Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “auditory”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources
PubMed2002

Auditory brainstem evoked potentials in early-treated congenital hypothyroidism.

To evaluate the effect of early treatment of congenital hypothyroidism on central nervous system development, auditory brainstem evoked potentials were determined in 32 patients with hyperthyrotropinemia diagnosed during neonatal screening. The patients included 27 with congenital hypothyroidism and 5 with transient hypothyroidism. Abnormal auditory brainstem evoked potential tracings were found in 8 patients (congenital hypothyroidism in 7 and transient hypothyroidism in 1). Four of these patients had increased peripheral conduction time (wave I prolongation), and the other 4 had increased central conduction time (wave III or V prolongation). The patients with abnormal auditory brainstem evoked potentials did not show increased initial manifestations, yet 6 of them had lower initial thyroxine levels. Specific auditory brainstem evoked potential abnormalities were found in 25% of early-treated patients with congenital hypothyroidism. The possible causal relationship between deviant auditory brainstem evoked potential patterns and later neurodevelopment demands further clarification. This study suggests the usefulness of auditory brainstem evoked potential assessment to provide information about electrophysiologic deviation of the auditory pathway in patients with early-treated congenital hypothyroidism.

Child, Preschool↗
PubMed1990

Auditory brain stem response and electrically elicited blink reflex in handicapped children.

The auditory brain stem response and the blink reflex were studied in 35 handicapped children in order to evaluate brain stem function. The auditory brain stem response and the blink reflex were abnormal in 20 and 16 cases, respectively. Of these, 14 had both auditory brain stem response and blink reflex abnormalities. The prevalence of auditory brain stem response and blink reflex abnormalities was high in severely handicapped children with difficulty in chewing or swallowing. The blink reflex was abnormal in four of 32 sides with a normal auditory brain stem response and 15 of 23 sides with an abnormal auditory brain stem response threshold, which reflects hearing loss or brain stem dysfunction. We conclude that the combined application of these two noninvasive tests is useful not only to delineate the extent of brain stem lesions but also to determine whether or not patients with an abnormal auditory brain stem response threshold have brain stem dysfunction.

Acoustic Stimulation↗
PubMed1987

Avulsion rupture of the internal auditory artery during operations in the cerebellopontine angle: a study in monkeys.

The effect of manipulations in the cerebellopontine (CP) angle on the cochlear nerve was studied in 12 rhesus monkeys to elucidate how surgical procedures in the CP angle may affect the peripheral auditory system. Brain stem auditory evoked potentials and compound action potentials from the cochlear nerve were recorded throughout the experiments and were studied to determine the level of injury to the cochlear nerve. After the manipulations, the animals were perfused with fixatives and their temporal bones were removed and examined histologically. The monkeys showed electrophysiological changes similar to those observed in humans as a result of surgical manipulations in the CP angle. Avulsions of the internal auditory artery and cochlear nerve fibers at the area cribrosa were the most common histological findings. The auditory evoked potentials were suddenly and irreversibly lost during the manipulations in 3 monkeys, and hemorrhagic foci were identified histologically in these animals at the fundus of the internal auditory canal (the area cribrosa). No morphological changes at locations other than the area cribrosa were identified in these 3 monkeys. The results of this study indicate that injury to the internal auditory artery at the area cribrosa may play an important role in the abrupt loss of hearing experienced by some patients while they are undergoing operations in the CP angle. This study also led to speculation regarding the possible existence of collateral circulation to the cochlea as a factor in injury to the internal auditory artery during acoustic neurinoma operations.

Animals↗
PubMed1989

Principles of auditory information-processing derived from neuroethology.

For auditory imaging, a bat emits orientation sounds (pulses) and listens to echoes. The parameters characterizing a pulse-echo pair each convey particular types of biosonar information. For example, a Doppler shift (a difference in frequency between an emitted pulse and its echo) carries velocity information. For a 61-kHz sound, a 1.0-kHz Doppler shift corresponds to 2.8 ms-1 velocity. The delay of the echo from the pulse conveys distance (range) information. A 1.0-ms echo delay corresponds to a target distance of 17 cm. The auditory system of the mustached bat, Pteronotus parnelli, from Central America solves the computational problems in analyzing these parameters by creating maps in the cerebral cortex. The pulse of the mustached bat is complex. It consists of four harmonics, each of which contains a long constant-frequency (CF) component and a short frequency-modulated (FM) component. Therefore, there are eight components in the emitted pulse (CF1-4 and FM1-4). The CF signal is particularly suited for target velocity measurement, whereas the FM signal is suited for target distance measurement. Since the eight components differ from each other in frequency, they are analyzed in parallel at different regions of the basilar membrane in the inner ear. Then, they are separately coded by primary auditory neurons and are sent up to the auditory cortex through several auditory nuclei. During the ascent of the signals through these auditory nuclei, neurons responding to the FM components process range information, while other neurons responding to the CF components process velocity information. A comparison of the data obtained from the mustached bat with those obtained from other species illustrates both the specialized neural mechanisms specific to the bat's auditory system, and the general neural mechanisms which are probably shared with many different types of animals.

