Showing papers in "Hearing Research in 2008"

TL;DR: The aims of this paper are to provide a brief history of cochlear implants, present a status report on the current state of implant engineering and the levels of speech understanding enabled by that engineering, describe limitations of current signal processing strategies, and suggest new directions for research.

TL;DR: Findings indicate that speech-evoked FFRs follow both the glottal pitch envelope as well as spectral stimulus components.

TL;DR: Recorded brainstem and cortical evoked responses imply that neural representations of pitch, timing and timbre cues and cortical response timing are shaped in a coordinated manner, and indicate corticofugal modulation of subcortical afferent circuitry.

TL;DR: It is found that both age and stimulus rate produced profound changes in CAEP morphology, and the presence of N2 in adolescents indicates that auditory cortical maturation persists into teen years.

TL;DR: Preliminary results of additional neurophysiological and human psychophysical studies are presented that demonstrate the success of current steering strategies in stimulating auditory nerve regions lying between physical CI electrodes, as well as current focusing strategies that excite regions narrower than those stimulated using monopolar configurations.

TL;DR: Fundamental frequency (F0) processing by cochlear implant (CI) listeners was measured using a psychophysical task and a speech intonation recognition task and significant correlations were observed between the CI listeners' sensitivity to modulation frequency in the psychophysicaltask and their performance in intonations recognition.

TL;DR: In this paper, the authors applied 0.1-6% DMSO for 24h to cochlear organotypic cultures from postnatal day 3 rats and examined its cytotoxic effects.

TL;DR: It is suggested that cochlear implantation alone may not fully meet the needs of many patients, and that additional auditory rehabilitation may be needed to maximize the benefits of the implant device.

TL;DR: This chapter will concentrate on research done with the Iowa/Nucleus 10 mm Hybrid device, but it will also attempt to summarize strategies and results from other groups around the world who use slightly different approaches.

TL;DR: The correlation between surviving spiral ganglion cells, following acute and chronic deafness induced by neomycin application into the middle ear, and neural stimulation using optical radiation and electrical current is explored.

TL;DR: Chronic ES can prevent the rapid loss of SGNs that occurs after the withdrawal of exogenous NTs, suggesting that chronic ES can maintain SGN survival long after cessation of NT delivery.

TL;DR: The adult-like performance of many younger children at times during their testing or training, together with the high response variability of immature performers, suggested that most elevated FD thresholds in children are due to inattention.

TL;DR: Responses of the whole-nerve response are reviewed, the extent to which they provide information about underlying auditory nerve fiber activity, and limitations to their interpretation to improve understanding of how the human auditory system responds to electrical stimulation.

TL;DR: Results suggest that the presence of differentiated supporting cells in the organ of Corti is necessary for transdifferentiation to occur, and forced expression of Atoh1 in the differentiated supporting cell population can induce trans Differentiation leading to hair cell regeneration.

TL;DR: Most current auditory prostheses seem to deliver adequate temporal-envelope information, but the number of effective channels is suboptimal, particularly for speech recognition in noise, lexical tone recognition, and music perception.

TL;DR: The slow high-frequency hearing loss combined with a modest reduction of ganglion cell density and an unchanged endocochlear potential suggest sensorineural presbycusis in aged male CBA/J mice.

TL;DR: This study evaluates the spread of activity evoked by cochlear implant channels by monitoring activity at 16 sites along the tonotopic axis of the guinea pig inferior colliculus by measuring "Spatial tuning curves" (STCs) measured as an estimate of activation spread within the cochlea and the ascending auditory pathways.

TL;DR: Recent progress in understanding of noise injury through mouse models is reviewed, including new evidence for a phagocytic function of supporting cells in removing damaged outer hair cells, and the potential role in NIHL of the cochlear lateral wall is updated in light of newly discovered functions of gap junctions.

TL;DR: Results showed significant interaction between spectral resolution (number of channels) and spread of excitation, which is partly consistent with behavioral data obtained with cochlear implant studies in that CI users tend to do as well or better with monopolar stimulation than with bipolar stimulation.

TL;DR: The findings do validate the concept of intranuclear stimulation and suggest how such prostheses might be improved by modifying the microstimulating array and also by optimizing the sound processing strategies.

TL;DR: In cochlear implant patients with functional hearing in the non-implanted ear, electrical stimulation produced a frequency-place function that on average resembles Greenwood's function, which differs from previously derived data.

TL;DR: Robust AEPs, with waveforms demonstrably different from those of the core or lateral belt, were localized to the posterolateral surface of the STG and conform to previously described field PLST.

TL;DR: The size of mitochondria, perikaryal area and cell circularity of the remaining untreated SGCs were decreased and the number of layers of the myelin sheath was reduced and in the basal part of the cochlea BDNF treatment rescued S GCs from degeneration.

TL;DR: Results indicate that the changes in the anatomy of the auditory nerve induced by the combination of Ad.BDNF inoculation and the electrical stimulation used for testing improved functional measures of CI performance.

TL;DR: Localized cell and drug delivery to the cochlea and central auditory pathway can improve the safety and performance of implanted auditory prosthetic devices and the gradual degeneration of the auditory system following deafness.

TL;DR: Spatial tuning properties of units in the cat's anterior auditory field were assessed and spike-pattern-recognition analyses indicated that units in AAF transmitted less spatial information than did units in PAF-an observation consistent with recent evidence that PAF is necessary for sound-localization behavior, whereas AAF is not.

TL;DR: It is found that optical aberrations present in the decalcified cochlea can be greatly reduced by dehydration through graded ethanols followed by clearing with a mixture of five parts methyl salicylate and three parts benzyl benzoate (MSBB), which promises to be particularly useful for three-dimensional characterization of anatomy, innervation and expression of genes or proteins in the many new animal models of hearing and balance generated by genetic manipulation.

TL;DR: The findings suggest that SS may preferentially target GABA neurons and consequently interrupt a normal level of GABAergic synaptic transmissions maintained by the serotonergic system in SS-induced tinnitus.

TL;DR: Only hair cell and marginal cell uptake of GTTR is competitively inhibited by gentamicin, suggesting that a regulatable barrier for gentamic in entry into endolymph exists at the interface between marginal cells, the intra-strial space and intermediate cells.

TL;DR: Two important findings are that anodic currents are more effective than cathodic stimulation for human CI patients and that the thresholds decrease with increases in IPG over a much longer time course (more than 3 ms) than for animals.