ILD) and monaural (spectral shape) cues are also hypothesized to change rapidly. Complex interactions between the size and shape of the head and pinna limit the accuracy of simple acoustical models (e.g. spherical) and necessitate empirical measurements. Here, we measured the cues to locatio...
Source: Hearing Research - November 1, 2017 Category: Audiology Authors: Anbuhl KL, Benichoux V, Greene NT, Brown AD, Tollin DJ Tags: Hear Res Source Type: research

Plasticity in the auditory system.
Abstract Over the last 30 years a wide range of manipulations of auditory input and experience have been shown to result in plasticity in auditory cortical and subcortical structures. The time course of plasticity ranges from very rapid stimulus-specific adaptation to longer-term changes associated with, for example, partial hearing loss or perceptual learning. Evidence for plasticity as a consequence of these and a range of other manipulations of auditory input and/or its significance is reviewed, with an emphasis on plasticity in adults and in the auditory cortex. The nature of the changes in auditory cortex ass...
Source: Hearing Research - October 31, 2017 Category: Audiology Authors: Irvine DRF Tags: Hear Res Source Type: research

Effects of the cannabinoid CB1 agonist ACEA on salicylate ototoxicity, hyperacusis and tinnitus in guinea pigs.
Abstract Cannabinoids have been suggested as a therapeutic target for a variety of brain disorders. Despite the presence of their receptors throughout the auditory system, little is known about how cannabinoids affect auditory function. We sought to determine whether administration of arachidonyl-2'-chloroethylamide (ACEA), a highly-selective CB1 agonist, could attenuate a variety of auditory effects caused by prior administration of salicylate, and potentially treat tinnitus. We recorded cortical resting-state activity, auditory-evoked cortical activity and auditory brainstem responses (ABRs), from chronically-im...
Source: Hearing Research - October 31, 2017 Category: Audiology Authors: Berger JI, Coomber B, Hill S, Alexander SPH, Owen W, Palmer AR, Wallace MN Tags: Hear Res Source Type: research

The absence of resting-state high-gamma cross-frequency coupling in patients with tinnitus.
Abstract Tinnitus is a psychoacoustic phantom perception of currently unknown neuropathology. Despite a growing number of post-stimulus tinnitus studies, uncertainty still exists regarding the neural signature of tinnitus in the resting-state brain. In the present study, we used high-gamma cross-frequency coupling and a Granger causality analysis to evaluate resting-state electroencephalographic (EEG) data in healthy participants and patients with tinnitus. Patients with tinnitus lacked robust frontal delta-phase/central high-gamma-amplitude coupling that was otherwise clearly observed in healthy participants. Sin...
Source: Hearing Research - October 30, 2017 Category: Audiology Authors: Ahn MH, Hong SK, Min BK Tags: Hear Res Source Type: research

Cannula-based drug delivery to the guinea pig round window causes a lasting hearing loss that may be temporarily mitigated by BDNF.
This study determined the effect on hearing of placing a drug-delivery microcatheter on to the round window, and delivering either artificial perilymph (AP) or brain-derived neurotrophic factor (BDNF) via this catheter with a mini-osmotic pump. Auditory brainstem responses (ABRs) were monitored for 4 months after surgery, while the AP or BDNF was administered for the first month. The presence of the microcatheter - whether dry or when delivering AP or BDNF for 4 weeks - was associated with an increase in ABR thresholds of up to 15 dB, 16 weeks after implantation. This threshold shift was, in part, delayed by the deliv...
Source: Hearing Research - October 28, 2017 Category: Audiology Authors: Sale PJP, Uschakov A, Saief T, Rowe DP, Abbott CJ, Luu CD, Hampson AJ, O'Leary SJ, Sly DJ Tags: Hear Res Source Type: research

The effect of illusionary perception on mismatch negativity (MMN): An electroencephalography study.
Abstract Mismatch negativity (MMN) is a unique brain response elicited by any discernible change of features in a tone sequence. Although the occurrence of MMN is dependent upon the difference of a stimulus parameter, such as frequency or intensity, recent studies have suggested that MMN occurs as a result of a comparison between an internal representation created by perception and an incoming tone. The present study aimed to investigate MMN occurs based upon the physical properties of stimuli or as a result of the perception of the scale illusion. A scale illusion occurs during presentation of ascending and desce...
Source: Hearing Research - October 17, 2017 Category: Audiology Authors: Ono K, Yamasaki D, Altmann CF, Mima T Tags: Hear Res Source Type: research

