Masking Level Differences: Auditory Evoked Responses with Homophasic and Antiphasic Signal and Noise

1979 ◽  
Vol 22 (2) ◽  
pp. 403-411 ◽  
Author(s):  
A. Yonovitz ◽  
C. L. Thompson ◽  
Joseph Lozar

Two studies were devised to determine if objective quantification of the masking level difference is possible using the auditory evoked response (AER). In the first study, click stimuli were presented under three conditions: both the stimulus and masker in phase (SoNo); stimulus in phase, masker antiphasic (SoN π ); and stimulus antiphasic with masker in phase (S π No). In the second study 1000 Hz pure-tone stimuli were presented under SoNo and S π No phasic conditions. AER’s were obtained at various intensity levels for each condition. The AER demonstrated differences in N 1 -P 2 amplitudes evoked by the homophasic and antiphasic conditions for threshold and suprathreshold levels.

1966 ◽  
Vol 9 (2) ◽  
pp. 266-272 ◽  
Author(s):  
Geary A. McCandless ◽  
Lavar Best

Selected pure tones were used as stimuli in a study of evoked auditory responses in 25 adults. The effects of stimulus frequency, intensity, and duration on the evoked response were evaluated. Pure-tone stimuli appear to be as satisfactory as click stimuli in eliciting auditory evoked responses and have the additional advantage of providing more information relative to auditory function. Evoked response patterns were essentially the same for 500 Hz (cps), 2,000 Hz, and 4,000 Hz. Latencies were longer for the components of pure-tone-evoked responses than for click-evoked responses. Evoked responses may be influenced by (1) changes in stimulus parameters and (2) changes in subject’s psychophysical state. These variables become a major consideration in the recognition of the evoked response at intensity levels near threshold.


1989 ◽  
Vol 76 (4) ◽  
pp. 415-417 ◽  
Author(s):  
Y. Shvili ◽  
U. Gafter ◽  
Y. Zohar ◽  
Y. P. Talmi ◽  
J. Levi

1. Chronic renal failure was induced in rats by five-sixths nephrectomy. Brainstem auditory evoked response (BAER) was recorded after 3 months. 2. In the uraemic rats latency of the first wave was delayed, while the interpeak I-V latency was similar to that of the controls. 3. These results suggest a delayed neural conduction along the acoustic nerve or cochlear changes in uraemic rats.


1973 ◽  
Vol 16 (4) ◽  
pp. 637-641 ◽  
Author(s):  
Michael F. Dorman ◽  
Robert Hoffmann

Short-term habituation of the vertex auditory evoked response was studied in six infants (age 10 to 14 weeks). The infants were presented trains of four synthetic speech stimuli. The average amplitude of the evoked responses was largest to the first member of the stimulus train and then decreased rapidly. The average amplitudes to the second, third, and fourth stimuli in the train were 36, 41, and 22% of the first stimulus amplitude, respectively. The results suggest that the auditory evoked response of awake infants satisfies several of the criteria for short-term habituation.


Acta Acustica ◽  
2021 ◽  
Vol 5 ◽  
pp. 43
Author(s):  
Felix Dymel ◽  
Monika Kordus ◽  
Ifat Yasin ◽  
Jesko L. Verhey

The present study investigates how diotic and dichotic masked thresholds, in a notched-noise masking paradigm, are affected by activation of the Medial OlivoCochlear (MOC) reflex. Thresholds were obtained for a 500-Hz pure tone diotic or a dichotic signal, S (S0 or Sπ respectively), in the presence of a simultaneous or forward diotic masker (bandpass noise with no notch or a 400-Hz notch). A diotic precursor sound (bandpass noise with a 400- or 800-Hz notch) was presented prior to the signal and masker to activate the MOC reflex. For simultaneous- and forward-masking conditions, the decrease in masked thresholds as a notch was introduced in the masker was larger for the diotic than for the dichotic condition. This resulted in a reduced binaural masking level difference (BMLD) for the masker with a notch. The precursor augmented these two effects. The results indicate that the effect of the precursor, eliciting the MOC reflex, is less pronounced when binaural cues are processed.