Afferent Pathways↗
PubMed2004

Multiple time scales of adaptation in auditory cortex neurons.

Neurons in primary auditory cortex (A1) of cats show strong stimulus-specific adaptation (SSA). In probabilistic settings, in which one stimulus is common and another is rare, responses to common sounds adapt more strongly than responses to rare sounds. This SSA could be a correlate of auditory sensory memory at the level of single A1 neurons. Here we studied adaptation in A1 neurons, using three different probabilistic designs. We showed that SSA has several time scales concurrently, spanning many orders of magnitude, from hundreds of milliseconds to tens of seconds. Similar time scales are known for the auditory memory span of humans, as measured both psychophysically and using evoked potentials. A simple model, with linear dependence on both short-term and long-term stimulus history, provided a good fit to A1 responses. Auditory thalamus neurons did not show SSA, and their responses were poorly fitted by the same model. In addition, SSA increased the proportion of failures in the responses of A1 neurons to the adapting stimulus. Finally, SSA caused a bias in the neuronal responses to unbiased stimuli, enhancing the responses to eccentric stimuli. Therefore, we propose that a major function of SSA in A1 neurons is to encode auditory sensory memory on multiple time scales. This SSA might play a role in stream segregation and in binding of auditory objects over many time scales, a property that is crucial for processing of natural auditory scenes in cats and of speech and music in humans.

Acoustic Stimulation↗
PubMedDate not supplied

[Auditory evoked potentials in individuals over 50 years].

BACKGROUND: auditory evoked potentials. AIM: to describe the results of brainstem auditory evoked potentials (PEATE), middle latency auditory evoked potentials (PEAML) and cognitive potential (P300) in individuals over 50 years. METHOD: this study was developed at the Speech and Hearing Investigation Laboratory in Auditory Evoked Potentials of the Speech-Language and Hearing Course of the Department of Physiotherapy, Speech-language and Hearing Sciences and Occupational Therapy of FMUSP. Twenty four subjects (45 ears) were evaluated through PEATE and P300, and only 18 of these subjects (36 ears) were evaluated through PEAML. All subjects had ages between 51 and 74 years and were divided in three groups: GI (50-59 years), GII (60-69 years) and GIII (70-79 years). All subjects presented either normal hearing or neurossensorial hearing loss of a moderate-severe level in the PEATE, and of a moderate level in the PEAML and in the P300. The frequency range evaluated in the PEATE and in the PEAML varied from 3000 to 6000Hz, while in the P300 it varied from 1000 to 1500Hz. For the statistical analyses of the data, the Kruskal-Wallis test, the Mann-Whitney test and the two proportion equality test were used. RESULTS: significant statistical differences were simultaneously observed between the groups for the interpeak I-V in the PEATE and for the Na wave latency in the PEAML - in the PEATE the difference was caused by GIII and in the PEAML it was caused by GI. A statistically significant difference between the groups was observed for the latency of the P300 component. Considerable alterations were also found regarding the quality of the responses of the auditory evoked potentials, indicating a strong correlation between the deterioration of the responses and the increase in age. CONCLUSION: the aging process of the auditory system progressively affects the auditory pathways throughout the brainstem and temporal lobe.

Age Factors↗
PubMed2004

A basic study on universal design of auditory signals in automobiles.

In this paper, the impression of various kinds of auditory signals currently used in automobiles and a comprehensive evaluation were measured by a semantic differential method. The desirable acoustic characteristic was examined for each type of auditory signal. Sharp sounds with dominant high-frequency components were not suitable for auditory signals in automobiles. This trend is expedient for the aged whose auditory sensitivity in the high frequency region is lower. When intermittent sounds were used, a longer OFF time was suitable. Generally, "dull (not sharp)" and "calm" sounds were appropriate for auditory signals. Furthermore, the comparison between the frequency spectrum of interior noise in automobiles and that of suitable sounds for various auditory signals indicates that the suitable sounds are not easily masked. The suitable auditory signals for various purposes is a good solution from the viewpoint of universal design.