Tinnitus with a normal audiogram: Role of high-frequency sensitivity and reanalysis of brainstem-response measures to avoid audiometric over-matching.
PMID: 29056432 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - October 14, 2017 Category: Audiology Authors: Guest H, Munro KJ, Plack CJ Tags: Hear Res Source Type: research

Auditory sequential accumulation of spectral information.
Abstract In many listening situations, information about the spectral content of a target sound may be distributed over time, and estimating the target spectrum requires efficient sequential processing. Listeners' ability to estimate the spectrum of a random-frequency, six-tone complex was investigated and the spectral content of the complex was revealed using a sequence of bursts. Whether each of the six tones was presented within each burst was determined at random according to a presentation probability. In separate conditions, the presentation probabilities (p) ranged from 0.2 to 1, the total number of bursts ...
Source: Hearing Research - October 11, 2017 Category: Audiology Authors: Shen Y Tags: Hear Res Source Type: research

An operating principle of the turtle utricle to detect wide dynamic range.
Abstract The utricle encodes both static information such as head orientation, and dynamic information such as vibrations. It is not well understood how the utricle can encode both static and dynamic information for a wide dynamic range (from 2 times the gravitational acceleration; from DC to > 1000 Hz vibrations). Using computational models of the hair cells in the turtle utricle, this study presents an explanation on how the turtle utricle encodes stimulations over such a wide dynamic range. Two hair bundles were modeled using the finite element method-one representing the striolar hair cell (C...
Source: Hearing Research - October 9, 2017 Category: Audiology Authors: Nam JH Tags: Hear Res Source Type: research

Corrigendum to "Place dependent stimulation rates improve pitch perception in cochlear implantees with single-sided deafness" [Hear. Res. 339 (2016) 94-103].
Corrigendum to "Place dependent stimulation rates improve pitch perception in cochlear implantees with single-sided deafness" [Hear. Res. 339 (2016) 94-103]. Hear Res. 2017 Oct;354:109 Authors: Rader T, Döge J, Adel Y, Weissgerber T, Baumann U PMID: 28958391 [PubMed - in process] (Source: Hearing Research)
Source: Hearing Research - September 30, 2017 Category: Audiology Authors: Rader T, Döge J, Adel Y, Weissgerber T, Baumann U Tags: Hear Res Source Type: research

Diversity of bilateral synaptic assemblies for binaural computation in midbrain single neurons.
This study examines the bilateral synaptic assemblies and binaural computation (or integration) in the central nucleus of the inferior colliculus (ICc) of the auditory midbrain, a key convergent center. Using in-vivo whole-cell patch-clamp, the excitatory and inhibitory postsynaptic potentials (EPSPs/IPSPs) of single ICc neurons to contralateral, ipsilateral and bilateral stimulation were recorded. According to the contralateral and ipsilateral EPSP/IPSP, 7 types of bilateral synaptic assemblies were identified. These include EPSP-EPSP (EE), E-IPSP (EI), E-no response (EO), II, IE, IO and complex-mode (CM) neurons. The CM ...
Source: Hearing Research - September 18, 2017 Category: Audiology Authors: He N, Kong L, Lin T, Wang S, Liu X, Qi J, Yan J Tags: Hear Res Source Type: research

Standard-interval size affects interval-discrimination thresholds for pure-tone melodic pitch intervals.
Abstract Our ability to discriminate between pitch intervals of different sizes is not only an important aspect of speech and music perception, but also a useful means of evaluating higher-level pitch perception. The current study examined how pitch-interval discrimination was affected by the size of the intervals being compared, and by musical training. Using an adaptive procedure, pitch-interval discrimination thresholds were measured for sequentially presented pure-tone intervals with standard intervals of 1 semitone (minor second), 6 semitones (the tri-tone), and 7 semitones (perfect fifth). Listeners were cla...
Source: Hearing Research - September 18, 2017 Category: Audiology Authors: McClaskey CM Tags: Hear Res Source Type: research

