摘要:

The purpose of this study was to investigate auditory-stimulus effects on head-turn response behavior of infants under conditions where responses were either reinforced or not reinforced with a visual stimulus. The auditory stimuli contained different frequency bandwidths between 2000 and 4000 Hz. The stimulus with the widest bandwidth resulted in more responses than the other two stimuli in the no-reinforcement condition. When conditioning was established and all responses were visually reinforced, there was no difference in response behavior among stimulus groups for either suprathreshold or threshold stimulation. These findings have implications for clinical assessment using visual reinforcement audiometry. Results suggest that bandwidth characteristics of the auditory stimulus have no influence on response behavior of infants providing conditioning can be established and maintained through the use of visual reinforcement.

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The cochlear summating potential (SP) preceding the auditory nerve compound action potential (AP) was elicited by broadband alternating condensation and rarefaction clicks and recorded by noninvasive electrodes from the external auditory meatus (EAM) of 60 volunteers of both sexes, 12 to 67 years old, who had normal hearing for age. Quantitative data were obtained on: the number of ears displaying measurable SPs; the SP detection level; the SP onset, peak and rise times; the duration of the SP-AP complex; the SP amplitude; and the SP/AP amplitude ratio. Previously unknown relationships were unveiled between the amplitude, but not the temporal, measures of the SP and laterality, sex, age, and audiometrically determined hearing thresholds to 4 to 8 kHz tones. The highest correlations were obtained with these last thresholds, which suggested that receptors in the basal turn of the cochlea played a dominant role in the generation of the EAM-detected SP. To improve on existing techniques for determining abnormal SP elevation, a multiple regression method was devised that utilized sex, age, 4 to 8 kHz hearing thresholds, and AP voltage to establish upper normal limits of SP amplitude for individual subjects and ears.

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The effect of decreased anterior (carotid) bloodflow on the auditory brain stem response (ABR) was studied in a group of middle-aged males with angiographically confirmed decreased carotid circulation who were candidates for internal carotid end-arterectomy. Individual and mean latencies from the experimental group were compared to latencies of a control group matched for age, sex, and hearing loss. Mean absolute latency of wave V was significantly longer in the group with decreased anterior circulation when compared to the matched control group. These findings are similar to those from studies examining decreased posterior (vertebrobasilar) circulation. Both the matched control and experimental group were also compared to clinic norms and judged for abnormality. None of the control group ABRs were judged abnormal, after correction for hearing loss, while 29% of the ABRs were judged abnormal from the group with decreased anterior circulation. Postoperative testing was performed 1 week after surgery to determine any immediate effects of revascularization of the ABR. No changes in absolute or interpeak latencies were observed for either ear between pre-and postoperative testing. It is concluded that patients with confirmed decreased cerebrovascular Circulation may show prolongation of absolute latency of wave V on ABR testing. Revascularization surgery in these patients appears to have no affect on their ABR within 1 week of surgery.

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The use of objective (mathematical) procedures in auditory brain stem response (ABR) testing has been suggested in order to eliminate the subjectivity of visual judgments and to increase sensitivity of detection. This investigation compared with effectiveness of visual and objective detection of the ABR. Auditory brain stem responses were obtained in normal adults at several click levels. An equal number of waveforms obtained without stimulation were used to measure false-positive responses. Visual judgments of ABR presence were made by four experienced raters. Objective analysis was accomplished using three methods: correlation, variance ratio, and multiple pre-post z tests. The mean sensitivity score was highest for visual detection, followed in order by the correlation, variance ratio, and multiple z test methods. While visual scoring was statistically the most sensitive, the practical difference between measures was small. In addition, there was considerable disagreement between raters in their judgments. Therefore, the most sensitive of the objective measures—correlation, is considered to be a useful detection procedure to eliminate observer bias and to achieve consistency of scoring.

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The nature of functional hearing loss was retrospectively studied with respect to hearing sensitivity after resolution of the nonorganic components in 63 adults with bilateral exaggerated losses (126 ears). The configuration of the functional components (difference between the functional and resolved thresholds) was found to be related to that of the resolved hearing levels. The size of the functional overlay was essentially the same across the audiometric frequency range when the hearing was actually normal or if there was only mild loss. In cases of precipitously sloping high-frequency losses, the magnitude of the functional overlay became dramatically smaller for the impaired frequencies than for lower frequencies where hearing was normal or only mildly impaired. Moderate and severe losses represented a transitional situation, in which the functional components became gradually smaller with increasing frequency. Subjects with different resolved hearing in each ear (e.g., mild loss in one ear and a precipitous loss in the other) demonstrated nonorganic overlays that were consistent with the actual hearing levels for each respective ear. The findings suggest the use of an internalized, loudness level-based anchor by subjects with functional losses: the test signal must sound as loud as the anchor at each frequency in order for an exaggerated threshold response to be volunteered at that respective frequency. The pure-tone audiometric configuration and amount of functional loss at least in bilateral cases is thus consistently accounted for on the basis of known and explainable auditory factors.

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

This study reports the findings of a survey of retirees age 65 and older, involving scaled responses to 35 possible reasons for rejection of hearing aid use. The foremost reasons for nonuse of hearing aids included cost, calling attention to the handicap, dealer practices, concern about the nature of the amplified sound, difficulty manipulating hearing aid controls, and not knowing where to obtain a hearing aid.

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The human auditory steady state evoked potentials were recorded during all-night sleep in 10 subjects. The effects of stimulus rate and intensity on these potentials were measured using on-line Fourier analysis. The amplitude of the response was greatest at stimulus rates of 30 to 50/sec. Although the response amplitude was lower during sleep, the rate at which the amplitude was greatest did not change between sleep and wakefulness. As the intensity was increased above threshold, the amplitude of the response increased linearly. The responses recorded during wakefulness showed a larger amplitude change with increasing intensity than during sleep. The estimated thresholds for the responses, however, did not differ significantly between wakefulness and sleep.

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0196-0202    

出版商:OVID    

年代:1985

数据来源: OVID