Auditory Distortion Products Measured With Averaged Auditory Evoked Potentials

1992 ◽  
Vol 35 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Mark E. Chertoff ◽  
Kurt E. Hecox ◽  
Robert Goldstein
Keyword(s):  
High Frequency ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Low Frequency ◽  
Auditory Evoked Potential ◽  
Noise Floor ◽  
Distortion Products ◽  
Nonlinear Processing ◽  
Cochlear Damage ◽  
Primary Frequency

The purpose of this investigation was to describe the properties of averaged auditory evoked potential distortion products (AEP-DPs) in guinea pigs. This study provided a step toward developing a clinical index of nonlinear processing of auditory signals and supplied a baseline for studies evaluating the effect of cochlear damage on AEP-DPs. The amplitude of the AEP-DPs was evaluated as a function of f2/fl ratio (1.12–1.52) and primary frequency (500 Hz–2000 Hz). The amplitude of the AEP cubic difference tone (AEP-CDT) increased with increasing f2/fl ratio for the 500-Hz f1 primary and remained constant for the 800-Hz and 1700-Hz f1 primaries. The AEP-CDT generated by the 1100-Hz and 1400 Hz f1 primaries was maximum for the middle f2/fl ratios (1.22, 1.32, and 1.42). The AEP-CDT could not be distinguished from the noise floor for the 2000-Hz f1 primary. The AEP difference tone (AEP-DT) was larger and more frequently identified than the AEP-CDT. The amplitude of the AEP-DT decreased with an increase in f2/f1 ratio. The decrease was more pronounced for low-frequency f1 primaries than for high-frequency f1 primaries.

High-frequency Components of Auditory Evoked Potentials Are Detected in Responsive but Not in Unconscious Patients

2005 ◽  
Vol 103 (5) ◽  
pp. 944-950 ◽  
Author(s):  
Bertram Scheller ◽  
Gerhard Schneider ◽  
Michael Daunderer ◽  
Eberhard F. Kochs ◽  
Bernhard Zwissler
Keyword(s):  
Evoked Potentials ◽  
General Anesthesia ◽  
High Frequency ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
General Anesthetics ◽  
Frequency Bands ◽  
Time Frequency ◽  
Frequency Components

Background The dose-dependent suppression of midlatency auditory evoked potentials by general anesthetics has been proposed to measure depth of anesthesia. In this study, perioperatively recorded midlatency auditory evoked potentials were analyzed in a time-frequency space to identify significant changes induced by general anesthesia. Methods Perioperatively recorded auditory evoked potentials of 19 patients, recorded at varying levels of anesthesia, were submitted to a multiscale analysis using the wavelet analysis. Energy contents of the signal were calculated in frequency bands 0-57.1 Hz, 57.1-114.3 Hz, 114.3-228.6 Hz, and 228.6-457.1 Hz. A Friedman test and a Dunn multiple comparisons test were performed to identify significant differences. Results Statistical evaluation showed a highly significant decrease of the wavelet energies for the frequency bands 57.1-114.3 Hz (P < 0.0001), 114.3-228.6 Hz (P < 0.0001), and 228.6-457.1 Hz (P < 0.0001) for the measuring points representing deep general anesthesia. This decrease is accompanied by a decrease in the wavelet energy of the frequency band 0-57.1 Hz of no statistical significance (P = 0.021) (level of significance set to P = 0.01). The changes are most prominent in the poststimulus interval between 10 and 30 ms. Conclusions This study describes the presence of high-frequency components of the auditory evoked potential. The amount of these components is higher during responsiveness when compared to unconsciousness. Temporal localization of the high-frequency components within the auditory evoked potential shows that they represent a response to the auditory stimulus. Further studies are required to identify the source of these high-frequency components.

scholarly journals Hemispheric contribution to vertex augmentation/reduction of the auditory evoked potential

1985 ◽  
Vol 43 (4) ◽  
pp. 347-354 ◽  
Author(s):  
C. Collin ◽  
F. Lolas
Keyword(s):  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Right Hemisphere ◽  
Auditory Evoked Potential ◽  
Hemispheric Processing ◽  
Processing Mode ◽  
Subject Characteristic ◽  
Attention Deployment ◽  
Set Up ◽  
The Right