Language experience-dependent advantage in pitch representation in the auditory cortex is limited to favorable signal-to-noise ratios.
Abstract Long-term experience enhances neural representation of temporal attributes of pitch in the brainstem and auditory cortex in favorable listening conditions. Herein we examine whether cortical pitch mechanisms shaped by language experience are more resilient to degradation in background noise, and exhibit greater binaural release from masking (BRM). Cortical pitch responses (CPR) were recorded from Mandarin- and English-speaking natives using a Mandarin word exhibiting a high rising pitch (/yi(2)/). Stimuli were presented diotically in Quiet, and in noise at +5, and 0 dB SNR. CPRs were also record...
Source: Hearing Research - September 14, 2017 Category: Audiology Authors: Suresh CH, Krishnan A, Gandour JT Tags: Hear Res Source Type: research

Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex.
Abstract Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what e...
Source: Hearing Research - September 11, 2017 Category: Audiology Authors: Weisz N, Lithari C Tags: Hear Res Source Type: research

Emotional recognition of dynamic facial expressions before and after cochlear implantation in adults with progressive deafness.
Abstract Visual processing has been extensively explored in deaf subjects in the context of verbal communication, through the assessment of speech reading and sign language abilities. However, little is known about visual emotional processing in adult progressive deafness, and after cochlear implantation. The goal of our study was thus to assess the influence of acquired post-lingual progressive deafness on the recognition of dynamic facial emotions that were selected to express canonical fear, happiness, sadness, and anger. A total of 23 adults with post-lingual deafness separated into two groups; those assessed ...
Source: Hearing Research - August 31, 2017 Category: Audiology Authors: Ambert-Dahan E, Giraud AL, Mecheri H, Sterkers O, Mosnier I, Samson S Tags: Hear Res Source Type: research

Effects of attention on the speech reception threshold and pupil response of people with impaired and normal hearing.
Abstract For people with hearing difficulties, following a conversation in a noisy environment requires substantial cognitive processing, which is often perceived as effortful. Recent studies with normal hearing (NH) listeners showed that the pupil dilation response, a measure of cognitive processing load, is affected by 'attention related' processes. How these processes affect the pupil dilation response for hearing impaired (HI) listeners remains unknown. Therefore, the current study investigated the effect of auditory attention on various pupil response parameters for 15 NH adults (median age 51 yrs.) and 15 ad...
Source: Hearing Research - August 30, 2017 Category: Audiology Authors: Koelewijn T, Versfeld NJ, Kramer SE Tags: Hear Res Source Type: research

The effect of blast overpressure on the mechanical properties of a chinchilla tympanic membrane.
Abstract The rupture of tympanic membrane (TM) has long been viewed as an indicator of blast injury, especially for hearing loss. However, little is known about damage to the TM caused by blast with pressure lower than the rupture threshold. In this paper, we present our study on the effect of blast overpressure on the static mechanical properties of TM. Chinchilla was used as the animal model and exposed to multiple blasts with pressures lower than the rupture threshold of the TM. Using a micro-fringe projection method, we observed the alteration of the static mechanical properties of post-blast chinchilla's TMs ...
Source: Hearing Research - August 18, 2017 Category: Audiology Authors: Liang J, Yokell ZA, Nakmaili DU, Gan RZ, Lu H Tags: Hear Res Source Type: research

Strain-specific differences in the development of neuronal excitability in the mouse ventral nucleus of the trapezoid body.
Abstract This investigation compared the development of neuronal excitability in the ventral nucleus of the trapezoid body (VNTB) between two strains of mice with differing progression rates for age-related hearing loss. In contrast to CBA/Ca (CBA) mice, the C57BL/6J (C57) strain are subject to hearing loss from a younger age and are more prone to damage from sound over-exposure. Higher firing rates in the medial olivocochlear system (MOC) are associated with protection from loud sounds and these cells are located in the VNTB. We postulated that reduced neuronal firing of the MOC in C57 mice could contribute to he...
Source: Hearing Research - August 18, 2017 Category: Audiology Authors: Sinclair JL, Barnes-Davies M, Kopp-Scheinpflug C, Forsythe ID Tags: Hear Res Source Type: research

