Human frequency following responses to iterated rippled noise with positive and negative gain: Differential sensitivity to waveform envelope and temporal fine-structure.
Abstract The perceived pitch of iterated rippled noise (IRN) with negative gain (IRNn) is an octave lower than that of IRN with positive gain (IRNp). IRNp and IRNn have identical waveform envelopes (ENV), but differing stimulus waveform fine structure (TFS), which likely accounts for this perceived pitch difference. Here, we examine whether differences in the temporal pattern of phase-locked activity reflected in the human brainstem Frequency Following Response (FFR) elicited by IRNp and IRNn can account for the differences in perceived pitch for the two stimuli. FFRs using a single onset polarity were measured in...
Source: Hearing Research - July 29, 2018 Category: Audiology Authors: Ananthakrishnan S, Krishnan A Tags: Hear Res Source Type: research

Detection of single mRNAs in individual cells of the auditory system.
Abstract Gene expression analysis is essential for understanding the rich repertoire of cellular functions. With the development of sensitive molecular tools such as single-cell RNA sequencing, extensive gene expression data can be obtained and analyzed from various tissues. Single-molecule fluorescence in situ hybridization (smFISH) has emerged as a powerful complementary tool for single-cell genomics studies because of its ability to map and quantify the spatial distributions of single mRNAs at the subcellular level in their native tissue. Here, we present a detailed method to study the copy numbers and spatial ...
Source: Hearing Research - July 29, 2018 Category: Audiology Authors: Salehi P, Nelson CN, Chen Y, Lei D, Crish SD, Nelson J, Zuo H, Bao J Tags: Hear Res Source Type: research

Age-related changes in Na, K-ATPase expression, subunit isoform selection and assembly in the stria vascularis lateral wall of mouse cochlear.
Abstract Due to the critical role of cochlear ion channels for hearing, the focus of the present study was to examine age-related changes of Na, K-ATPase (NKA) subunits in the lateral wall of mouse cochlea. We combined qRT-PCR, western blot and immunocytochemistry methodologies in order to determine gene and protein expression levels in the lateral wall of young and aged CBA/CaJ mice. Of the seven NKA subunits, only the mRNA expressions of α1, β1 and β2 subunit isoforms were detected in the lateral wall of CBA/CaJ mice. Aging was accompanied by dys-regulation of gene and protein expression of all t...
Source: Hearing Research - July 10, 2018 Category: Audiology Authors: Ding B, Walton JP, Zhu X, Frisina RD Tags: Hear Res Source Type: research

Neuroanatomical characterization of perineuronal net components in the human cochlear nucleus and superior olivary complex.
In conclusion, the present study demonstrates that PNs form a prominent extracellular structure on CN and SOC neurons in the human brain, potentially stabilizing synaptic contacts, which is in agreement with many other mammalian species. PMID: 30025262 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - July 10, 2018 Category: Audiology Authors: Weinrich L, Sonntag M, Arendt T, Morawski M Tags: Hear Res Source Type: research

Hearing preservation at low frequencies by insulin-like growth factor 1 in a guinea pig model of cochlear implantation.
In this study, the effects of IGF1 on hearing preservation were examined after cochlear implantation to a normal-hearing guinea pig model. The electrode was inserted in an atraumatic way through the round window membrane of guinea pigs with the application of a gelatin-sponge soaked with IGF1 or saline. The auditory brainstem response (ABR) was recorded pre-operatively, immediately after cochlear implantation, and 7, 14, 28, and 56 days after electrode insertion. In comparison to the control group, the IGF1-treated group showed better hearing preservation at low frequencies, 7 days after surgery. IGF1 application was effec...
Source: Hearing Research - July 6, 2018 Category: Audiology Authors: Yamahara K, Nishimura K, Ogita H, Ito J, Nakagawa T, Furuta I, Kita T, Omori K, Yamamoto N Tags: Hear Res Source Type: research

Perception of noise-vocoded tone complexes: A time domain analysis based on an auditory filterbank model.
Abstract When a wideband harmonic tone complex (wHTC) is passed through a noise vocoder, the resulting sounds can have spectra with large peak-to-valley ratios, but little or no periodicity strength in the autocorrelation functions. We measured judgments of pitch strength for normal-hearing listeners for noise-vocoded wideband harmonic tone complexes (NV-wHTCs) relative to standard and anchor stimuli. The standard was a 1-channel NV-wHTC and the anchor was either the unprocessed wHTC or an infinitely-iterated rippled noise (IIRN). Although there is variability among individuals, the magnitude judgment functions ob...
Source: Hearing Research - July 4, 2018 Category: Audiology Authors: Shofner WP, Morris H, Mills M Tags: Hear Res Source Type: research

