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Hearing Research May 1998The purpose of the present study was to measure the change in threshold as a function of stimulus duration in single auditory nerve fibers. Thresholds were measured at... (Comparative Study)
Comparative Study
The purpose of the present study was to measure the change in threshold as a function of stimulus duration in single auditory nerve fibers. Thresholds were measured at each neuron's characteristic frequency (CF) for eight stimulus durations ranging from 8 to 1024 ms. Using an adaptive, two-interval, forced-choice threshold-tracking procedure with a 2-down, 1-up rule, thresholds were estimated based on a decision criterion of one spike or greater difference between tone and no-tone intervals. The results showed that mean thresholds decreased with increasing stimulus duration by approximately 14.6 dB over the range of durations tested. Analysis of group and individual data showed that thresholds decreased by approximately 6-7 dB per decade of duration. The slope of threshold improvement decreased systematically with increasing CF, consistent with previous physiological and psychophysical data.
Topics: Acoustic Stimulation; Animals; Auditory Threshold; Chinchilla; Evoked Potentials, Auditory, Brain Stem; Nerve Fibers; Vestibulocochlear Nerve
PubMed: 9641326
DOI: 10.1016/s0378-5955(98)00035-5 -
Hearing Research Mar 1981Perfusions of scala tympani with high potassium solutions increase spontaneous activity of auditory nerve fibres without affecting their threshold sensitivity. In these...
Perfusions of scala tympani with high potassium solutions increase spontaneous activity of auditory nerve fibres without affecting their threshold sensitivity. In these circumstances, however, the signal-to-noise ratio of the auditory nerve response to a given stimuli is worsened. Recordings from cochlear nucleus neurones during such perfusions indicate that this worsening is critical for threshold sensitivity at higher levels in the auditory pathway.
Topics: Acoustic Stimulation; Animals; Auditory Pathways; Auditory Threshold; Cochlear Nerve; Guinea Pigs; Nerve Fibers; Perfusion; Potassium; Scala Tympani; Vestibulocochlear Nerve
PubMed: 7204257
DOI: 10.1016/0378-5955(81)90039-3 -
Hearing Research Sep 1991A derived response method of acquiring frequency specific auditory evoked potentials that utilizes a pure tone in combination with a toneburst is applied to the... (Comparative Study)
Comparative Study
A derived response method of acquiring frequency specific auditory evoked potentials that utilizes a pure tone in combination with a toneburst is applied to the measurement of hearing sensitivity in guinea pigs, chinchillas and pocket gophers. Two experiments which demonstrate that thresholds acquired via tone-derived responses are 10 to 15 dB more sensitive than thresholds to solitary tonebursts are described. The derived potentials approximate behaviorally acquired thresholds at frequencies of 0.5 kHz and above. This technique may provide a more rapid means of assessing hearing sensitivity in laboratory animals than by behavioral means.
Topics: Acoustic Stimulation; Animals; Auditory Threshold; Behavior, Animal; Chinchilla; Evoked Potentials, Auditory, Brain Stem; Female; Guinea Pigs; Male; Rodentia
PubMed: 1752790
DOI: 10.1016/0378-5955(91)90097-s -
Lowering of an auditory threshold produced by a light signal occurring after the threshold stimulus.Nature Oct 1958
Topics: Auditory Threshold; Hearing
PubMed: 13590235
DOI: 10.1038/1821093a0 -
Audiology & Neuro-otology 2006In an experimental study, we determined the physiological hearing threshold of the rabbit in order to use these data as normative values for further experimental...
In an experimental study, we determined the physiological hearing threshold of the rabbit in order to use these data as normative values for further experimental investigations. The aim was to use different acoustic stimuli (click and tone-pip stimuli) with different frequency spectra for air and bone conduction (BC) in order to obtain further information about the optimal form of stimulus when recording auditory evoked potentials in the rabbit. For the investigation, we used 46 female New Zealand rabbits weighing 3.2-4.4 kg and aged 6 months. The equipment used to record brainstem auditory evoked potentials was the Nicolet Viking IV P System (Nicolet Biomedical, Inc.). In accordance with the experimental set-up, the measurements took place under intubation anesthesia, with a total of four repeat measurements performed on each ear at different times. Tone-pip and click stimuli with varying intensities of stimulus, transmitted via air conduction and BC, were applied. The I-IV waves proved the most stable for both stimulus modalities. They were registrable in 98.7% of cases, whereas only 30.2% of the V waves could be recorded. Values averaged from all measurements made throughout the study yielded a potential threshold of 34.8 dB peak equivalent (p.e.) SPL for the click stimulus, 13.8 dB p.e. SPL for the tone-pip stimulus at 8 kHz and 34.2 dB p.e. SPL for the click stimulus transmitted via BC. With regard to latencies, the results indicated a good reproducibility through different stimuli with acceptable standard deviations. The values for physiological hearing threshold obtained here can serve as normative data in subsequent experimental animal studies.