No auditory experience, no tinnitus: Lessons from subjects with  congenital- and acquired single-sided deafness.
This study enrolled 20 subjects with congenital SSD and 44 subjects with acquired SSD and examined the presence and characteristics of tinnitus in the groups. None of the 20 subjects with congenital SSD perceived tinnitus on the affected side, whereas 30 of 44 subjects with acquired SSD experienced tinnitus on the affected side. Additionally, there were significant positive correlations between tinnitus characteristics and the audiometric characteristics of the SSD. In accordance with the findings of the recent animal study, tinnitus was absent in subjects with congenital SSD, but relatively frequent in subjects with acqui...
Source: Hearing Research - August 15, 2017 Category: Audiology Authors: Lee SY, Nam DW, Koo JW, De Ridder D, Vanneste S, Song JJ Tags: Hear Res Source Type: research

Improved middle-ear soft-tissue visualization using synchrotron radiation phase-contrast imaging.
Abstract High resolution images are used as a basis for finite-element modeling of the middle-ear structures to study their biomechanical function. Commonly used imaging techniques such as micro-computed tomography (CT) and optical microscopy require extensive sample preparation, processing or staining using contrast agents to achieve sufficient soft-tissue contrast. We compare imaging of middle-ear structures in unstained, non-decalcified human temporal bones using conventional absorption-contrast micro-CT and using synchrotron radiation phase-contrast imaging (SR-PCI). Four cadaveric temporal bones were imaged u...
Source: Hearing Research - August 5, 2017 Category: Audiology Authors: Elfarnawany M, Rohani SA, Ghomashchi S, Allen DG, Zhu N, Agrawal SK, Ladak HM Tags: Hear Res Source Type: research

Speech reception with different bilateral directional processing schemes: Influence of binaural hearing, audiometric asymmetry, and acoustic scenario.
Abstract Hearing aid (HA) users can differ markedly in their benefit from directional processing (or beamforming) algorithms. The current study therefore investigated candidacy for different bilateral directional processing schemes. Groups of elderly listeners with symmetric (N = 20) or asymmetric (N = 19) hearing thresholds for frequencies below 2 kHz, a large spread in the binaural intelligibility level difference (BILD), and no difference in age, overall degree of hearing loss, or performance on a measure of selective attention took part. Aided speech reception was measured using virtua...
Source: Hearing Research - July 29, 2017 Category: Audiology Authors: Neher T, Wagener KC, Latzel M Tags: Hear Res Source Type: research

Otoliths - Accelerometer and seismometer; Implications in Vestibular Evoked Myogenic Potential (VEMP).
Abstract Vestibular otolithic organs are recognized as transducers of head acceleration and they function as such up to their corner frequency or undamped natural frequency. It is well recognized that these organs respond to frequencies above their corner frequency up to the 2-3 kHz range (Curthoys et al., 2016). A mechanics model for the transduction of these organs is developed that predicts the response below the undamped natural frequency as an accelerometer and above that frequency as a seismometer. The model is converted to a transfer function using hair cell bundle deflection. Measured threshold a...
Source: Hearing Research - July 27, 2017 Category: Audiology Authors: Grant W, Curthoys I Tags: Hear Res Source Type: research

Changes of metabolism and functional connectivity in late-onset deafness: Evidence from cerebral (18)F-FDG-PET.
Abstract Hearing loss is known to impact brain function. The aim of this study was to characterize cerebral metabolic Positron Emission Tomography (PET) changes in elderly patients fulfilling criteria for cochlear implant and investigate the impact of hearing loss on functional connectivity. Statistical Parametric Mapping-T-scores-maps comparisons of (18)F-FDG-PET of 27 elderly patients fulfilling criteria for cochlear implant for hearing loss (best-aided speech intelligibility lower or equal to 50%) and 27 matched healthy subjects (p 
Source: Hearing Research - July 27, 2017 Category: Audiology Authors: Verger A, Roman S, Chaudat RM, Felician O, Ceccaldi M, Didic M, Guedj E Tags: Hear Res Source Type: research

Detecting temporal changes in acoustic scenes: The variable benefit of selective attention.
Abstract Four experiments investigated change detection in acoustic scenes consisting of a sum of five amplitude-modulated pure tones. As the tones were about 0.7 octave apart and were amplitude-modulated with different frequencies (in the range 2-32 Hz), they were perceived as separate streams. Listeners had to detect a change in the frequency (experiments 1 and 2) or the shape (experiments 3 and 4) of the modulation of one of the five tones, in the presence of an informative cue orienting selective attention either before the scene (pre-cue) or after it (post-cue). The changes left intensity unchanged and w...
Source: Hearing Research - July 27, 2017 Category: Audiology Authors: Demany L, Bayle Y, Puginier E, Semal C Tags: Hear Res Source Type: research

