Showing papers in "Hearing Research in 1987"

TL;DR: Examination of pure-tone acoustic damage in the chick cochlea revealed a significant amount of hair cell recovery over a 10 day period following the exposure, which included both a regeneration of stereociliary bundles to replace those that were lost and a reshuffle of the mosaic pattern of the hair cell surfaces that survived.

TL;DR: The auditory filter may be considered as a weighting function representing frequency selectivity at a particular centre frequency using the power-spectrum model of masking, and the relationship of the auditory filter shape and the excitation pattern are described.

TL;DR: It is suggested that in the control of tinnitus the same interplay exists between large inner-hair-cell fibers, and small outer- hair- cell fibers, provided they are deafferented, that was demonstrated to exist between large and small deAfferented fibers of the somato-sensory system in the Control of pain.

TL;DR: Using suppression, interfering tones, and temporary threshold shift procedures, the work reported here was designed to establish more definitively the precise contributions of the basilar-membrane regions involved in generating acoustic DPs in rabbits.

TL;DR: Spatial maps of electrical excitation were constructed by comparing electrical threshold with acoustic CF for large populations of auditory nerve fibers in cats, finding minima were sharper and deeper and spread of excitation occurred at intensities above the minimum threshold.

TL;DR: Two cochleas with permanent, noise-induced threshold shifts of 40 to 60 dB were analyzed in detail, first at the light- microscopic level, and subsequently with transmission electron microscopy of serial sections, suggesting that most of the structures which appear normal in a careful light-microscopic analysis are also normal at the ultrastructural level.

TL;DR: It is shown that the cell potential is more positive than the EP+, and that the ion pump is conventional Na,K-ATPase, probably in the basolateral membrane of the marginal cells of the stria vascularis.

TL;DR: Threshold, latency, and amplitude of the auditory brainstem response (ABR) were obtained in young and aging C57BL/6J mice and CBA/J mice, which undergo severe progressive age-related sensorineural hearing loss and can help to clarify some inconsistencies in the human literature on aging and the ABR.

TL;DR: A number of the general features of acoustic-DP generation in the rabbit are investigated so that, in later experiments, the contributions of specific basilar-membrane regions involved in generating these DPs can be identified using techniques designed to manipulate their normal properties.

TL;DR: MOC stimulation and fourth-ventricle OCB stimulation both produced qualitatively similar results bilaterally in that auditory-nerve compound action potential (N1) and endocochlear potential were reduced, and cochlear microphonic (CM) was increased.

TL;DR: This study compares human brain stem auditory centers with those of the cat in terms of their topography and cytoarchitecture and describes differences in configuration of human auditory centers, such as mediolateral elongation of the cochlear nuclei and rostral prolongation ofThe superior olivary complex.

TL;DR: The oto-acoustic emissions generated in response to two-tone stimulation have been studied in the ear canal sound pressure of three species of rodent: rat, guinea pig and Mongolian gerbil and can be distinguished from that of the other two species in a number of details.

TL;DR: Responses to an unprocessed synthetic vowel stimulus were dominated by pitch period, first formant, and 'spurious' components.

TL;DR: The existence of a travelling wave mode, propagating from base to apex, was established for papillae in apparently good physiological condition, and tonotopy of BM CF was still evident, although the correlation with distance was less.

TL;DR: Results are consistent with the hypothesis that far-field-recorded FFR does reflect neural activity germane to the processing of low pitch and that such pitch-relevant activity is based on the temporal discharge patterns of neurons in the upper auditory brainstem pathway.

TL;DR: Although neurons in the inferior colliculus of the anesthetized rat are selectively sensitive to the modulation frequency of dynamic stimuli, the response characteristics are not invariant, but instead are closely dependent on the conditions under which the modulation is presented.

TL;DR: It is demonstrated that there is a small but significant decline in cochlear blood flow with high intensity sound exposure, however, the relationship between this change in blood flow and the development of co chlear damage is unclear.

TL;DR: The results of this study indicate the tectorial membrane contains at least three different collagen types and, in addition to these collagenous proteins, several non-collagenous, glycosylated, disulphide bonded, high molecular weight polypeptides that may account for as much as 50% of the total tECTorial membrane protein.

TL;DR: The relationship between transducer conductance and stereocilia displacement in IHCs and OHCs is non-linear and largely accounts for the depolarizing asymmetry of the voltage response.

TL;DR: An unmyelinated terminal length of 10.0 micron was found to most accurately describe the experimental neural strength-duration curves obtained from aminoglycoside-deafened squirrel monkeys, which affects all conduction pathways, across the membrane and through the fiber.

TL;DR: Changes in the auditory nerve action potential, evoked responses from the inferior colliculus and auditory cortex and the enhancement of the AC-ER which resembles recruitment and which may be a sign of hypersensitivity of the animal to auditory stimuli was present when the animals exposed to noise were awake.

TL;DR: Findings indicate that the tectorial membrane is regenerated in parallel with the hair cells during recovery from acoustic trauma but the full extent of this recovery and its effect on cochlear function are not yet clear.

TL;DR: Data on the size, location, and orientation of humanbrain stem auditory nuclei are discussed here from the point of view of the potential role of these structures in generation of the brain stem auditory evoked response.

TL;DR: Most viable dominant spotting (Wv/Wv) mutant mice, which show cochleo-saccular degeneration, were found to have an endocochlear potential around zero together with a structurally abnormal stria vascularis, confirming that the pathological processes in this mutant are fundamentally different from the pathology in animals with neuroepithelial abnormalities reported previously.

TL;DR: Results suggest that developmental changes in the location and extent of hair cell damage depend on the effective stimulus intensity reaching the cochlea, rather than on alterations in the frequency coding of the hair cells.

TL;DR: Electromyographic activity was used to monitor contractions of the stapedius muscle evoked by both ipsilateral and contralateral sound in ketamine-anesthetized or decerebrate cats, finding that the uncrossed reflex evokes considerably more stapedia EMG than does the crossed reflex, which produces correspondingly greater changes in middle-ear sound transmission.

TL;DR: Outdoor hair cells isolated from guinea pig, chinchilla, rat, mouse, and gerbil showed typical early signs of degeneration were increased Brownian motion and granulation in the cytoplasm, upward movement of the nucleus, or distortion of cell shape.

TL;DR: The cochleae of anaesthetized guinea pigs were prepared for scanning electron microscopy, immediately after exposure to an intense tone, and the results suggest that tip links between stereocilia are preserved as long as the other links between the stereOCilia and the cytoskeleton of the stereocilium remain intact.

TL;DR: No systematic changes were detected in these synaptic responses as a function of age but this may have been because the variability in the shape and timing of synaptic responses was large even in mature tissue.

TL;DR: In the group of 50 cochlea from 28 men aged 38-73 years a great variability in the length of the cochlear duct was found ranging from 28.0 to 40.1 mm, which indicates that long coChleae have more sensory cells in a given frequency region.