ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

A dichotic digit test was administered to 21 subjects with intracranial lesions. Twelve subjects had lesions limited to the cortex and nine had brain stem disorders. The dichotic digit test appeared to be a sensitive measure for detecting cortex and brain stem lesions. Laterality data indicated markedly reduced performance for the ear contralateral to the hemispheric lesion. Overall results were similar to previous reports on dichotic digits, supporting the use of this test as a screening procedure or part of a test battery for CNS evaluation.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The test-retest reliability of hearing thresholds at 1000 Hz measured by a delayed auditory feedback procedure was compared with the reliability of thresholds obtained with voluntary responses to the same signal in 10 adults with normal hearing sensitivity. Thresholds for each procedure were obtained three times on each of 5 different days. Although the delayed feedback procedure yielded estimates of threshold which averaged 4.6 dB greater than those estimated by voluntary responses (p <0.05). There was no evidence that experience over time resulted in a change for the poorer in the precision of the test.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Telephone handsets have a built-in side-tone feedback because the transmitter feeds back sound through the receiver, allowing users to monitor their voice levels. However, the side-tone feedback system also picks up background noise which interferes with the incoming speech signal. This study investigated the influence of side-tone feedback on the telephone listening ability of 30 normal-hearing subjects in a background of multitalker (MT) and white noise (WN) presented at 65, 75, and 85 dB SPL in two conditions where the side-tone feedback was present and in three conditions where the side-tone was eliminated. Telephone listening ability significantly decreased as the level of the noise increased for both MT and WN and for all listening conditions. Telephone listening ability was significantly poorer in the background of MT than WN for each noise level and listening condition. The primary finding was that telephone listening ability in a background of MT or WN at the higher levels was significantly improved when the side-tone feedback was eliminated by electronically disengaging or more simply by occluding the transmitter with the palm of the hand.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The interlist equivalency of the CID W-22 word lists administered in quiet and in a background of noise was investigated using 48 normal-hearing subjects. All four word lists were administered at 20 dB SL in quiet and in the presence of a multitalker babble (0 dB signal-to-noise ratio). In the statistical analyses, word performance and subject performance were used as the dependent measures. The results indicated that: (1) the lists are equivalent when administered in quiet; (2) the lists are not equivalent when administered in a background of multitalker babble; (3) the addition of noise changes the relationship among the word lists in a nonpredictive manner; and (4) the addition of noise changes the level of difficulty of some words of each list to a greater degree, relative to the other words. The results are discussed relative to their implications for hearing evaluation and hearing aid evaluation procedures.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

High-frequency sensitization of the acoustic reflex was studied in 10 normal-hearing subjects. The procedure involved pairing a subreflex 6000 Hz sensitizing tone with activating frequencies of 500.1000, and 2000 Hz. Both threshold and growth of amplitude of the acoustic reflex were examined. Acoustic reflex threshold was reduced by an average of 10 to 12 dB in the presence of a 6000 Hz sensitizing tone, an amount significantly less than previously reported in similar investigations. Variations in the method used to adjust the presentation level of the high-frequency sensitizing tone probably account for these differences. Growth of acoustic reflex amplitude was also found to be influenced by sensitizing stimulation, with the greatest effect occurring near acoustic reflex threshold.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The effect of approach mode (ascending versus descending, A-D) on comfortable loudness was determined for a 1000 Hz pure tone using Bekesy audiometry. Two groups (experimental and control) of 10 normal-hearing young adult subjects measured their most comfortable loudness (MCL) levels pre-and post-treatment. The experimental group received a treatment of a listening exposure to a 70 dB intensity range before the test. The results demonstrated a statistically significant change of the A-D gap in the experimental group while the A-D gap for the control group remained essentially unchanged. It is proposed that MCL is underestimated in the ascending approach and overestimated on the descending testing, which results in the A-D gap. In addition, the results demonstrate the importance of the procedures used in research and clinic of the MCL.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

ABR results from 400 newborns were examined for skin contact-electrode impedance effects on screening results. Neither high electrode impedance nor unbalanced impedance between the active electrodes appeared to have a significant effect on the screening results. Caution is advised in interpreting the results of this study. The authors are not advocating poor skin-electrode contact. However, satisfactory responses have been recorded with higher than previously reported optimal electrode impedance.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

A single case is reported of a severely hearing-impaired child with a finding of a large air-bone gap on pure-tone audiometry on multiple tests. Exploratory surgery found normal middle ear function. Subsequent audiometry indicated the presence of a false air-bone gap resulting from vibrotactile responses. Test procedures for identifying vibrotactile responses are discussed.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Digital filters that have been in clinical use for about 3 yrs are described, and their effects on the waveforms of brain stem auditory evoked potentials and their ability to suppress noise are compared to the effects of analog filters on brain stem auditory evoked potential waveforms and the ability of analog filters to suppress noise.

ISSN:0196-0202    

出版商:OVID    

年代:1983

数据来源: OVID