Declining and fluctuating prevalence values of hearing impairment in 18-year old Swedish men during three decades.
CONCLUSIONS: The most important observation was a decrease of HFHI 35-40 dB HL by 52% percent and of HFHI ≥45 dB HL by 71% between the years 1971 and 2004. The prevalence of HFHI 25-30 dB HL in young Swedish males fluctuated over a period of 33 years. Possible reasons for these trends and variations are discussed. PMID: 28759744 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 23, 2017 Category: Audiology Authors: Muhr P, Johnson AC, Rosenhall U Tags: Hear Res Source Type: research

Noise exposure alters long-term neural firing rates and synchrony in primary auditory and rostral belt cortices following bimodal stimulation.
Abstract We previously demonstrated that bimodal stimulation (spinal trigeminal nucleus [Sp5] paired with best frequency tone) altered neural tone-evoked and spontaneous firing rates (SFRs) in primary auditory cortex (A1) 15 min after pairing in guinea pigs with and without noise-induced tinnitus. Neural responses were enhanced (+10 ms) or suppressed (0 ms) based on the bimodal pairing interval. Here we investigated whether bimodal stimulation leads to long-term (up to 2 h) changes in tone-evoked and SFRs and neural synchrony (correlate of tinnitus) and if the long-term bimodal effects are alte...
Source: Hearing Research - July 13, 2017 Category: Audiology Authors: Takacs JD, Forrest TJ, Basura GJ Tags: Hear Res Source Type: research

Noise-induced cochlear synaptopathy in rhesus monkeys (Macaca mulatta).
Abstract Cochlear synaptopathy can result from various insults, including acoustic trauma, aging, ototoxicity, or chronic conductive hearing loss. For example, moderate noise exposure in mice can destroy up to ∼50% of synapses between auditory nerve fibers (ANFs) and inner hair cells (IHCs) without affecting outer hair cells (OHCs) or thresholds, because the synaptopathy occurs first in high-threshold ANFs. However, the fiber loss likely impairs temporal processing and hearing-in-noise, a classic complaint of those with sensorineural hearing loss. Non-human primates appear to be less vulnerable to noise-induce...
Source: Hearing Research - July 8, 2017 Category: Audiology Authors: Valero MD, Burton JA, Hauser SN, Hackett TA, Ramachandran R, Liberman MC Tags: Hear Res Source Type: research

Noise-induced hearing loss induces loudness intolerance in a rat Active Sound Avoidance Paradigm (ASAP).
Abstract Hyperacusis is a loudness hypersensitivity disorder in which moderate-intensity sounds are perceived as extremely loud, aversive and/or painful. To assess the aversive nature of sounds, we developed an Active Sound Avoidance Paradigm (ASAP) in which rats altered their place preference in a Light/Dark shuttle box in response to sound. When no sound (NS) was present, rats spent more than 95% of the time in the Dark Box versus the transparent Light Box. However, when a 60 or 90 dB SPL noise (2-20 kHz, 2-8 kHz, or 16-20 kHz bandwidth) was presented in the Dark Box, the rats'' preference fo...
Source: Hearing Research - July 8, 2017 Category: Audiology Authors: Manohar S, Spoth J, Radziwon K, Auerbach BD, Salvi R Tags: Hear Res Source Type: research

Medial geniculate neurons show diverse effects in response to electrical stimulation of prefrontal cortex.
Abstract Phantom perceptions have been proposed to arise due to dysfunctional sensory gating at the level of the thalamus. Recently, it has been suggested that tinnitus, a phantom perception of sound, may arise from altered cortico-limbic circuitry and its connection with the auditory thalamus, the medial geniculate nucleus (MGN). Indeed, some elements of this cortico-limbic circuitry, such as the prefrontal cortex (PFC), as well as elements of the auditory pathway, have been shown to be altered in humans with tinnitus. However, the functional connectivity between PFC and MGN has not yet been explored. We therefor...
Source: Hearing Research - July 8, 2017 Category: Audiology Authors: Barry KM, Robertson D, Mulders WHAM Tags: Hear Res Source Type: research

