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Auditory Sensitivity (auditory + sensitivity)
Selected AbstractsOn the relationship between dynamic visual and auditory processing and literacy skills; results from a large primary-school studyDYSLEXIA, Issue 4 2002Joel B. Talcott Abstract Three hundred and fifty randomly selected primary school children completed a psychometric and psychophysical test battery to ascertain relationships between reading ability and sensitivity to dynamic visual and auditory stimuli. The first analysis examined whether sensitivity to visual coherent motion and auditory frequency resolution differed between groups of children with different literacy and cognitive skills. For both tasks, a main effect of literacy group was found in the absence of a main effect for intelligence or an interaction between these factors. To assess the potential confounding effects of attention, a second analysis of the frequency discrimination data was conducted with performance on catch trials entered as a covariate. Significant effects for both the covariate and literacy skill was found, but again there was no main effect of intelligence, nor was there an interaction between intelligence and literacy skill. Regression analyses were conducted to determine the magnitude of the relationship between sensory and literacy skills in the entire sample. Both visual motion sensitivity and auditory sensitivity to frequency differences were robust predictors of children's literacy skills and their orthographic and phonological skills. Copyright © 2002 John Wiley & Sons, Ltd. [source] The ultrastructural distribution of prestin in outer hair cells: a post-embedding immunogold investigation of low-frequency and high-frequency regions of the rat cochleaEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2010Shanthini Mahendrasingam Abstract Outer hair cells (OHCs) of the mammalian cochlea besides being sensory receptors also generate force to amplify sound-induced displacements of the basilar membrane thus enhancing auditory sensitivity and frequency selectivity. This force generation is attributable to the voltage-dependent contractility of the OHCs underpinned by the motile protein, prestin. Prestin is located in the basolateral wall of OHCs and is thought to alter its conformation in response to changes in membrane potential. The precise ultrastructural distribution of prestin was determined using post-embedding immunogold labelling and the density of the labelling was compared in low-frequency and high-frequency regions of the cochlea. The labelling was confined to the basolateral plasma membrane in hearing rats but declined towards the base of the cells below the nucleus. In pre-hearing animals, prestin labelling was lower in the membrane and also occurred in the cytoplasm, presumably reflecting its production during development. The densities of labelling in low-frequency and high-frequency regions of the cochlea were similar. Non-linear capacitance, thought to reflect charge movements during conformational changes in prestin, was measured in OHCs in isolated cochlear coils of hearing animals. The OHC non-linear capacitance in the same regions assayed in the immunolabelling was also similar in both the apex and base, with charge densities of 10 000/,m2 expressed relative to the lateral membrane area. The results suggest that prestin density, and by implication force production, is similar in low-frequency and high-frequency OHCs. [source] Whining as mother-directed speechINFANT AND CHILD DEVELOPMENT, Issue 5 2005Rosemarie I. Sokol Abstract Although little studied, whining is a vocal pattern that is both familiar and irritating to parents of preschool- and early school-age children. The current study employed multidimensional scaling to identify the crucial acoustic characteristics of whining speech by analysing participants' perceptions of its similarity to other types of speech (question, neutral speech, angry statement, demand, and boasting). We discovered not only that participants find whining speech more annoying than other forms of speech, but that it shares the salient acoustic characteristics found in motherese, namely increased pitch, slowed production, and exaggerated pitch contours. We think that this relationship is not random but may reflect the fact that the two forms of vocalization are the result of a similar accommodation to a universal human auditory sensitivity to the prosody of both forms of speech. Copyright © 2005 John Wiley & Sons, Ltd. [source] Effects of musical expertise on the early right anterior negativity: An event-related brain potential studyPSYCHOPHYSIOLOGY, Issue 5 2002Stefan Koelsch Event-related brain potentials in response to harmonically inappropriate chords were compared for musical experts and novices. Similar to previous studies, these chords elicited an early right anterior negativity (ERAN). The amplitude of the ERAN was clearly larger for musical experts than for novices, presumably because experts