Local drug delivery to the inner ear: Principles, practice, and future challenges.
PMID: 30006112 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 28, 2018 Category: Audiology Authors: Plontke SK, Salt AN Tags: Hear Res Source Type: research

Familiarity with social sounds alters c-Fos expression in auditory cortex and interacts with estradiol in locus coeruleus.
Abstract When a social sound category initially gains behavioral significance to an animal, plasticity events presumably enhance the ability to recognize that sound category in the future. In the context of learning natural social stimuli, neuromodulators such as norepinephrine and estrogen have been associated with experience-dependent plasticity and processing of newly salient social cues, yet continued plasticity once stimuli are familiar could disrupt the stability of sensorineural representations. Here we employed a maternal mouse model of natural sensory cortical plasticity for infant vocalizations to ask wh...
Source: Hearing Research - June 28, 2018 Category: Audiology Authors: Moreno A, Gumaste A, Adams GK, Chong KK, Nguyen M, Shepard KN, Liu RC Tags: Hear Res Source Type: research

Electric and acoustic harmonic integration predicts speech-in-noise performance in hybrid cochlear implant users.
CONCLUSIONS: We demonstrate integration of acoustic and electric information in H-CI users for complex pitch sensation. The correlation with speech scores in H-CI users might be associated with the ability to segregate a target speaker from background noise using the speaker's fundamental frequency. PMID: 29980380 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 28, 2018 Category: Audiology Authors: Bonnard D, Schwalje A, Gantz B, Choi I Tags: Hear Res Source Type: research

Neuroplastic change of cytoskeleton in inferior colliculus after auditory deafferentation.
In this study, we evaluated the dynamic status of neurofilament (NF) phosphorylation in the IC after hearing loss. We induced auditory deafferentation via unilateral or bilateral cochlear ablation in rats, aged 4 weeks. To evaluate cytoskeletal changes in neurons, we evaluated mRNA fold changes in NF heavy chain expression, non-phosphorylated NF protein fold changes using SMI-32 antibody, and the ratio of SMI-32 immunoreactive (SMI-32-ir) neurons to the total neuronal population in the IC at 4 and 12 weeks after deafness. In the bilateral deafness (BD) group, the ratios of SMI-32-ir neurons significantly increased at 4 wee...
Source: Hearing Research - June 23, 2018 Category: Audiology Authors: Han JJ, Lee HS, Park MH Tags: Hear Res Source Type: research

Microenvironmental support for cell delivery to the inner ear.
In this study, we demonstrate that MSC delivered to the inner ear of guinea pigs or to decellularized cochleae preferentially bind to areas of high heparin concentration. This presents an opportunity for modulating cell behaviour ex vivo. We evaluated the effect of carboxymethylglucose sulfate (Cacicol®), a heparan sulfate analogue on spiral ganglion cells and MSC and demonstrated support of neuronal survival and support of stem cell proliferation. PMID: 29945803 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 21, 2018 Category: Audiology Authors: Schulze J, Sasse S, Prenzler N, Staecker H, Mellott AJ, Roemer A, Durisin M, Lenarz T, Warnecke A Tags: Hear Res Source Type: research

Intracochlear pressure in response to high intensity, low frequency sounds in chinchilla.
Abstract Exposure to high intensity (blast) sounds can result in both conductive and sensorineural damage to hearing. This includes rupture of the tympanic membrane and dislocation of the middle ear ossicles, as well as damage to the inner and outer hair cells in the cochlea. A clearer understanding of how the hearing system responds to blast could help us better prevent auditory trauma, and support those who have been exposed to such sounds. Chinchillas are often used in studies of hearing due to the similarity between the chinchilla and human audiograms. The suitability of their use in research on auditory traum...
Source: Hearing Research - June 21, 2018 Category: Audiology Authors: Peacock J, Al Hussaini M, Greene NT, Tollin DJ Tags: Hear Res Source Type: research

Comorbidities of hearing loss and the implications of multimorbidity for audiological care.
Abstract With increasing age, the risk of developing chronic health conditions also increases, and many older people suffer from multiple co-existing health conditions, i.e., multimorbidity. One common health condition at older age is hearing loss (HL). The current article reflects on the implications for audiological care, when HL is one of several health conditions in a multimorbidity. An overview of health conditions often co-existing with HL, so called comorbidities, is provided, including indications for the strength of the associations. The overview is based on a literature study examining cohort studies tha...
Source: Hearing Research - June 19, 2018 Category: Audiology Authors: Besser J, Stropahl M, Urry E, Launer S Tags: Hear Res Source Type: research