Synaptic distribution and plasticity in primary auditory cortex (A1) exhibits laminar and cell-specific changes in the deaf.
Abstract The processing sequence through primary auditory cortex (A1) is impaired by deafness as evidenced by reduced neuronal activation in A1 of cochlear-implanted deaf cats. Such a loss of neuronal excitation should be manifest as changes in excitatory synaptic number and/or size, for which the post-synaptic correlate is the dendritic spine. Therefore, the present study sought evidence for this functional disruption using Golgi-Cox/light microscopic techniques that examined spine-bearing neurons and their dendritic spine features across all laminae in A1 of early-deaf (ototoxic lesion 16 months) and hearing cat...
Source: Hearing Research - July 1, 2017 Category: Audiology Authors: Clemo HR, Lomber SG, Meredith MA Tags: Hear Res Source Type: research

Simultaneous masking between electric and acoustic stimulation in cochlear implant users with residual low-frequency hearing.
ueira W Abstract Ipsilateral electric-acoustic stimulation (EAS) is becoming increasingly important in cochlear implant (CI) treatment. Improvements in electrode designs and surgical techniques have contributed to improved hearing preservation during implantation. Consequently, CI implantation criteria have been expanded toward people with significant residual low-frequency hearing, who may benefit from the combined use of both the electric and acoustic stimulation in the same ear. However, only few studies have investigated the mutual interaction between electric and acoustic stimulation modalities. This work cha...
Source: Hearing Research - June 30, 2017 Category: Audiology Authors: Krüger B, Büchner A, Nogueira W Tags: Hear Res Source Type: research

Paraflocculus plays a role in salicylate-induced tinnitus.
Abstract Tinnitus impairs quality of life of about 1-2% of the whole population. In most severe situation, tinnitus may cause social isolation, depression and suicide. Drug treatments for tinnitus are generally ineffective, and the mechanisms of tinnitus are still undetermined. Accumulating evidence suggests that tinnitus is related to changes of widespread brain networks. Recent studies propose that paraflocculus (PFL), which is indirectly connected to various cortical regions, may be a gating zone of tinnitus. So we examined the electrophysiological changes and neurotransmitter alterations of the PFL in a rat mo...
Source: Hearing Research - June 29, 2017 Category: Audiology Authors: Du Y, Liu J, Jiang Q, Duan Q, Mao L, Ma F Tags: Hear Res Source Type: research

A comparative study of MED-EL FMT attachment to the long process of the incus in intact middle ears and its attachment to disarticulated stapes head.
Abstract The Vibrant Soundbridge(©) (VSB) active middle-ear implant provides an effective treatment for mild-to-severe sensorineural hearing loss in the case of normal middle ear anatomy and mixed hearing loss in middle ear malformation. The VSB floating mass transducer (FMT), with proper couplers, can be installed on various structures of the ossicular chain, e.g., the short and long process of the incus, the stapes head, and the stapes footplate. A long process (LP) coupler is most commonly used for FMT attachment to the long process of the incus with intact ossicular chain, while CliP and Bell couplers are...
Source: Hearing Research - June 23, 2017 Category: Audiology Authors: Chen T, Ren LJ, Yin DM, Li J, Yang L, Dai PD, Zhang TY Tags: Hear Res Source Type: research

Contralateral routing of signals disrupts monaural level and spectral cues to sound localisation on the horizontal plane.
CONCLUSIONS: The re-routing of sounds can restrict access to the monaural cues that provide a basis for determining sound location in the horizontal plane. Perhaps encouragingly, the results suggest that both monaural level and spectral cues may not be disrupted entirely by signal re-routing and that it may still be possible to reliably identify sounds originating on the hearing side. PMID: 28666702 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 21, 2017 Category: Audiology Authors: Pedley AJ, Kitterick PT Tags: Hear Res Source Type: research

Neural representations of concurrent sounds with overlapping spectra in rat inferior colliculus: Comparisons between temporal-fine structure and envelope.
In this study, we investigated the neural representation of two uncorrelated narrowband noises that shared the identical spectrum in the rat inferior colliculus (IC) using frequency-following-response (FFR) recordings, when the ITD for each noise stimulus was manipulated. The results of this study showed that recorded FFRs exhibited two distinctive components: the fast-varying temporal fine structure (TFS) component (FFRTFS) and the slow-varying envelope component (FFRENV). When a single narrowband noise was presented alone, the FFRTFS, but not the FFRENV, was sensitive to ITDs. When two narrowband noises were presented si...
Source: Hearing Research - June 17, 2017 Category: Audiology Authors: Luo L, Wang Q, Li L Tags: Hear Res Source Type: research