Topics: Acoustic Stimulation; Animals; Auditory Threshold; Evoked Potentials, Auditory, Brain Stem; Female; Rabbits; Reaction Time
PubMed: 16847386
DOI: 10.1159/000094601 -
Annual International Conference of the... Jul 2023The behavioural nature of pure-tone audiometry (PTA) limits those who can participate in the test, and therefore those who can access accurate hearing threshold...
The behavioural nature of pure-tone audiometry (PTA) limits those who can participate in the test, and therefore those who can access accurate hearing threshold measurements. Event Related Potentials (ERPs) from brain signals has shown limited utility on adult subjects, and a neural response that can consistently be identified as a result of pure-tone auditory stimulus has yet to be identified. The in doing so challenge is worsened by the nature of PTA, where stimulus amplitude decrease to a patient's lower threshold of hearing. We investigate whether EEGNet, a compact Convolutional Neural Network, could help in this domain. We trained EEGNet on a dataset collected whilst patients underwent a test designed to mimic a pure-tone audiogram, then assessed EEGNet performance in the detection task. For comparison, we also trained Support Vector Machines (SVMs) and Common Spatial Patterns + Linear Discriminant Analysis (CSPLDA) on the same task, with the same training paradigms. The results show that EEGNet is capable of detecting hearing events with 81.5% accuracy on unseen participants, outperforming SVMs by just over 5%. Whilst EEGNet outperformed SVMs and CSPLDA, it did not, however, always show a statistically significant improvement. Further analysis of EEGNet predictions revealed that, with sufficient test repetition, EEGNet has the potential to accurately ascertain hearing thresholds. The implication of these results is for a brain-signal based hearing test for those with physical or mental disabilities that limit their participation in a PTA. While this research is promising, future research will be needed to address the complexity of test setup, the duration of testing, and to further improve accuracy.
Topics: Adult; Humans; Auditory Threshold; Neural Networks, Computer; Audiometry, Pure-Tone; Hearing
PubMed: 38082774
DOI: 10.1109/EMBC40787.2023.10340112 -
Scientific Reports Jun 2016A natural auditory scene often contains sound moving at varying velocities. Using a velocity contrast paradigm, we compared sensitivity to velocity changes between...
A natural auditory scene often contains sound moving at varying velocities. Using a velocity contrast paradigm, we compared sensitivity to velocity changes between continuous and discontinuous trajectories. Subjects compared the velocities of two stimulus intervals that moved along a single trajectory, with and without a 1 second inter stimulus interval (ISI). We found thresholds were threefold larger for velocity increases in the instantaneous velocity change condition, as compared to instantaneous velocity decreases or thresholds for the delayed velocity transition condition. This result cannot be explained by the current static "snapshot" model of auditory motion perception and suggest a continuous process where the percept of velocity is influenced by previous history of stimulation.
Topics: Acoustic Stimulation; Adult; Auditory Threshold; Female; Humans; Male; Motion Perception; Sound; Sound Localization; Young Adult
PubMed: 27291488
DOI: 10.1038/srep27725 -
The Journal of the Acoustical Society... Jan 1987Auditory brain stem responses (ABRs) were recorded from ten normal-hearing subjects in response to 100-microseconds clicks from a TDH 49 earphone at a rate of 48 pps and...