Starting off from the notion that the cerebral hemispheres differ in their processing mode, this paper reports on stimulus intensity modulation of auditory evoked potentials recorded from hemispheric leads (C3 and C4 referenced to ipsilateral mastoid processes) in a sample of 40 male Ss between 18 to 40 years of age. The experimental set up involved the recording of series of 100 trials to binaural clicks of 63.5, 74.6 and 85dB AL. Ss who were augmenters at the vertex showed positive Amplitude-Intensity function slopes over the left hemisphere; when Ss were Reducers at the vertex, the slopes were negative on the right hemisphere. These results are interpreted in terms of attention deployment or allocation to one or the other hemispheric processing mode. This might constitute a trait-like enduring subject characteristic whose relation to traditional psychometric variables needs further exploration. The modality especificity of this phenomenon is also discussed.

Direct brainstem recording of auditory evoked potentials during vestibular schwannoma resection: nuclear BAEP recording

1997 ◽  
Vol 86 (6) ◽  
pp. 1057-1062 ◽  
Author(s):  
Cordula Matthies ◽  
Madjid Samii
Keyword(s):  
Vestibular Schwannoma ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Conventional Technique ◽  
Auditory Evoked Potential ◽  
New Technique ◽  
Recording Site ◽  
Content Type ◽  
Direct Recording ◽  
A New Technique

✓ The usefulness of intraoperative monitoring in cerebellopontine angle surgery should be improved by obtaining faster and stronger brainstem auditory evoked potential (BAEP) responses. A new technique of direct recording at the brainstem has been developed, which is applicable to all tumor sizes. By placing a retractor with electrodes attached to its tip at the cerebellomedullary junction, the authors have recorded BAEP amplitudes that are 10 times greater than those recorded using the conventional technique. Only small sampling numbers (64–256 recordings) are required and are obtained in 5 to 15 seconds. The technique has been applied successfully in 34 patients who underwent vestibular schwannoma resections. It has also been tested in patients with intrameatal—extrameatal meningiomas and in those with vascular compressive disorders; there have been no false results. The advantages of this new technique are: 1) identification of BAEP components is easier and faster; 2) reliable BAEP responses are obtained in some cases in which conventional BAEP responses are lost or severely deformed; and 3) BAEP response deterioration and improvement are recognized earlier than would occur using the conventional technique. This last advantage provides the surgeon with a useful warning at a stage of surgery at which BAEP changes are still temporary and can be reversed. This method is different from other trials of intradural BAEP recordings in three respects: its use is not limited to particular tumor sizes; there is no interference with the surgical process; and, most important, the obtained responses correlate well with those of conventional BAEP responses, probably because the recording site is in the vicinity of the anterior cochlear nucleus. In conclusion, the chances of useful monitoring feedback with adequate adaptation of the microsurgical strategy are improved considerably.

scholarly journals Parameters for Applying the Brainstem Auditory Evoked Potential with Speech Stimulus: Systematic Review

2017 ◽  
Vol 22 (04) ◽  
pp. 460-468 ◽  
Author(s):  
Luísa Gabriel ◽  
Luíza Vernier ◽  
Maria Ferreira ◽  
Adriana Silveira ◽  
Márcia Machado
Keyword(s):  
Systematic Review ◽  
Evoked Potentials ◽  
Brain Stem ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Sampling Rate ◽  
Presentation Rate ◽  
Auditory Evoked Potential ◽  
Speech Stimulus ◽  
Brainstem Auditory Evoked Potential

