PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Auditory Perception”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 937 records · Page 52Linked to original sources
PubMed1987

Infants' localization of sounds in the median vertical plane: estimates of minimum audible angle.

Infants 6, 9, 12, 15, and 18 months of age were seated in a dark room directly facing an array of nine loudspeakers positioned along the median vertical plane. One loudspeaker was positioned at ear level, 0 degree, and four others each were positioned above and below 0 degree. To examine infants' resolution of auditory space in the median vertical plane we sought to determine the smallest angular shift in the vertical location of a sound that infants could reliably detect (i.e., minimum audible angle). A two-alternative forced-choice procedure was used in which a sequence of white noise bursts was presented initially at 0 degree, and then shifted vertically (i.e., above or below 0 degree) and continued to be presented until the infant made a directional response; correct responses were visually reinforced. The smallest angular shift in vertical location that was reliably detected systematically decreased with increasing age between 6 months (15 degrees) and 18 months (4 degrees), suggesting a finer partitioning of auditory space along the vertical axis over this age range. By 18 months infants' performance matched that of a group of adults tested under the same circumstances.

Auditory Perception↗
PubMed1988

Fetal hearing.

The fetus can hear during the last trimester of pregnancy. Consistent responses to acoustic stimuli have been observed from 28 weeks onwards. Animal experiments as well as investigations in the human lead to the conclusion that sounds from outside the mother are attenuated, but rarely by more than 30 decibels; external conversations are audible. Only 30% of the phonetic information is available to the fetus, but intonation is almost perfectly transmitted to the amniotic sac. Evidence is accumulating that the mother's voice or different sound patterns from the same voice are learnt by the fetus. Thus there are indications that short-term auditory memory may be present by the end of pregnancy.

Auditory Perception↗
PubMed1992

EEG and EMG responses to emotion-evoking stimuli processed without conscious awareness.

Dichotic stimulus pairs were constructed with one word that was emotionally neutral and another that evoked either negative or positive feelings. Temporal and spectral overlap between the members of each pair was so great that the two words fused into a single auditory percept. Subjects were consciously aware of hearing only one word from most pairs; sometimes the emotion-evoking word was heard consciously, other times the neutral word was heard consciously. Subjects were instructed to let their thoughts wander in response to the word they heard, during which time EEG alpha activity over left and right frontal regions, and muscle activity (EMG) in the corrugator ("frowning") and zygomatic ("smiling") regions were recorded. Both EEG and EMG provided evidence of emotion-specific responses to stimuli that were processed without conscious awareness. Moreover both suggested relatively greater right hemisphere activity with unconscious rather than conscious processing.

Adolescent↗
PubMed1989

Cortical deafness cannot account for the inability of Japanese macaques to discriminate species-specific vocalizations.

Bilateral ablation of the superior temporal gyrus in Japanese macaques results in a significant hearing loss (cortical deafness) as well as in an inability to discriminate between two types of their "coo" vocalizations. A two-part investigation was conducted to determine whether the hearing loss may itself affect the ability to discriminate vocalizations. First, four normal Japanese macaques were tested for their ability to discriminate coos which were filtered to simulate the effect of a cortical hearing loss. Second, four Japanese macaques with bilateral superior temporal gyrus lesions were tested for their ability to discriminate coos which were amplified and equalized to compensate for each animal's hearing loss. All four normal macaques were able to discriminate the filtered coos easily whereas compensating for the operated monkeys' hearing losses did not improve their performances. It appears that the inability of monkeys with bilateral superior temporal gyrus lesions to discriminate conspecific vocalizations is not simply due to the accompanying hearing loss, but is a separate auditory disorder.

Animals↗
PubMed1981

Lateralized auditory processing in depression: dichotic click detection.

The intensity needed to detect dichotic click stimuli was measured in 14 bipolar depressed patients, 19 unipolar depressed patients, and 15 normal controls. The results replicated, in unmedicated bipolar depressed patients, an earlier finding of reversed lateral asymmetry in medicated affective psychotic patients. Two new findings concern the relation of lateral asymmetry patterns to diagnostic subtypes of the Research Diagnostic Criteria and symptom ratings on the Schedule for Affective Disorders and Schizophrenia. First, patients with bipolar disorders (history of mania or hypomania) were more likely than patients with unipolar disorders to display reversed lateral asymmetry. Second, greater severity of depressive or endogenous symptoms was associated with less lateral asymmetry.

Adult↗
PubMed1993

Lateral asymmetries in auditory acuity distinguish hallucinating from nonhallucinating schizophrenic patients.