Adult↗
PubMed1976

Age, sex, and delay time as factors affecting reaction to delayed auditory feedback.

Five groups of 10 males and 10 females each, aged 5, 7, 9, 11, and 13 yr., recited a nursery rhyme under normal delay and 113, 226, 306-m 403-, and 520-msec, delayed auditory-feedback conditions. Speaking rate and disfluency count changes from normal delay to each delayed auditory feedback condition were calculated as indicators of reaction to delayed auditory feedback. Analyses of variance and post hoc comparisons indicated that 5-yr.-olds reacted with greater change in rate at 520-msec. delayed auditory feedback than did older subjects. Five- and 7-yr.-olds were more disfluent at 413-and 520-msec. delayed auditory feedback than were older subjects. Sex differences were found in the 7-, 11-, and 13-yr.-old groups, using speaking rate as a measure of delayed auditory-feedback reaction. No significant sex differences were noted when disfluencies were used as indicators of delayed auditory-feedback reaction.

Adolescent↗
PubMed2001

A two-stage model for visual-auditory interaction in saccadic latencies.

In two experiments, saccadic response time (SRT) for eye movements toward visual target stimuli at different horizontal positions was measured under simultaneous or near-simultaneous presentation of an auditory nontarget (distractor). The horizontal position of the auditory signal was varied, using a virtual auditory environment setup. Mean SRT to a visual target increased with distance to the auditory nontarget and with delay of the onset of the auditory signal relative to the onset of the visual stimulus. A stochastic model is presented that distinguishes a peripheral processing stage with separate parallel activation by visual and auditory information from a central processing stage at which intersensory integration takes place. Two model versions differing with respect to the role of the auditory distractors are tested against the SRT data.

Adult↗
PubMed2004

Reproduction of auditory and visual standards in monochannel cochlear implant users.

The temporal reproduction of standard durations ranging from 1 to 9 seconds was investigated in monochannel cochlear implant (CI) users and in normally hearing subjects for the auditory and visual modality. The results showed that the pattern of performance in patients depended on their level of auditory comprehension. Results for CI users, who displayed relatively good auditory comprehension, did not differ from that of normally hearing subjects for both modalities. Patients with poor auditory comprehension significantly overestimated shorter auditory standards (1, 1.5 and 2.5 s), compared to both patients with good comprehension and controls. For the visual modality the between-group comparisons were not significant. These deficits in the reproduction of auditory standards were explained in accordance with both the attentional-gate model and the role of working memory in prospective time judgment. The impairments described above can influence the functioning of the temporal integration mechanism that is crucial for auditory speech comprehension on the level of words and phrases. We postulate that the deficits in time reproduction of short standards may be one of the possible reasons for poor speech understanding in monochannel CI users.

Acoustic Stimulation↗
PubMed1999

Early visual experience shapes the representation of auditory space in the forebrain gaze fields of the barn owl.

Auditory spatial information is processed in parallel forebrain and midbrain pathways. Sensory experience early in life has been shown to exert a powerful influence on the representation of auditory space in the midbrain space-processing pathway. The goal of this study was to determine whether early experience also shapes the representation of auditory space in the forebrain. Owls were raised wearing prismatic spectacles that shifted the visual field in the horizontal plane. This manipulation altered the relationship between interaural time differences (ITDs), the principal cue used for azimuthal localization, and locations of auditory stimuli in the visual field. Extracellular recordings were used to characterize ITD tuning in the auditory archistriatum (AAr), a subdivision of the forebrain gaze fields, in normal and prism-reared owls. Prism rearing altered the representation of ITD in the AAr. In prism-reared owls, unit tuning for ITD was shifted in the adaptive direction, according to the direction of the optical displacement imposed by the spectacles. Changes in ITD tuning involved the acquisition of unit responses to adaptive ITD values and, to a lesser extent, the elimination of responses to nonadaptive (previously normal) ITD values. Shifts in ITD tuning in the AAr were similar to shifts in ITD tuning observed in the optic tectum of the same owls. This experience-based adjustment of binaural tuning in the AAr helps to maintain mutual registry between the forebrain and midbrain representations of auditory space and may help to ensure consistent behavioral responses to auditory stimuli.