2019 ◽  
Vol 145 (3) ◽  
pp. 1721-1722
Author(s):  
Daniel E. Shub ◽  
Joshua G. W. Bernstein ◽  
Lina R. R. Kubli ◽  
Douglas S. Brungart ◽  
Ken W. Grant

1982 ◽  
Vol 40 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Carlos A. M. Guerreiro ◽  
Bruce L. Ehrenberg

The tecnique that we use for eliciting brainstem auditory evoked responses (BAERs) is described. BAERs are a non-invasive and reliable clinical test when carefully performed. This test is indicated in the evaluation of disorders which may potentially involve the brainstem such as coma, multiple sclerosis posterior fossa tumors and others. Unsuspected lesions with normal radiologic studies (including CT-scan) can be revealed by the BAER.


1993 ◽  
Vol 36 (2) ◽  
pp. 442-447
Author(s):  
Gerald Kidd ◽  
Robert F. Burkard ◽  
Christine R. Mason

The human brainstem auditory evoked response (BAER) is a far-field electrical potential recorded from the scalp in response to transient acoustic stimuli. Typically, voltage measurements are obtained for a period of about 10 msec following the acoustic stimulus, which is repeated and summed several hundred or thousand times to permit extraction of the response from ongoing nonauditory neural activity. The judgment about whether a response has been obtained is normally based on the pattern observed in a visual display of the waveform. In this study, we investigated whether listeners can distinguish BAERs elicited by acoustic clicks from control waveforms obtained with no acoustic stimulus when the waveforms were presented auditorily. For this purpose, BAER and control waveforms were transduced by an earphone and used in an auditory detection task. Several presentation strategies were examined, including lengthening the waveform by playing it at a lower sampling rate, playing the waveform repetitively, and using the waveform to frequency modulate a pure-tone carrier. The results indicated that the BAER, when extended in duration and used to frequency modulate a 1000-Hz pure tone, was highly detectable in a yes-no paradigm for BAERs elicited with high-level (e.g., 70 dB re. behavioral detection threshold) acoustic clicks. Performance declined to near chance as the level of the BAER-eliciting stimulus was lowered to 10 dB. In general, detection performance for stimuli presented visually was slightly, but consistently, superior to that which occurred for stimuli presented auditorily.


1984 ◽  
Vol 49 (2) ◽  
pp. 114-127 ◽  
Author(s):  
Randall C. Beattie ◽  
Margaret Moretti ◽  
Virginia Warren

Auditory evoked responses to tone pips were recorded on 10 normally hearing adults. Tone pips centered at 500 and 2000 Hz with 1, 2, and 4 ms rise-fall times were presented at intensities of 40, 30, 20, and 10 dB nHL. The band-pass of the recording-amplifier system was set to 55 and 3000 Hz. Responses were measured during the first 25 ms following the onset of the stimulus and the first three prominent waves were labeled P10, N15, and P20. The results indicated that varying rise-fall times from 1 to 4 ms had little effect on the detectability of these waves. Consequently, the 4-ms rise-fall time was recommended because of its greater frequency specificity. The number of identifiable responses was similar for both 500 and 2000 Hz for waves P10, N15, and P20. The similarity in the number of detectable responses suggests that any of these waves may be used as a threshold indicator. The acoustic/physiologic mechanisms underlying the latency changes are discussed.


1983 ◽  
Vol 91 (1) ◽  
pp. 50-60 ◽  
Author(s):  
James W. Hall ◽  
Musan Huangfu ◽  
Thomas A. Gennarelli ◽  
Carol A. Dolinskas ◽  
Kristine Olson ◽  
...  

Three case studies are presented to illustrate the clinical usefulness of serial electrophysiologic and behavioral audiologic assessments in describing CNS function in severe head injury. There was an association among acute auditory brain stem and middle-latency evoked response findings, computed tomography of brain abnormality and neurologic status, and rate of recovery. Auditory evoked response findings 4 days after injury were also correlated with long-term outcome of diagnostic speech audiometry.


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