Characterization of the superior olivary complex of Canis lupus domesticus.
Kulesza RJ Abstract The superior olivary complex (SOC) is a collection of brainstem auditory nuclei which play essential roles in the localization of sound sources, temporal coding of vocalizations and descending modulation of the cochlea. Notwithstanding, the SOC nuclei vary considerably between species in accordance with the auditory needs of the animal. The canine SOC was subjected to anatomical and physiological examination nearly 50 years ago and was then virtually forgotten. Herein, we aimed to characterize the nuclei of the canine SOC using quantitative morphometrics, estimation of neuronal number, histoch...
Source: Hearing Research - June 15, 2017 Category: Audiology Authors: Fech T, Calderón-Garcidueñas L, Kulesza RJ Tags: Hear Res Source Type: research

Effect of stimulus level on the temporal response properties of the auditory nerve in cochlear implants.
Abstract Electrically evoked compound action potentials (ECAPs) have been used to examine temporal response patterns of the auditory nerve in cochlear implant (CI) recipients. ECAP responses to individual pulses in a pulse train vary across stimulation rates for individual CI users. For very slow rates, auditory neurons have ample time to discharge, recover, and respond to each pulse in the train. As the pulse rate increases, an alternating ECAP-amplitude pattern occurs. As the stimulation rate increases further, the alternating pattern eventually ceases and the overall ECAP amplitudes are diminished, yielding a r...
Source: Hearing Research - June 13, 2017 Category: Audiology Authors: Hughes ML, Laurello SA Tags: Hear Res Source Type: research

Altered attentional filters in subjects with graded levels of sensorineural hearing loss.
Abstract Near-threshold tones (targets) in noise that are preceded by cues of the same frequency or occur with a high probability are detected better than tones of other frequencies that may occur with a lower probability (probes); the better detection of targets than probes defines the attentional filter. We measured attentional filters using a cued probe-signal procedure with a two-interval forced-choice (2IFC) method in normal-hearing subjects (N = 15) and subjects with sensorineural hearing loss (SNHL; N = 14) with a range of hearing levels. Attentional filters were altered in SNHL subjects...
Source: Hearing Research - June 10, 2017 Category: Audiology Authors: Bester CW, Robertson D, Taljaard D, Hammond G Tags: Hear Res Source Type: research

Sheep as a large animal ear model: Middle-ear ossicular velocities and intracochlear sound pressure.
This study investigated the middle-ear ossicular velocities and intracochlear sound pressure (ICSP) in sheep temporal bones, with the aim of characterizing the sheep as an experimental model for implantable hearing devices. Measurements were made on fresh sheep temporal bones. Velocity responses of the middle ear ossicles at the umbo, long process of the incus and stapes footplate were measured in the frequency range of 0.25-8 kHz using a laser Doppler vibrometer system. Results were normalized by the corresponding sound pressure level in the external ear canal (PEC). Sequentially, ICSPs at the scala vestibuli and tym...
Source: Hearing Research - June 7, 2017 Category: Audiology Authors: Péus D, Dobrev I, Prochazka L, Thoele K, Dalbert A, Boss A, Newcomb N, Probst R, Röösli C, Sim JH, Huber A, Pfiffner F Tags: Hear Res Source Type: research

Editorial: Auditory injury - A military perspective.
PMID: 28526261 [PubMed - in process] (Source: Hearing Research)
Source: Hearing Research - May 21, 2017 Category: Audiology Authors: Yankaskas K, Hammill T, Packer M, Zuo J Tags: Hear Res Source Type: research

Peripheral hearing loss reduces the ability of children to direct selective attention during multi-talker listening.
We examined the ability of hearing-impaired children to direct auditory attention to a voice of interest (based on the talker's spatial location or gender) in the presence of a common form of background noise: the voices of competing talkers (i.e. during multi-talker, or "Cocktail Party" listening). We measured brain activity using electro-encephalography (EEG) when children prepared to direct attention to the spatial location or gender of an upcoming target talker who spoke in a mixture of three talkers. Compared to normally-hearing children, hearing-impaired children showed significantly less evidence of prepar...
Source: Hearing Research - May 10, 2017 Category: Audiology Authors: Holmes E, Kitterick PT, Summerfield AQ Tags: Hear Res Source Type: research