Implications and attitudes of audiologists towards smartphone integration in hearing healthcare.
CONCLUSIONS: The findings suggest that the attitudes of audiologists likely do not represent a barrier regarding smartphone integration in audiologic rehabilitation. PMID: 29945802 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - June 19, 2018 Category: Audiology Authors: Kimball SH, Singh G, John AB, Jenstad LM Tags: Hear Res Source Type: research

The use of ecological momentary assessment in hearing research and future clinical applications.
Abstract To obtain real-world insights into the hearing difficulties of individuals, the field of hearing research has recently started to adopt ecological momentary assessment. Using this approach, study participants describe their experiences in real time, in their own natural environment. This paper describes the use of ecological momentary assessment in hearing research to date. Several studies have shown the approach is feasible and has good construct validity for use with adults with hearing impairment and/or tinnitus. Two recent studies conducted by the authors are described. The first study investigated th...
Source: Hearing Research - June 19, 2018 Category: Audiology Authors: Timmer BHB, Hickson L, Launer S Tags: Hear Res Source Type: research

Frequency specificity of amplitude envelope patterns in noise-vocoded speech.
We examined the frequency specificity of amplitude envelope patterns in 4 frequency bands, which universally appeared through factor analyses applied to power fluctuations of critical-band filtered speech sounds in 8 different languages/dialects [Ueda and Nakajima (2017). Sci. Rep., 7 (42468)]. A series of 3 perceptual experiments with noise-vocoded speech of Japanese sentences was conducted. Nearly perfect (92-94%) mora recognition was achieved, without any extensive training, in a control condition in which 4-band noise-vocoded speech was employed (Experiments 1-3). Blending amplitude envelope patterns of the frequency b...
Source: Hearing Research - June 15, 2018 Category: Audiology Authors: Ueda K, Araki T, Nakajima Y Tags: Hear Res Source Type: research

Effect of sound level on virtual and free-field localization of brief sounds in the anterior median plane.
da EA Abstract The detection of high-frequency spectral notches has been shown to be worse at 70-80 dB sound pressure level (SPL) than at higher levels up to 100 dB SPL. The performance improvement at levels higher than 70-80 dB SPL has been related to an 'ideal observer' comparison of population auditory nerve spike trains to stimuli with and without high-frequency spectral notches. Insofar as vertical localization partly relies on information provided by pinna-based high-frequency spectral notches, we hypothesized that localization would be worse at 70-80 dB SPL than at higher levels. Results from a firs...
Source: Hearing Research - June 14, 2018 Category: Audiology Authors: Marmel F, Marrufo-Pérez MI, Heeren J, Ewert S, Lopez-Poveda EA Tags: Hear Res Source Type: research

Estimation of the ear canal displacement field due to in-ear device insertion using a registration method on a human-like artificial ear.
Abstract Passive and active in-ear devices (IED) occluding the ear canal are commonly used to (i) protect people from high noise levels (earplugs), (ii) assist people suffering from hearing impairment (hearing aids) or (iii) help people in listening from their sound systems (earbuds). However, the usability and/or efficiency of IEDs can be greatly affected by several discomfort components (physical, acoustical and functional). The mechanical pressure exerted by the IED onto the ear canal walls is greatly suspected to affect the aforementioned comfort components. This physical characteristic is closely related to t...
Source: Hearing Research - June 2, 2018 Category: Audiology Authors: Benacchio S, Doutres O, Le Troter A, Varoquaux A, Wagnac E, Callot V, Sgard F Tags: Hear Res Source Type: research

COMT and the neurogenetic architecture of hearing loss induced tinnitus.
Abstract As the COMT polymorphism is especially prominent in the prefrontal cortex and has been associated with auditory gating, we hypothesize that tinnitus patients with this polymorphism have altered activity in the ventromedial prefrontal/anterior cingulate areas that modulates the tinnitus percept. To test this, we recruited a total of 40 tinnitus subjects and 20 healthy controls for an EEG study. A comparison between tinnitus subjects and healthy controls and their frequency of being Val/Val genotype or Met carriers (including Val/Met and Met/Met genotype) shows no significant effect, suggesting that the dis...
Source: Hearing Research - June 1, 2018 Category: Audiology Authors: Vanneste S, Alsalman O, De Ridder D Tags: Hear Res Source Type: research