had more specific musical expectancies than novices. Chords with a physically deviant timbre elicited a mismatch negativity that did not differentiate the groups, indicating that the larger ERAN in experts was not due to a general enhanced auditory sensitivity. The ERAN reflects fast and automatic neural mechanisms that process complex musical (music-syntactic) irregularities, and the present results indicate that these mechanisms can be modulated by expertise. [source] Auditory Brainstem Implantation in Patients with Neurofibromatosis Type 2,THE LARYNGOSCOPE, Issue 12 2004Seth J. Kanowitz MD Abstract Objectives: Multichannel auditory brainstem implants (ABI) are currently indicated for patients with neurofibromatosis type II (NF2) and schwannomas involving the internal auditory canal (IAC) or cerebellopontine angle (CPA), regardless of hearing loss (HL). The implant is usually placed in the lateral recess of the fourth ventricle at the time of tumor resection to stimulate the cochlear nucleus. This study aims to review the surgical and audiologic outcomes in 18 patients implanted by our Skull Base Surgery Team from 1994 through 2003. Study Design: A retrospective chart review of 18 patients with ABIs. Methods: We evaluated demographic data including age at implantation, number of tumor resections before implantation, tumor size, surgical approach, and postoperative surgical complications. The ABI auditory results at 1 year were then evaluated for number of functioning electrodes and channels, hours per day of use, nonauditory side effect profile and hearing results. Audiologic data including Monosyllable, Spondee, Trochee test (MTS) Word and Stress scores, Northwestern University Children's Perception of Speech (NU-CHIPS), and auditory sensitivity are reported. Results: No surgical complications caused by ABI implantation were revealed. A probe for lateral recess and cochlear nucleus localization was helpful in several patients. A range of auditory performance is reported, and two patients had no auditory perceptions. Electrode paddle migration occurred in two patients. Patient education and encouragement is very important to obtain maximum benefit. Conclusions: ABIs are safe, do not increase surgical morbidity, and allow most patients to experience improved communication as well as access to environmental sounds. Nonauditory side effects can be minimized by selecting proper stimulation patterns. The ABI continues to be an emerging field for hearing rehabilitation in patients who are deafened by NF2. [source] Acoustic communication in crocodilians: from behaviour to brainBIOLOGICAL REVIEWS, Issue 3 2009A. L. Vergne ABSTRACT Crocodilians and birds are the modern representatives of Phylum Archosauria. Although there have been recent advances in our understanding of the phylogeny and ecology of ancient archosaurs like dinosaurs, it still remains a challenge to obtain reliable information about their behaviour. The comparative study of birds and crocodiles represents one approach to this interesting problem. One of their shared behavioural features is the use of acoustic communication, especially in the context of parental care. Although considerable data are available for birds, information concerning crocodilians is limited. The aim of this review is to summarize current knowledge about acoustic communication in crocodilians, from sound production to hearing processes, and to stimulate research in this field. Juvenile crocodilians utter a variety of communication sounds that can be classified into various functional categories: (1) "hatching calls", solicit the parents at hatching and fine-tune hatching synchrony among siblings; (2) "contact calls", thought to maintain cohesion among juveniles; (3) "distress calls", induce parental protection; and (4) "threat and disturbance calls", which perhaps function in defence. Adult calls can likewise be classified as follows: (1) "bellows", emitted by both sexes and believed to function during courtship and territorial defence; (2) "maternal growls", might maintain cohesion among offspring; and (3) "hisses", may function in defence. However, further experiments are needed to identify the role of each call more accurately as well as systematic studies concerning the acoustic structure of vocalizations. The mechanism of sound production and its control are also poorly understood. No specialized vocal apparatus has been described in detail and the motor neural circuitry remains to be elucidated. The hearing capabilities of crocodilians appear to be adapted to sound detection in both air and water. The ear functional anatomy and the auditory sensitivity of these reptiles are similar in many respects to those of birds. The crocodilian nervous system likewise shares many features with that of birds, especially regarding the neuroanatomy of the auditory pathways. However, the functional anatomy of the telencephalic auditory areas is less well understood in crocodilians compared to birds. [source] | |||||||||||||