Auditory brain stem responses (ABRs) were recorded from ten normal-hearing subjects in response to 100-microseconds clicks from a TDH 49 earphone at a rate of 48 pps and at levels randomly varied in 2-dB steps between 34 and 52 dB p.e. SPL. At each level, 10 000 epochs were averaged with use of a weighted concept and a running estimate was made of the signal-to-noise ratio (SNR). This quantity was used to detect the presence of the ABR and the median threshold was found at 38 dB p.e. SPL. The mean averaged background noise level was 11.3 nVrms, and the "true" ABRrms amplitude function crossed this value at 35.5 dB p.e. SPL, which indicates the level where the SNR = 1. By extrapolation, it was found that the ABR amplitude became zero at 32 dB p.e. SPL. The perceptual thresholds of the click were estimated by means of a modified block up-down procedure, and the median value was found at 33 dB p.e. SPL. The slope of the amplitude function and the magnitude of the averaged background noise are the two factors responsible for the ABR threshold sensitivity, which thus depends on both physiological and technical parameters. Therefore, these have to be considered together with the method of detection when the ABR is used to indicate the hearing sensitivity.
Topics: Auditory Threshold; Brain Stem; Evoked Potentials, Auditory; Humans; Psychoacoustics
PubMed: 3819168
DOI: 10.1121/1.395019 -
Brazilian Journal of Otorhinolaryngology 2015One of the problems observed in pure-tone audiometry tonal has been the variation in test results of a same individual, particularly at frequencies of 4kHz, 6kHz and/or... (Comparative Study)
Comparative Study
INTRODUCTION
One of the problems observed in pure-tone audiometry tonal has been the variation in test results of a same individual, particularly at frequencies of 4kHz, 6kHz and/or 8kHz. Improper placement of headphones is one of the factors that can cause alterations in results.
OBJECTIVE
To compare differences in auditory thresholds using earphones positioned by the examiner and by the worker.
METHODS
Clinical and experimental study conducted in 2009, with 324 workers aged between 19 and 61 years, with a mean of 33.29 years and mean exposure time of 7.67 years. All subjects were familiar with audiometry procedures. Auditory thresholds were obtained at frequencies of 0.25-8kHz, with earphones positioned by the examiners, and at frequencies of 4, 6 and 8kHz, with earphones placed by workers in a comfortable position, following the examiner's instructions. The thresholds obtained in these two situations were compared.
RESULTS
The three frequencies exhibited better responses with earphones placed by the workers themselves (p<0.001). At a frequency of 8kHz a greater difference was found (p<0.001), with a mean of 13.89dB and standard deviation of 6.07dB.
CONCLUSION
Earphone placement by the workers themselves under supervision of the examiner results in improved mean auditory thresholds at frequencies of 4, 6 and 8kHz, the last one significantly higher than the other two.
Topics: Adult; Audiometry, Pure-Tone; Auditory Perception; Auditory Threshold; Brazil; Female; Humans; Male; Middle Aged; Occupational Diseases; Occupational Health
PubMed: 26454532
DOI: 10.1016/j.bjorl.2015.08.016 -
Acta Oto-laryngologica 2015These findings suggest that Atrial natriuretic peptide (ANP) exhibits an inhibitory effect on auditory brainstem response (ABR) and is involved in the neuromodulation of...
CONCLUSION
These findings suggest that Atrial natriuretic peptide (ANP) exhibits an inhibitory effect on auditory brainstem response (ABR) and is involved in the neuromodulation of the auditory nervous system.
OBJECTIVES
ANP may alter electrophysiological properties of the cochlea and play a role in auditory action.
METHODS
This study was undertaken to examine and clarify the role of ANP in the rat auditory system using ABR audiometry. The mean ABR thresholds and the latencies for wave II at the ABR threshold altered at given frequencies throughout the study.
RESULTS
Intra-arterial infusion of ANP (0.1 mg/kg, 4 mg/kg, and 8 mg/kg; bolus injection) resulted in a significant increase in ABR thresholds. A significant shift in the ABR wave II latency was observed at lower frequency (1 kHz and 2 kHz). There was a little change in latency at 20 kHz. Increased amount of ANP significantly altered the ABR in rats.
Topics: Acoustic Stimulation; Animals; Atrial Natriuretic Factor; Audiometry, Pure-Tone; Auditory Threshold; Cochlea; Dose-Response Relationship, Drug; Evoked Potentials, Auditory, Brain Stem; Infusions, Intra-Arterial; Male; Rats; Rats, Sprague-Dawley
PubMed: 26245816
DOI: 10.3109/00016489.2015.1073354