Brainstem-cortical functional connectivity for speech is differentially challenged by noise and reverberation.
Abstract Everyday speech perception is challenged by external acoustic interferences that hinder verbal communication. Here, we directly compared how different levels of the auditory system (brainstem vs. cortex) code speech and how their neural representations are affected by two acoustic stressors: noise and reverberation. We recorded multichannel (64 ch) brainstem frequency-following responses (FFRs) and cortical event-related potentials (ERPs) simultaneously in normal hearing individuals to speech sounds presented in mild and moderate levels of noise and reverb. We matched signal-to-noise and direct-to-reverbe...
Source: Hearing Research - May 26, 2018 Category: Audiology Authors: Bidelman GM, Davis MK, Pridgen MH Tags: Hear Res Source Type: research

Topography of sound level representation in the FM sweep selective region of the pallid bat auditory cortex.
Abstract Sound level processing is a fundamental function of the auditory system. To determine how the cortex represents sound level, it is important to quantify how changes in level alter the spatiotemporal structure of cortical ensemble activity. This is particularly true for echolocating bats that have control over, and often rapidly adjust, call level to actively change echo level. To understand how cortical activity may change with sound level, here we mapped response rate and latency changes with sound level in the auditory cortex of the pallid bat. The pallid bat uses a 60-30 kHz downward frequency modula...
Source: Hearing Research - May 26, 2018 Category: Audiology Authors: Measor K, Yarrow S, Razak KA Tags: Hear Res Source Type: research

Neural representation of interaural correlation in human auditory brainstem: Comparisons between temporal-fine structure and envelope.
Abstract Central processing of interaural correlation (IAC), which depends on the precise representation of acoustic signals from the two ears, is essential for both localization and recognition of auditory objects. A complex soundwave is initially filtered by the peripheral auditory system into multiple narrowband waves, which are further decomposed into two functionally distinctive components: the quickly-varying temporal-fine structure (TFS) and the slowly-varying envelope. In rats, a narrowband noise can evoke auditory-midbrain frequency-following responses (FFRs) that contain both the TFS component (FFRTFS) a...
Source: Hearing Research - May 23, 2018 Category: Audiology Authors: Wang Q, Lu H, Wu Z, Li L Tags: Hear Res Source Type: research

The effects of aging on auditory cortical function.
Abstract Age-related hearing loss is a prominent deficit, afflicting approximately half of the geriatric population. In many cases, the person may have no deficits in detecting sounds, but nonetheless suffers from a reduced ability to understand speech, particularly in a noisy environment. While rodent models have shown that there are a variety of age-related changes throughout the auditory neuraxis, far fewer studies have investigated the effects at the cortical level. Here I review recent evidence from a non-human primate model of age-related hearing loss at the level of the core (primary auditory cortex, A1) an...
Source: Hearing Research - May 23, 2018 Category: Audiology Authors: Recanzone G Tags: Hear Res Source Type: research

Intracochlear pressure measurements during acoustic shock wave exposure.
Abstract INTRODUCTION: Injuries to the peripheral auditory system are among the most common results of high intensity impulsive acoustic exposure. Prior studies of high intensity sound transmission by the ossicular chain have relied upon measurements in animal models, measurements at more moderate sound levels (i.e. 
Source: Hearing Research - May 19, 2018 Category: Audiology Authors: Greene NT, Alhussaini MA, Easter JR, Argo TF, Walilko T, Tollin DJ Tags: Hear Res Source Type: research

Investigation of the 2f1-f2 and 2f2-f1 distortion product otoacoustic emissions using a computational model of the gerbil ear.
Abstract In this work, a three-dimensional computational model of the gerbil ear is used to investigate the generation of the 2f1-f2 and 2f2-f1 distortion product otoacoustic emissions (DPOAEs). In order to predict both the distortion and reflection sources, cochlear roughness is modeled by introducing random inhomogeneities in the outer hair cell properties. The model was used to simulate the generation of DPOAEs in response to a two-tone stimulus for various primary stimulus levels and frequency ratios. As in published experiments, the 2f1-f2 DPOAEs are mostly dominated by the distortion component while the 2f2-...
Source: Hearing Research - May 19, 2018 Category: Audiology Authors: Wen H, Bowling T, Meaud J Tags: Hear Res Source Type: research