Adaptation, Physiological↗
PubMed1999

Individual differences in auditory and visual attention among fetal alcohol-affected adults.

BACKGROUND: Deficits in attention are commonly identified among patients who have been prenatally exposed to alcohol, and they often affect the ability of the patients to function appropriately in society. METHODS: Eleven adult patients with fetal alcohol syndrome (FAS) or fetal alcohol effects (FAE) were compared with nine adult subjects with no history of prenatal alcohol exposure, using four tests of visually and auditorially mediated attention. RESULTS: In relation to the comparison group, patients with FAS/FAE exhibited substantial deficits in both auditory and visual attention; the auditory deficits were greater. We observed two predominant patterns of deficits among patients with FAS/FAE, one involving both auditory and visual attention problems and the other involving less severe auditory problems and even fewer visual problems. Most subjects with FAS or FAE had some manifestations of attention problems in at least one of the tests of attention used in this study. We present a new graphical representation of individual auditory Continuous Performance Test data across a 6-min period, which, compared with conventional scores, more clearly reveals the markedly disrupted and variable attention patterns displayed by some individuals with FAS or FAE. CONCLUSIONS: These findings suggest that detailed analysis of the pattern of individual performance for each subject is an important aspect of Continuous Performance Test assessment. Our findings further suggest that intellectual performance (intelligence quotient score) alone is not sufficient to account for the patterns of disrupted attention for individuals with FAS/FAE. Assessment of individuals with FAS or FAE should include measurement of attentional functioning in both the visual and auditory modalities.

Adult↗
PubMed2001

Auditory space-time receptive field dynamics revealed by spherical white-noise analysis.

Numerous studies have investigated the spatial sensitivity of cat auditory cortical neurons, but possible dynamic properties of the spatial receptive fields have been largely ignored. Given the considerable amount of evidence that implicates the primary auditory field in the neural pathways responsible for the perception of sound source location, a logical extension to earlier observations of spectrotemporal receptive fields, which characterize the dynamics of frequency tuning, is a description that uses sound source direction, rather than sound frequency, to examine the evolution of spatial tuning over time. The object of this study was to describe auditory space-time receptive field dynamics using a new method based on cross-correlational techniques and white-noise analysis in spherical auditory space. This resulted in a characterization of auditory receptive fields in two spherical dimensions of space (azimuth and elevation) plus a third dimension of time. Further analysis has revealed that spatial receptive fields of neurons in auditory cortex, like those in the visual system, are not static but can exhibit marked temporal dynamics. This might result, for example, in a neuron becoming selective for the direction and speed of moving auditory sound sources. Our results show that approximately 14% of AI neurons evidence significant space-time interaction (inseparability).

Acoustic Stimulation↗
PubMed2004

Effect of prenatal species-specific and music stimulation on the postnatal auditory preference of domestic chick.

Perinatal sensory experience plays an important role in the development of perceptual preferences. In the present study prenatal enrichment with sound stimulus was given to see its effect on the development of postnatal auditory preference. Auditory stimulation with either species-specific (chicken maternal and hatching calls) or music (slow and fast sitar music) sounds was provided to two separate sets of fertilized eggs from the day 10 of incubation. The postnatal auditory preference of the chicks to either species-specific or music sounds was then tested at different time periods after hatching. All the chicks, irrespective of the type of prenatal exposure, showed preference for species-specific maternal calls. Notably, the music stimulated chicks did not show preference for either slow or fast music. In both the experimental groups, the number of chicks responding to the species-specific maternal calls was significantly (P<0.001) more at 24 h and 48 h post hatch, when compared with the unstimulated control group. Comparison of the species-specific stimulated group with the music stimulated group, for auditory preference to the maternal calls, did not show any significant difference. Further, in the species-specific sound stimulated groups, there was a significant (P<0.001) increase in the number of chicks responding to maternal calls at 60 h of age with repeated testing. However, there was no effect of peer imprinting on the auditory preference of the chicks, in both the experimental groups. The results indicate that prenatal auditory experience with either species-specific or non-specific music enhances the postnatal auditory preference of chicks for the species-specific sounds.

Acoustic Stimulation↗
PubMed2006

Auditory functions in children at schools for the deaf.