Introduction Studies using the Brainstem Auditory Evoked Potential with speech stimulus are increasing in Brazil, and there are divergences between the methodologies used for testing. Objectives To analyze the parameters used in the study of the Brainstem Auditory Evoked Potentials with speech stimulus. Data Synthesis The survey was performed using electronic databases. The search strategy was as follows: “Evoked potentials, auditory” OR “Brain stem” OR “Evoked potentials, auditory, brain stem” AND “Speech.” The survey was performed from June to July of 2016. The criteria used for including articles in this study were: being written in Portuguese, English or Spanish; presenting the description of the testing parameters and the description of the sample. In the databases selected, 2,384 articles were found, and 43 articles met all of the inclusion criteria. The predominance of the following parameters was observed to achieve the potential during study: stimulation with the syllable /da/; monaural presentation with greater use of the right ear; intensity of 80 dB SPL; vertical placement of electrodes; use of in-ear headphones; patient seated, distracted in awake state; alternating polarity; use of speech synthesizer software for the elaboration of stimuli; presentation rate of 10.9/s; and sampling rate of 20 kHz. Conclusions The theme addressed in this systematic review is relatively recent. However, the results are significant enough to encourage the use of the procedure in clinical practice and advise clinicians about the most used procedures in each parameter.

scholarly journals Cortical Auditory Evoked Potentials with Simple (Tone Burst) and Complex (Speech) Stimuli in Children with Cochlear Implant

2017 ◽  
Vol 21 (04) ◽  
pp. 351-357
Author(s):  
Kelly Vasconcelos Martins ◽  
Daniela Gil
Keyword(s):  
Cochlear Implant ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Tone Burst ◽  
Auditory Evoked Potential ◽  
Aural Rehabilitation ◽  
Auditory Rehabilitation ◽  
Complex Stimuli ◽  
Significant Difference ◽  
Cortical Auditory Evoked Potential

Introduction The registry of the component P1 of the cortical auditory evoked potential has been widely used to analyze the behavior of auditory pathways in response to cochlear implant stimulation. Objective To determine the influence of aural rehabilitation in the parameters of latency and amplitude of the P1 cortical auditory evoked potential component elicited by simple auditory stimuli (tone burst) and complex stimuli (speech) in children with cochlear implants. Method The study included six individuals of both genders aged 5 to 10 years old who have been cochlear implant users for at least 12 months, and who attended auditory rehabilitation with an aural rehabilitation therapy approach. Participants were submitted to research of the cortical auditory evoked potential at the beginning of the study and after 3 months of aural rehabilitation. To elicit the responses, simple stimuli (tone burst) and complex stimuli (speech) were used and presented in free field at 70 dB HL. The results were statistically analyzed, and both evaluations were compared. Results There was no significant difference between the type of eliciting stimulus of the cortical auditory evoked potential for the latency and the amplitude of P1. There was a statistically significant difference in the P1 latency between the evaluations for both stimuli, with reduction of the latency in the second evaluation after 3 months of auditory rehabilitation. There was no statistically significant difference regarding the amplitude of P1 under the two types of stimuli or in the two evaluations. Conclusion A decrease in latency of the P1 component elicited by both simple and complex stimuli was observed within a three-month interval in children with cochlear implant undergoing aural rehabilitation.

scholarly journals A STUDY ON SOMATOSENSORY EVOKED POTENTIAL PATTERNS ACCORDING TO VARIOUS VIBROTACTILE STIMULATION: FREQUENCIES AND INTENSITIES

2020 ◽  
Vol 20 (09) ◽  
pp. 2040015
Author(s):  
MI-HYUN CHOI ◽  
JIN-JU JUNG ◽  
JE-HYEOP LEE ◽  
HYUNG-SIK KIM ◽  
HYUN-JUN KIM ◽  
...  
Keyword(s):  
High Frequency ◽  
Evoked Potential ◽  
Index Finger ◽  
Low Frequency ◽  
Clinical Applications ◽  
Distal Phalanx ◽  
Somatosensory Evoked Potential ◽  
Vibrotactile Stimulation ◽  
Somatosensory Area ◽  
Normal Cognitive Function

This study investigates somatosensory evoked potential (SEP) patterns in the C3 somatosensory area with varying frequency and intensity of vibrotactile stimuli. The study subjects included 13 men ([Formula: see text] years) and seven women ([Formula: see text] years) who were right-handed and had normal cognitive function. The participants were subjected to three intensity levels (0.25, 0.38 and 1.3[Formula: see text]g) and eight frequencies (10, 50, 100, 150, 200, 225, 250 and 300[Formula: see text]Hz) of vibrotactile stimuli on the distal phalanx of their right index finger. The peak values of SEP patterns generated in response to high-frequency vibrotactile stimuli were greater than those generated because of low-frequency flutter. Moreover, the peak values increased as the stimulus intensity increased from 1[Formula: see text]g to 3[Formula: see text]g. In these results, the maximum and minimum peak, and peak to peak values of SEP pattern in the C3 somatosensory area increased with an increase in the stimulation intensity and frequency of the vibrotactile stimuli. Data on the SEP patterns generated in response to various frequencies and intensities of somatosensory stimuli and the development of relevant databases will elucidate the various clinical applications and applicable domains where SEP assessment can be beneficial.

