Recovery of thresholds and temporal integration in adult chickens after high‐level 525‐Hz pure‐tone exposure

1995 ◽  
Vol 97 (2) ◽  
pp. 1150-1164 ◽  
Author(s):  
Samuel S. Saunders ◽  
Richard J. Salvi ◽  
Karen M. Miller
Keyword(s):  
Pure Tone ◽  
Temporal Integration ◽  
High Level

Signal coding in cockroach photoreceptors is tuned to dim environments

2012 ◽  
Vol 108 (10) ◽  
pp. 2641-2652 ◽  
Author(s):  
K. Heimonen ◽  
E.-V. Immonen ◽  
R. V. Frolov ◽  
I. Salmela ◽  
M. Juusola ◽  
...  
Keyword(s):  
Information Transfer ◽  
Periplaneta Americana ◽  
Single Photon ◽  
Signal To Noise Ratio ◽  
Temporal Integration ◽  
High Sensitivity ◽  
Single Photons ◽  
Low Frequencies ◽  
Whole Cell Patch Clamp ◽  
High Level

In dim light, scarcity of photons typically leads to poor vision. Nonetheless, many animals show visually guided behavior with dim environments. We investigated the signaling properties of photoreceptors of the dark active cockroach ( Periplaneta americana) using intracellular and whole-cell patch-clamp recordings to determine whether they show selective functional adaptations to dark. Expectedly, dark-adapted photoreceptors generated large and slow responses to single photons. However, when light adapted, responses of both phototransduction and the nontransductive membrane to white noise (WN)-modulated stimuli remained slow with corner frequencies ∼20 Hz. This promotes temporal integration of light inputs and maintains high sensitivity of vision. Adaptive changes in dynamics were limited to dim conditions. Characteristically, both step and frequency responses stayed effectively unchanged for intensities >1,000 photons/s/photoreceptor. A signal-to-noise ratio (SNR) of the light responses was transiently higher at frequencies <5 Hz for ∼5 s after light onset but deteriorated to a lower value upon longer stimulation. Naturalistic light stimuli, as opposed to WN, evoked markedly larger responses with higher SNRs at low frequencies. This allowed realistic estimates of information transfer rates, which saturated at ∼100 bits/s at low-light intensities. We found, therefore, selective adaptations beneficial for vision in dim environments in cockroach photoreceptors: large amplitude of single-photon responses, constant high level of temporal integration of light inputs, saturation of response properties at low intensities, and only transiently efficient encoding of light contrasts. The results also suggest that the sources of the large functional variability among different photoreceptors reside mostly in phototransduction processes and not in the properties of the nontransductive membrane.

High-Level Psychophysical Tuning Curves

1991 ◽  
Vol 34 (2) ◽  
pp. 360-373 ◽  
Author(s):  
David A. Nelson ◽  
Todd W. Fortune
Keyword(s):  
Background Noise ◽  
Pure Tone ◽  
Narrow Band ◽  
Tuning Curve ◽  
Broad Band ◽  
Low Frequency ◽  
Tuning Curves ◽  
Tuning Characteristic ◽  
High Level ◽  
Combination Bands

Simultaneous-masked psychophysical tuning curves were obtained from normal-hearing listeners using low-level (20–25 dB SPL) probe tones in quiet and high-level (60 dB SPL) probe tones, both in quiet and in the presence of a broad-band background noise. The background noise was introduced to eliminate combination tones or combination bands and other off-frequency listening cues that exist at high levels. Tuning curves were obtained using pure-tone maskers and 100-Hz-wide narrow-band noise maskers for probe tones at 1000 and 4000 Hz. High-level tuning curves for pure-tone maskers demonstrated large discontinuities or “notches” on the low-frequency sides of the tuning curves. Broad-band background noise eliminated those notches, indicating that the notches were due to the detection of off-frequency listening cues at combination-tone frequencies. High-level tuning curves for 100-Hz-wide narrow-band maskers also demonstrated notches on the low-frequency sides. Those notches were eliminated with broad-band background noise, which indicates that combination bands strongly influenced the shapes of high-level tuning curves obtained with narrow-band maskers. The influence of combination bands was dependent upon test frequency. At 1000 Hz, combination bands had very little influence on the shapes of high-level tuning curves. At 4000 Hz, where the masker bandwidth was substantially less than the critical bandwidth, combination bands strongly affected the low-frequency sides of the tuning curves. In 2 subjects tested at a probe frequency of 2000 Hz with 100-Hz-wide masking bands, combination bands also influenced the lowfrequency sides of high-level tuning curves. The presence of combination-tone or combination-band cues essentially steepened the low-frequency slopes of tuning curves, resulting in sharper estimates of tuning. Comparisons of tuning curves obtained with pure-tone maskers and narrow-band maskers, in the same listeners, revealed that pure-tone maskers were more effective than narrow-band maskers when the masker frequencies were in the tail region of the tuning curve. The results of these experiments support the notion that tuning in the normal auditory system broadens notably with stimulus level, once off-frequency listening cues such as combination tones or combination bands are eliminated. The low-level simultaneously masked tuning curve demonstrates a sharp bandpass tuning characteristic, whereas the high-level simultaneously masked tuning curve in background noise demonstrates a broad low-pass tuning characteristic. It is argued that comparisons of tuning in impaired ears with tuning in normal ears should be made using estimates of tuning in normal ears that are not influenced by combination-tone or combination-band detection cues.