Eardrum and columella displacement in single ossicle ears under quasi-static pressure variations.
Abstract Although most birds encounter large pressure variations during flight, motion of the middle ear components as a result of changing ambient pressure are not well known or described. In the present study, motion of the columella footplate and tympanic membrane (extrastapedius) in domestic chickens (Gallus gallus domesticus) under quasi-static pressure conditions are provided. Micro-CT scans were made of cadaveric heads of chickens under positive (0.25 kPa, 0.5 kPa, 1 kPa, and 1.5 kPa) and negative (-0.25 kPa, -0.5 kPa, -1 kPa, and -1.5 kPa) middle ear pressure. Both extrastape...
Source: Hearing Research - May 19, 2018 Category: Audiology Authors: Claes R, Muyshondt PGG, Van Assche F, Van Hoorebeke L, Aerts P, Dirckx JJJ Tags: Hear Res Source Type: research

A circuit mechanism of time-to-space conversion for perception.
Abstract Sensory information in a temporal sequence is processed as a collective unit by the nervous system. The cellular mechanisms underlying how sequential inputs are incorporated into the brain has emerged as an important subject in neuroscience. Here, we hypothesize that information-bearing (IB) signals can be entrained and amplified by a clock signal, allowing them to efficiently propagate along in a feedforward circuit. IB signals can remain latent on individual dendrites of the receiving neurons until they are read out by an oscillatory clock signal. In such a way, the IB signals pass through the next neur...
Source: Hearing Research - May 17, 2018 Category: Audiology Authors: Yang S, Chung J, Jin SH, Bao S, Yang S Tags: Hear Res Source Type: research

Outlook and future of inner ear therapy.
Abstract Drug delivery to the inner ear is an ideal method to treat a wide variety of otologic conditions. A broad range of potential applications is just beginning to be explored. New approaches combine principles of inner ear pharmacokinetics with emerging technologies of drug delivery including novel delivery systems, drug-device combinations, and new categories of drugs. Strategies include cell-specific targeting, manipulation of gene expression, local activation following systemic delivery, and use of stem cells, viral vectors, and gene editing systems. Translation of these therapies to the clinic remains cha...
Source: Hearing Research - May 17, 2018 Category: Audiology Authors: Devare J, Gubbels S, Raphael Y Tags: Hear Res Source Type: research

Human medial efferent activity elicited by dynamic versus static contralateral noises.
Abstract The medial olivocochlear reflex (MOCR) modifies cochlear amplifier function to improve encoding of signals in static noise, but conflicting results have been reported regarding how the MOCR responds to dynamic, temporally-complex noises. The current study utilized three MOCR elicitors with identical spectral content but different temporal properties: broadband noise, amplitude-modulated noise, and speech envelope-modulated noise. MOCR activity was assessed using contralateral inhibition of transient-evoked otoacoustic emissions in 27 normal-hearing young adults. Elicitors were presented contralaterally at...
Source: Hearing Research - May 16, 2018 Category: Audiology Authors: Mertes IB Tags: Hear Res Source Type: research

Differential fates of tissue macrophages in the cochlea during postnatal development.
Abstract The cochlea contains macrophages. These cells participate in inflammatory responses to cochlear pathogenesis. However, it is not clear how and when these cells populate the cochlea during postnatal development. The current study aims to determine the postnatal development of cochlear macrophages with the focus on macrophage development in the organ of Corti and the basilar membrane. Cochleae were collected from C57BL/6J mice at ages of postnatal day (P) 1 to P21, as well as from mature mice (1-4 months). Macrophages were identified based on their expression of F4/80 and Iba1, as well as their unique morph...
Source: Hearing Research - May 16, 2018 Category: Audiology Authors: Dong Y, Zhang C, Frye M, Yang W, Ding D, Sharma A, Guo W, Hu BH Tags: Hear Res Source Type: research

Diseases and targets for local drug delivery to the inner ear.
PMID: 29778289 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - May 11, 2018 Category: Audiology Authors: Lustig LR Tags: Hear Res Source Type: research

A "voice patch" system in the primate brain for processing vocal information?
A "voice patch" system in the primate brain for processing vocal information? Hear Res. 2018 May 07;: Authors: Belin P, Bodin C, Aglieri V Abstract We review behavioural and neural evidence for the processing of information contained in conspecific vocalizations (CVs) in three primate species: humans, macaques and marmosets. We focus on abilities that are present and ecologically relevant in all three species: the detection and sensitivity to CVs; and the processing of identity cues in CVs. Current evidence, although fragmentary, supports the notion of a "voice patch system" in the...
Source: Hearing Research - May 7, 2018 Category: Audiology Authors: Belin P, Bodin C, Aglieri V Tags: Hear Res Source Type: research