scholarly journals Abnormalities in auditory evoked potentials of 75 patients with Arnold-Chiari malformations types I and II

2006 ◽  
Vol 64 (3a) ◽  
pp. 619-623 ◽  
Author(s):  
Paulo Sergio A. Henriques Filho ◽  
Riccardo Pratesi
Keyword(s):  
Evoked Potentials ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Amplitude Ratio ◽  
Auditory Evoked Potential ◽  
Type I ◽  
Auditory Pathways ◽  
Degree Of Severity ◽  
Chiari Malformations

OBJECTIVE: To evaluate the frequency and degree of severity of abnormalities in the auditory pathways in patients with Chiari malformations type I and II. METHOD: This is a series-of-case descriptive study in which the possible presence of auditory pathways abnormalities in 75 patients (48 children and 27 adults) with Chiari malformation types I and II were analyzed by means of auditory evoked potentials evaluation. The analysis was based on the determination of intervals among potentials peak values, absolute latency and amplitude ratio among potentials V and I. RESULTS: Among the 75 patients studied, 27 (36%) disclosed Arnold-Chiari malformations type I and 48 (64%) showed Arnold-Chiari malformations type II. Fifty-three (71%) of these patients showed some degree of auditory evoked potential abnormalities. Tests were normal in the remaining 22 (29%) patients. CONCLUSION: Auditory evoked potentials testing can be considered a valuable instrument for diagnosis and evaluation of brain stem functional abnormalities in patients with Arnold-Chiari malformations type I and II. The determination of the presence and degree of severity of these abnormalities can be contributory to the prevention of further handicaps in these patients either through physical therapy or by means of precocious corrective surgical intervention.

New Composite Index Based on Midlatency Auditory Evoked Potential and Electroencephalographic Parameters to Optimize Correlation with Propofol Effect Site Concentration

2005 ◽  
Vol 103 (3) ◽  
pp. 500-507 ◽  
Author(s):  
Hugo E. M. Vereecke ◽  
Pablo Martinez Vasquez ◽  
Erik Weber Jensen ◽  
Olivier Thas ◽  
Rudy Vandenbroecke ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Drug Effect ◽  
Composite Index ◽  
Auditory Evoked Potential ◽  
Anesthetic Drug ◽  
Potential Index ◽  
Prediction Probability ◽  
Effect Site Concentration

Background This study investigates the accuracy of a composite index, the A-Line(R) auditory evoked potentials index version 1.6 (AAI1.6; Danmeter A/S, Odense, Denmark), as a measure of cerebral anesthetic drug effect in a model for predicting a calculated effect site concentration of propofol (CePROP). The AAI1.6 algorithm extracts information from the midlatency auditory evoked potentials, the spontaneous electroencephalographic activity, and the detection of burst suppression. The former version of this monitor, the A-Line auditory evoked potential index version 1.5, is only based on fast extracted midlatency auditory evoked potential information. Methods After institutional ethics committee approval (University Hospital, Ghent, Belgium), informed consent was obtained from 13 patients (10 women, 3 men) with an American Society of Anesthesiologists physical status of I, aged 18-65 yr, who were scheduled to undergo ambulatory gynecologic or urologic surgery. The authors evaluated for Bispectral Index, A-Line auditory evoked potential index, version 1.5, AAI1.6 scaled from 0 to 100 and AAI1.6 scaled from 0 to 60, the interpatient stability at baseline, the detection of burst suppression, prediction probability, and correlation with CePROP, during a constant infusion of 1% propofol at 300 ml/h. The authors developed pharmacodynamic models relating the predicted CePROP to each measure of cerebral anesthetic drug effect. Results Bispectral Index had the lowest interindividual baseline variability. No significant difference was found with prediction probability analysis for all measures. Comparisons for correlation were performed for all indices. The AAI1.6 scaled to 60 had a significantly higher correlation with CePROP compared with all other measures. The AAI1.6 scaled to 100 had a significant higher correlation with CePROP compared with the A-Line auditory evoked potential index version 1.5 (P < 0.05) Conclusions The authors found that the application of AAI1.6 has a better correlation with a calculated CePROP compared with a solitary fast extracting midlatency auditory evoked potential measure. Whether this improvement in pharmacodynamic tracing is accompanied by an improved clinical performance should be investigated using clinical endpoints.