OBJECTIVE: To evaluate auditory functions in children at schools for the deaf in Turkey. DESIGN: A total of 218 children who were attending the school for deaf children were involved in the study. Familial and medical histories were obtained, and otoscopic examinations were performed. Immittance audiometry, acoustic reflex testing, pure tone audiometry, otoacoustic emission and auditory brain stem response tests were performed. RESULTS: The mean age of identification of hearing loss was 48 months. Impacted wax was the most common otoscopic finding that was seen in 49 (22.47%) of children. Nontype-A tympanograms were found in 18 (8.25%) of children. One-hundred-eighty-nine (86.69%) children had profound hearing loss, and 29 (10.3%) had severe hearing loss on pure tone audiometry. On auditory brain stem response testing, 192 (88.07%) children had profound hearing loss, and 26 (11.41%) had severe hearing loss. Only one child had auditory neuropathy/dys-synchrony, as his otoacoustic emission results were normal without synchronous auditory brain stem responses. The hearing threshold levels were found >105 dB in 28 children only with pure tone audiometry. CONCLUSION: Early auditory screening is necessary to identify the children at risk. All hearing disorders cannot be detected by subjective or objective audiometric tests only. Pure tone audiometry still has a role in determining hearing threshold levels. The audiological research directions should be directed towards routine pure tone audiometry, otoacoustic emission and auditory brain stem response assessment for all hearing impaired children to enable an successful treatment.

Adolescent↗
PubMed1988

Ultrasound effects on fetal auditory brain stem responses.

The use of diagnostic ultrasound raises questions regarding its bioeffects upon fetal auditory function. This study was designed to determine whether ultrasound produces changes in the auditory brain stem response in fetal lambs. Near-term fetal lambs were chronically instrumented with electroencephalogram electrodes at the vertex and the right mastoid region. An earphone was secured in the fetal right external ear canal for auditory stimulation. An ATL mechanical sector scanner was used for all ultrasound studies at a spatial peak, temporal average intensity of 15.5 mW/cm2. Auditory brain stem responses were recorded at five and 15 minutes during pulsed-wave ultrasound exposure of the cranium and then 30 minutes after cessation of insonation. Sham experiments (without insonation) were then performed in a similar time sequence to rule out the effects of habituation. There was a consistent decrease in the mean amplitude and a consistent increase in the mean latency of all five wave deflections of the auditory brain stem response during insonation. These changes persisted for 30 minutes following cessation of insonation, after which auditory brain stem response amplitude and latency values returned toward control values. No changes in auditory brain stem response amplitude or latency were observed during sham experiments. We conclude that direct ultrasound exposure of the fetal cranium through the maternal abdominal wall may temporarily influence nerve conduction along central nervous system axonal pathways. This transient influence is reversible, with all values approaching baseline within 30 minutes.

Animals↗
PubMed1979

Auditory targeting reflexes: their determining role in directional instrumental responding.

Two groups of normal dogs have been trained in a task involving one directional alimentary response signalled by the auditory cue. The cue was spatially contiguous with response in one group, and spatially discontiguous in the other. Both groups did not differ in the acquisition rate. However, as it was demonstrated in the test trials, the response of the first group was determined by the location of the cue and not by its auditory quality, while the response of the second group was based on the auditory pattern of the cue and not on its location. On this basis it may be concluded, that depending on stimulus-response spatial contiguity, different properties of an auditory stimulus play a determining role in the performance of directional response. These results support earlier anatomical and electrophysiological data pointing out to the two divisions within the auditory system, one involved in localization and another in pattern recognition of the auditory cue. The difference in the determining role of these two aspects of the auditory cue is also discussed with regard to the system of targeting reflexes, elaborated in Konorski's "Integrative activity of the brain".

Animals↗
PubMed1979

Reducing auditory feedback and the acquisition of motor response timing.

Three groups of subjects (n=10) attempted to move a lever 50 cm along a track in 1.50 sec under one of three auditory feedback conditions: Fully augmented increasing auditory feedback (FAF) in which a constant level of velocity-related auditory feedback was provided for all 25 learning trials, reducing auditory feedback (FAF) in which the level of feedback was progressively reduced over the learning trials, and no auditory feedback (NAF). All subjects performed 10 trials with no auditory feedback after a 10-min rest interval. The hypothesis that acquisition of the criterion task would be facilitated under RAF compared to FAF derived partial support. It was concluded that there is sufficient evidence to justify further investigation of reducing auditory feedback as a technique of motor skill acquisition.

Auditory Perception↗