How aging impacts the encoding of binaural cues and the perception of auditory space.
Abstract Over the years, the effect of aging on auditory function has been investigated in animal models and humans in an effort to characterize age-related changes in both perception and physiology. Here, we review how aging may impact neural encoding and processing of binaural and spatial cues in human listeners with a focus on recent work by the authors as well as others. Age-related declines in monaural temporal processing, as estimated from measures of gap detection and temporal fine structure discrimination, have been associated with poorer performance on binaural tasks that require precise temporal processi...
Source: Hearing Research - May 5, 2018 Category: Audiology Authors: Eddins AC, Ozmeral EJ, Eddins DA Tags: Hear Res Source Type: research

Bone morphogenetic protein 4 antagonizes hair cell regeneration in the avian auditory epithelium.
Abstract Permanent hearing loss is often a result of damage to cochlear hair cells, which mammals are unable to regenerate. Non-mammalian vertebrates such as birds replace damaged hair cells and restore hearing function, but mechanisms controlling regeneration are not understood. The secreted protein bone morphogenetic protein 4 (BMP4) regulates inner ear morphogenesis and hair cell development. To investigate mechanisms controlling hair cell regeneration in birds, we examined expression and function of BMP4 in the auditory epithelia (basilar papillae) of chickens of either sex after hair cell destruction by ototo...
Source: Hearing Research - May 2, 2018 Category: Audiology Authors: Lewis RM, Keller JJ, Wan L, Stone JS Tags: Hear Res Source Type: research

Cortical processing of location changes in a "cocktail-party" situation: Spatial oddball effects on electrophysiological correlates of auditory selective attention.
Cortical processing of location changes in a "cocktail-party" situation: Spatial oddball effects on electrophysiological correlates of auditory selective attention. Hear Res. 2018 Apr 27;: Authors: Lewald J, Schlüter MC, Getzmann S Abstract Neural mechanisms of selectively attending to a sound source of interest in a simulated "cocktail-party" situation, composed of multiple competing sources, were investigated using event-related potentials in combination with a spatial oddball design. Subjects either detected rare spatial deviants in a series of standard sounds or passively ...
Source: Hearing Research - April 27, 2018 Category: Audiology Authors: Lewald J, Schlüter MC, Getzmann S Tags: Hear Res Source Type: research

Sound-localization performance of patients with single-sided deafness is not improved when listening with a bone-conduction device.
Abstract An increased number of treatment options has become available for patients with single sided deafness (SSD), who are seeking hearing rehabilitation. For example, bone-conduction devices that employ contralateral routing of sound (CROS), by transmitting acoustic bone vibrations from the deaf side to the cochlea of the hearing ear, are widely used. However, in some countries, cochlear implantation is becoming the standard treatment. The present study investigated whether CROS intervention, by means of a CROS bone-conduction device (C-BCD), affected sound-localization performance of patients with SSD. Severa...
Source: Hearing Research - April 19, 2018 Category: Audiology Authors: Agterberg MJH, Snik AFM, Van de Goor RMG, Hol MKS, Van Opstal AJ Tags: Hear Res Source Type: research

Towards an objective test of chronic tinnitus: Properties of auditory cortical potentials evoked by silent gaps in tinnitus-like sounds.
ert S Abstract A common method designed to identify if an animal hears tinnitus assumes that tinnitus "fills-in" silent gaps in background sound. This phenomenon has not been reliably demonstrated in humans. One test of the gap-filling hypothesis would be to determine if gap-evoked cortical potentials are absent or attenuated when measured within background sound matched to the tinnitus sensation. However the tinnitus sensation is usually of low intensity and of high frequency, and it is unknown if cortical responses can be measured with such "weak" stimulus properties. Therefore the aim of the...
Source: Hearing Research - April 17, 2018 Category: Audiology Authors: Paul BT, Schoenwiesner M, Hébert S Tags: Hear Res Source Type: research

Electric-acoustic forward masking in cochlear implant users with ipsilateral residual hearing.
In conclusion, the forward masking patterns observed for combined electric-acoustic stimulation provide further insights into the temporal mechanisms of the auditory system. For instance, the asymmetry in the amount of threshold elevation, the dependency on EAFD and the time constants for the recovery functions of acoustic and electric masking all indicate that there must be several processes with different latencies (e.g. neural adaptation, depression of spontaneous activity, efferent systems) that are involved in forward masking recovery functions. PMID: 29673567 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 9, 2018 Category: Audiology Authors: Imsiecke M, Krüger B, Büchner A, Lenarz T, Nogueira W Tags: Hear Res Source Type: research