The Midlatency Auditory Evoked Potentials Predict Responsiveness to Verbal Commands in Patients Emerging from Anesthesia with Xenon, Isoflurane, and Sevoflurane but Not with Nitrous Oxide

2001 ◽  
Vol 94 (5) ◽  
pp. 782-789 ◽  
Author(s):  
Takahisa Goto ◽  
Yoshinori Nakata ◽  
Hayato Saito ◽  
Yoshiki Ishiguro ◽  
Yoshinari Niimi ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Spectral Power ◽  
High Energy ◽  
Auditory Evoked Potential ◽  
Verbal Command ◽  
First Response ◽  
Prominent Component ◽  
To Receive

Background It has recently been demonstrated that the approximately 40-Hz spectral power of the midlatency auditory evoked potential (MLAEP) correlates well with wakefulness during desflurane or propofol anesthesia. The aim of this study was to characterize how other inhalational anesthetics affects the MLAEP as the patients regain responsiveness to simple verbal command during emergence from anesthesia. Methods Sixty patients were randomly assigned to receive xenon, isoflurane, sevoflurane, or nitrous oxide (N2O) supplemented with epidural anesthesia. During emergence, the concentration of an anesthetic was decreased in 0.1-minimum alveolar concentration (MAC) decrements from 0.8 MAC or from 70% in the case of N2O, and each new concentration was maintained for 15 min. Every 5 min during each equilibration period, the MLAEP was recorded and the patients were asked to open their eyes and squeeze and release the investigator's hand. This process was repeated until the first response to either of these commands was observed. Results Thirteen patients were excluded because of technical reasons. The preanesthetic MLAEP showed a periodic waveform, where the Na-Pa-Nb complex was the most prominent component contributing to the high energy around 29-39 Hz in the power spectrum. Emergence from xenon, isoflurane, and sevoflurane anesthesia produced similar changes in the MLAEP. The spectral power for the frequency 29 Hz or greater was severely suppressed at 0.8 MAC but significantly recovered between the concentration only 0.1 MAC higher that permitting the first response to command and that associated with the first response. In contrast, N2O hardly affected the MLAEPs, even at the concentrations producing unresponsiveness. Two patients did not lose responsiveness even at the highest concentration tested (70%). Conclusions The MLAEP is closely associated with responsiveness to verbal command during emergence from anesthesia with xenon, isoflurane, and sevoflurane but not with N2O.

High-Frequency Hearing Losses Caused by Low-Frequency Noises

1978 ◽  
Vol 86 (5) ◽  
pp. ORL-821-ORL-823 ◽  
Author(s):  
John H. Mills ◽  
Warren Y. Adkins ◽  
Robert M. Gilbert
Keyword(s):  
High Frequency ◽  
Human Subjects ◽  
Low Frequency ◽  
Wave Pattern ◽  
Travelling Wave ◽  
Center Frequency ◽  
Octave Band ◽  
Distortion Products ◽  
Band Noise ◽  
Cochlear Partition

Human subjects were exposed to an octave-band noise for 24 hours. Temporary threshold shifts increased for the first eight hours of exposure and then were asymptotic. While threshold shifts were largest at about one-half octave above the center frequency of the noise, a second maximum was observed at higher test frequencies. The exact frequency of this second maximum decreased from 7.0 kHz, for a noise centered at 2.0 kHz, to 5.5 kHz for a noise centered at 0.5 kHz. This result could be caused by the travelling wave pattern along the cochlear partition or to the production of distortion products.

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