Bilateral absolute auditory thresholds for frequencies ranging from 250 to 8000 Hz were examined on two occasions in schizophrenic patients and normal control subjects. Patients were classified as hallucinators and nonhallucinators on the basis of symptom ratings on both occasions. Previous evidence of better right than left ear acuity in schizophrenia was replicated but was found to characterize nonhallucinating patients only. Hallucinators showed no lateral asymmetry and inferior right ear acuity as compared with that in nonhallucinators. The results were reliable on retest. Brief Psychiatric Rating Scale scores of positive and negative symptoms in some cases differentiated hallucinators from nonhallucinators. The relationship of verbal hallucinations and right ear-left temporal lobe functions is discussed, together with complexities in cerebral laterality-syndrome relationships.

Adult↗
PubMed1991

Evoked otoacoustic emissions in infant hearing screening.

The main application of the ILO88 otodynamic otoacoustic analyser is clearly in detecting whether the peripheral auditory system is normal or pathological. The evoked otoacoustic emission technique in normal and hearing-impaired children for which audiometric data were known (n = 422 ears) was first performed. The correlation was excellent. The actual experimental group (n = 258 ears) consisted of children who are difficult to test with the conventional screening methods in school health services. The use of evoked otoacoustic emissions as screening instrument is new, and therefore several minimal practical criteria, advantages and limitations were defined. The evoked otoacoustic emission test tool is especially applicable in difficult to test children using conventional screening methods.

Acoustic Impedance Tests↗
PubMed1996

Evolution of transient evoked otoacoustic emissions in preterm newborns: a preliminary study.

Transient evoked otoacoustic emissions (TEOEs) were recorded in a cohort study of preterm neonates in order to study their basic properties as a function of gestational age. Their main properties were: (1) TEOEs spectrum did not vary with age; it was analogous to those of full term; (2) there was no statistically significant variation of the TEOEs amplitude with age. The maturation of outer hair cell properties appears to be complete at a gestational age of 29 weeks. Because a number of infants at risk for hearing loss are preterm babies, screening for TEOEs has to be performed in the neonatal care unit. To improve the accuracy and efficiency of the test, screening should take place as close to hospital discharge as possible, with the optimum time at 35 gestational weeks.

Analysis of Variance↗
PubMed1994

Visual processing, lateralization and syndromes of schizotypy.

There is an association between positive features of schizotypy and dyslexia, largely involving distortions of visual and auditory perception and associated cognitive anomalies. In dyslexia, there is strong evidence for a disorder of subcortical magnocellular pathways, which may underlie these perceptual aberrations. Here we investigated visual processing in relation to three syndromes of schizotypy-Active, Withdrawn and Unreality-in normal adults, using a "dot localization" test of visual direction sense on which dyslexics perform poorly, and which should be sensitive to magnocellular dysfunction. Results showed that increased error scores were associated with both the positive syndromes, Active and Unreality, which in this study were highly correlated. There were also interactions between each syndrome and the direction of errors, such that high scorers on the Unreality and Active syndromes made more errors on leftward trials, while high Withdrawn subjects made fewer left and more right errors. Mixed handers also showed poorer performance than consistent handers. The evidence of poor visual direction sense in relation to positive syndromes of schizotypy and mixed handedness is consistent with the previous results for dyslexics, who also show these features. The opposite lateralization of errors in the positive v negative syndromes of schizotypy is in keeping with the model of hemisphere imbalance and patterns of cognitive asymmetry which distinguish Active from Withdrawn syndromes. These results are considered in relation to the proposal that a disorder of magnocellular function may underlie the perceptual distortions which are common to dyslexia and positive syndromes of schizotypy.

Adolescent↗
PubMed1991

Auditory function in young patients with type 1 diabetes mellitus.

Comprehension of the effect of diabetes mellitus on auditory function has been hindered by the fact that previous studies have evaluated hearing function in heterogeneous groups of patients with diabetes mellitus, thus giving conflicting results. We have performed audiometric studies in 46 consecutive patients. 13 with newly diagnosed type 1 diabetes mellitus (group 1) and 33 with type 1 diabetes mellitus of more than 3 years of duration (group 2), of 14 to 40 years of age. The results were compared to an age-matched control group. Pure-tone auditory thresholds were significantly higher in all frequencies 250-8,000 Hz in both groups when compared to the control subjects. Ten patients, all of which belonged to group 2, had auditory thresholds above 30 dB in at least one frequency, showing a conversational hearing loss that ranged between 11 and 44%. However, none of them referred subjective hypoacusia. Univariate analysis revealed significant associations between auditory thresholds and age, duration of disease as well as retinopathy, but not with neuropathy, HbA1c or hypoglycaemic episodes. Only age and duration of disease independently correlated with an auditory threshold using multiple regression. We conclude that type 1 diabetes mellitus can cause mild sensorineural hearing impairment which correlates with age and duration of disease.

Adult↗