Functions of CaBP1 and CaBP2 in the peripheral auditory system.
Lee A Abstract CaBPs are a family of Ca2+ binding proteins related to calmodulin. Two CaBP family members, CaBP1 and CaBP2, are highly expressed in the cochlea. Here, we investigated the significance of CaBP1 and CaBP2 for hearing in mice lacking expression of these proteins (CaBP1 KO and CaBP2 KO) using auditory brain responses (ABRs) and distortion product otoacoustic emissions (DPOAEs). In CaBP1 KO mice, ABR wave I was larger in amplitude, and shorter in latency and faster in decay, suggestive of enhanced synchrony of auditory nerve fibers. This interpretation was supported by the greater excitability of CaBP1 ...
Source: Hearing Research - April 9, 2018 Category: Audiology Authors: Yang T, Hu N, Pangršič T, Green S, Hansen M, Lee A Tags: Hear Res Source Type: research

A fluorescence-based imaging approach to pharmacokinetic analysis of intracochlear drug delivery.
Abstract Advances in microelectromechanical systems (MEMS) technologies are enhancing the development of intracochlear delivery devices for the treatment of hearing loss with emerging pharmacological therapies. Direct intracochlear delivery addresses the limitations of systemic and intratympanic delivery. However, optimization of delivery parameters for these devices requires pharmacokinetic assessment of the spatiotemporal drug distribution inside the cochlea. Robust methods of measuring drug concentration in the perilymph have been developed, but lack spatial resolution along the tonotopic axis or require comple...
Source: Hearing Research - April 5, 2018 Category: Audiology Authors: Ayoob AM, Peppi M, Tandon V, Langer R, Borenstein JT Tags: Hear Res Source Type: research

Hearing loss in older adults - From epidemiological insights to national initiatives.
Abstract The broader implications of hearing loss for the health and functioning of older adults have begun to be demonstrated in epidemiologic studies. These research findings on the association between hearing loss and poorer health outcomes have formed the foundation for national initiatives on hearing loss and public health. These national initiatives range from the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) clinical trial to the recent passage of the bipartisan Over-The-Counter Hearing Aid Act. Utilizing population health research methodologies to study hearing loss can provide the foundation f...
Source: Hearing Research - April 3, 2018 Category: Audiology Authors: Goman AM, Lin FR Tags: Hear Res Source Type: research

Vestibular and balance function is often impaired in children with profound unilateral sensorineural hearing loss.
CONCLUSIONS: The prevalence of vestibular dysfunction in children with unilateral deafness is high and similar to that of children with bilateral deafness. Vestibular and balance evaluation should be routine and the functional impact of combined vestibulo-cochlear sensory deficits considered. PMID: 29655975 [PubMed - as supplied by publisher] (Source: Hearing Research)
Source: Hearing Research - April 3, 2018 Category: Audiology Authors: Sokolov M, Gordon KA, Polonenko M, Blaser SI, Papsin BC, Cushing SL Tags: Hear Res Source Type: research

Keeping track of sound objects in space: The contribution of early-stage auditory areas.
Abstract The influential dual-stream model of auditory processing stipulates that information pertaining to the meaning and to the position of a given sound object is processed in parallel along two distinct pathways, the ventral and dorsal auditory streams. Functional independence of the two processing pathways is well documented by conscious experience of patients with focal hemispheric lesions. On the other hand there is growing evidence that the meaning and the position of a sound are combined early in the processing pathway, possibly already at the level of early-stage auditory areas. Here, we investigated ho...
Source: Hearing Research - April 1, 2018 Category: Audiology Authors: Da Costa S, Clarke S, Crottaz-Herbette S Tags: Hear Res Source Type: research

Concurrent gradients of ribbon volume and AMPA-receptor patch volume in cochlear afferent synapses on gerbil inner hair cells.
l C Abstract The Mongolian gerbil is a classic animal model for age-related hearing loss. As a prerequisite for studying age-related changes, we characterized cochlear afferent synaptic morphology in young adult gerbils, using immunolabeling and quantitative analysis of confocal microscopic images. Cochlear wholemounts were triple-labeled with a hair-cell marker, a marker of presynaptic ribbons, and a marker of postsynaptic AMPA-type glutamate receptors. Seven cochlear positions covering an equivalent frequency range from 0.5 - 32 kHz were evaluated. The spatial positions of synapses were determined in a coordin...
Source: Hearing Research - April 1, 2018 Category: Audiology Authors: Zhang L, Engler S, Koepcke L, Steenken F, Köppl C Tags: Hear Res Source Type: research