Amino acid and acetylcholine chemistry in the central auditory system of young, middle-aged and old rats.
In this study, we used quantitative microchemical methods to map concentrations of amino acids, including the major neurotransmitters of the brain, in all the major central auditory structures of young (6 months), middle-aged (22 months), and old (33 months old) Fischer 344 x Brown Norway rats. In addition, some amino acid measurements were made for vestibular nuclei, and activities of choline acetyltransferase, the enzyme for acetylcholine synthesis, were mapped in the superior olive and auditory cortex. In old, as compared to young, rats, glutamate concentrations were lower throughout central auditory regions. Aspartate ...
Source: Hearing Research - May 4, 2017 Category: Audiology Authors: Godfrey DA, Chen K, O'Toole TR, Mustapha AIAA Tags: Hear Res Source Type: research

Response to letter: Psychometric properties of the Tinnitus Functional Index (TFI): Assessment in a UK research volunteer population.
PMID: 28495019 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 4, 2017 Category: Audiology Authors: Fackrell K, Hall DA, Barry JG, Hoare DJ Tags: Hear Res Source Type: research

Effect of efferent activation on binaural frequency selectivity.
Abstract Binaural notched-noise experiments indicate a reduced frequency selectivity of the binaural system compared to monaural processing. The present study investigates how auditory efferent activation (via the medial olivocochlear system) affects binaural frequency selectivity in normal-hearing listeners. Thresholds were measured for a 1-kHz signal embedded in a diotic notched-noise masker for various notch widths. The signal was either presented in phase (diotic) or in antiphase (dichotic), gated with the noise. Stimulus duration was 25 ms, in order to avoid efferent activation due to the masker or the s...
Source: Hearing Research - May 2, 2017 Category: Audiology Authors: Verhey JL, Kordus M, Drga V, Yasin I Tags: Hear Res Source Type: research

Chronic tinnitus and unipolar brush cell alterations in the cerebellum and dorsal cochlear nucleus.
Abstract Animal model research has shown that the central features of tinnitus, the perception of sound without an acoustic correlate, include elevated spontaneous and stimulus-driven activity, enhanced burst-mode firing, decreased variance of inter-spike intervals, and distortion of tonotopic frequency representation. Less well documented are cell-specific correlates of tinnitus. Unipolar brush cell (UBC) alterations in animals with psychophysical evidence of tinnitus has recently been reported. UBCs are glutamatergic interneurons that appear to function as local-circuit signal amplifiers. UBCs are abundant in th...
Source: Hearing Research - May 2, 2017 Category: Audiology Authors: Brozoski T, Brozoski D, Wisner K, Bauer C Tags: Hear Res Source Type: research

Salicylate-induced hyperacusis in rats: Dose- and frequency-dependent effects.
Abstract The use of auditory reaction time is a reliable measure of loudness perception in both animals and humans with reaction times (RT) decreasing with increasing stimulus intensity. Since abnormal loudness perception is a common feature of hyperacusis, a potentially debilitating auditory disorder in which moderate-intensity sounds are perceived as uncomfortable or painfully loud, we used RT measures to assess rats for salicylate-induced hyperacusis. A previous study using an operant conditioning RT procedure found that high-dose sodium salicylate (SS) induced hyperacusis-like behavior, i.e., faster than norma...
Source: Hearing Research - April 27, 2017 Category: Audiology Authors: Radziwon K, Holfoth D, Lindner J, Kaier-Green Z, Bowler R, Urban M, Salvi R Tags: Hear Res Source Type: research

Effects of noise-induced hearing loss on parvalbumin and perineuronal net expression in the mouse primary auditory cortex.
Abstract Noise induced hearing loss is associated with increased excitability in the central auditory system but the cellular correlates of such changes remain to be characterized. Here we tested the hypothesis that noise-induced hearing loss causes deterioration of perineuronal nets (PNNs) in the auditory cortex of mice. PNNs are specialized extracellular matrix components that commonly enwrap cortical parvalbumin (PV) containing GABAergic interneurons. Compared to somatosensory and visual cortex, relatively less is known about PV/PNN expression patterns in the primary auditory cortex (A1). Whether changes to cor...
Source: Hearing Research - April 27, 2017 Category: Audiology Authors: Nguyen A, Khaleel HM, Razak KA Tags: Hear Res Source Type: research