Clinical trials for inner ear drugs: Design and execution challenges.
Abstract The development of therapies for the inner ear presents unique opportunities and challenges. On the one hand, the ear presents an opportunity for localized drug delivery to avoid systemic side effects. However, we do not understand the pathobiology of many common ear disorders clearly enough to develop rational therapeutic solutions. Further, identification of biomarkers beyond conventional audiometry and balance testing to track disease progress and recovery remain elusive. Because of the comparatively low incidence and prevalence of many inner ear disorders, as well as issues with respect to timing of d...
Source: Hearing Research - March 22, 2018 Category: Audiology Authors: Jung DH, Rauch SD Tags: Hear Res Source Type: research

Magnitude and phase of three-dimensional (3D) velocity vector: Application to measurement of cochlear promontory motion during bone conduction sound transmission.
Abstract Recent measurements of vibrational motion to assess sound transmission through ear structures and skull contents have included three-dimensional (3D) behavior. The 3D motion of a point has been described with the three orthogonal components in the 3D space. In this article, a method to represent the 3D velocity with the magnitude and phase of the resultant velocity is introduced. This method was applied to the measurement of cochlear promontory motion as an indication of bone conduction (BC) sound transmission. The promontory motions were measured on the ipsilateral and contralateral sides, and the transc...
Source: Hearing Research - March 21, 2018 Category: Audiology Authors: Dobrev I, Sim JH Tags: Hear Res Source Type: research

Effect of age and hearing loss on auditory stream segregation of speech sounds.
This study compared older HI listeners' performance with that of young and older normal-hearing (NH) listeners in stream segregation tasks involving speech sounds. Listeners were presented with sequences of speech tokens, each consisting of a fricative consonant and a voiced vowel (CV). The CV tokens were concatenated into interleaved sequences that alternated in fundamental frequency (F0) and/or simulated vocal tract length (VTL). Each pair of interleaved sequences was preceded by a "word" consisting of two random tokens. The listeners were asked to indicate whether the word was present in the following interlea...
Source: Hearing Research - March 21, 2018 Category: Audiology Authors: David M, Tausend AN, Strelcyk O, Oxenham AJ Tags: Hear Res Source Type: research

Hidden hearing loss and endbulbs of Held: Evidence for central pathology before detection of ABR threshold increases.
In this study of CBA/CaH mice, we provide evidence for age-related pathology in the endbulb of Held, a large axosomatic ending arising from myelinated auditory nerve fibers. Endbulbs are known to be involved in the processing of temporal cues used for sound localization and speech comprehension. Hearing thresholds as measured by auditory brainstem response (ABR) thresholds remained stable up to one year, whereas suprathreshold amplitudes of early ABR waves decreased by up to 50% in older mice, similar to that reported for age-related cochlear synaptopathy (Sergeyenko et al., 2013). The reduction of ABR response magnit...
Source: Hearing Research - March 20, 2018 Category: Audiology Authors: Muniak MA, Ayeni FE, Ryugo DK Tags: Hear Res Source Type: research

Auditory and audio-vocal responses of single neurons in the monkey ventral premotor cortex.
Abstract Monkey vocalization is a complex behavioral pattern, which is flexibly used in audio-vocal communication. A recently proposed dual neural network model suggests that cognitive control might be involved in this behavior, originating from a frontal cortical network in the prefrontal cortex and mediated via projections from the rostral portion of the ventral premotor cortex (PMvr) and motor cortex to the primary vocal motor network in the brainstem. For the rapid adjustment of vocal output to external acoustic events, strong interconnections between vocal motor and auditory sites are needed, which are presen...
Source: Hearing Research - March 20, 2018 Category: Audiology Authors: Hage SR Tags: Hear Res Source Type: research

Front- and rear-facing horizontal sound localization results in adults with unilateral hearing loss and normal hearing.
Abstract Binaural hearing allows listeners to take advantage of auditory cues that are necessary for sound localization. Patients with asymmetric or unilateral hearing loss receive degraded or absent binaural cues and often demonstrate decreased sound localization in the horizontal plane. Given the importance of sound localization for everyday function, there is a need for clinically feasible methods to evaluate localization, particularly as validation of intervention for patients with unilateral hearing loss. The present study compared sound localization results obtained for front-facing and rear-facing soundfiel...
Source: Hearing Research - March 19, 2018 Category: Audiology Authors: Nelson E, Reeder RM, Holden LK, Firszt JB Tags: Hear Res Source Type: research