Cochlear Hair Cell and Vascular Changes in the Guinea Pig Following High Level Pure-Tone Exposures

1982 ◽  
Vol 94 (1-6) ◽  
pp. 403-411 ◽  
Author(s):  
D. Vertes ◽  
P. Nilsson ◽  
J. Wersall ◽  
A. Axelsson ◽  
B. Björkroth
Keyword(s):  
Guinea Pig ◽  
Hair Cell ◽  
Pure Tone ◽  
Vascular Changes ◽  
Cochlear Hair Cell ◽  
High Level

Pure-Tone Octave Masking in Normal-Hearing Listeners

1974 ◽  
Vol 17 (2) ◽  
pp. 223-251 ◽  
Author(s):  
David A. Nelson ◽  
Robert C. Bilger
Keyword(s):  
Temporal Pattern ◽  
Pure Tone ◽  
Pattern Discrimination ◽  
Signal Frequency ◽  
Physiological Data ◽  
Phase Effect ◽  
Low Frequencies ◽  
High Frequencies ◽  
High Level ◽  
Temporal Pattern Discrimination

Octave masking was investigated at four different frequencies (250, 500, 1000, and 2000 Hz) as a function of intensity of the masker and phase of the test signal. Slopes of phase-locked octave masking were found to increase with masking signal frequency, from 0.80 dB/dB at 250 Hz to 3.0 dB/dB at 2000 Hz. The monaural octave-masking phase effect was considerably larger for masking signals at low frequencies than at high frequencies, and the phase effect decreased or disappeared entirely for high-level masking signals. Interpretations are considered which take recent neurophysiological and physiological data into account, and which describe the octave-masking phase effects in terms of temporal pattern discrimination. Those interpretations adequately account for the frequency dependencies found in octave-masking phase effects.

Screening for Hearing Loss in Adolescents

1997 ◽  
Vol 28 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Alice E. Holmes ◽  
Holly S. Kaplan ◽  
Regina M. Phillips ◽  
F. Joseph Kemker ◽  
F. Thomas Weber ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Failure Rate ◽  
Educational Intervention ◽  
Pure Tone ◽  
Noise Exposure ◽  
Adolescent Population ◽  
Screening Protocol ◽  
High Level

Three-hundred-forty-two adolescents between the ages of 10–20 years were administered an auditory screening protocol consisting of a: (a) noise history questionnaire, (b) otoscopic inspection, (c) tympanometry, and (d) pure-tone screening at 25 dB HL at 1000, 2000, 4000, and 6000 Hz. Results of this screening protocol suggest a high level of admitted noise exposure in the adolescent population. Overall failure rate was 25%. Pure-tone failure rate was 7% for the frequencies of 1000, 2000, and 4000 Hz, increasing to 17% when 6000 Hz was added. Significant correlations were found between firearm use and hearing loss at 6000 Hz. Recommendations for screening the adolescent population are made, and suggestions for educational intervention on the effects of firearm usage are provided.

scholarly journals Subliminal temporal integration of linguistic information

2020 ◽  
Author(s):  
Shao-Min Hung ◽  
Po-Jang Hsieh
Keyword(s):  
Information Integration ◽  
Word Association ◽  
Temporal Integration ◽  
Separate Experiment ◽  
Decision Task ◽  
Interocular Suppression ◽  
Linguistic Information ◽  
Complex Information ◽  
High Level ◽  
Over Time

Whether unconscious complex information integration occurs over time remains largely unknown and highly controversial. To directly examine the possibility, we introduced a novel interocular suppression where the suppressor and suppressed are presented intermittently. Such paradigm allowed us to insert a word in each suppression and over time deliver sentence level information unconsciously. We found that subsequent to a subliminal context, participants responded faster to a syntactically incongruent target word in a lexical decision task. This finding was later replicated in a separate experiment where participants exhibited chance rate localization of the prime word. Such effect disappeared when the context was disrupted by presenting only partial sentence or with reversed word order, showing that the effect was not merely driven by word-word association. These findings indicate that linguistic information could integrate over time under interocular suppression, serving as critical evidence supporting unconscious high-level, complex information integration.

scholarly journals Temporal integration of high-level summary statistical representation

2010 ◽  
Vol 8 (6) ◽  
pp. 343-343
Author(s):  
T. Harp ◽  
J. Haberman ◽  
D. Whitney
Keyword(s):  
Temporal Integration ◽  
Statistical Representation ◽  
Summary Statistical Representation ◽  
High Level

scholarly journals Comparison between auditory steady-state responses and pure-tone audiometry

2010 ◽  
Vol 67 (9) ◽  
pp. 761-765 ◽  
Author(s):  
Zoran Komazec ◽  
Slobodanka Lemajic-Komazec ◽  
Rajko Jovic ◽  
Congor Nadj ◽  
Ljiljana Jovancevic ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Pure Tone ◽  
Hearing Threshold ◽  
Pure Tone Audiometry ◽  
Correlation Coefficients ◽  
Test Method ◽  
Complementary Method ◽  
Hearing Thresholds ◽  
High Level

Background/Aim. A more recent method, the auditory steadystate response (ASSR), has become more and more important test method due to difference that was found in previous investigations between hearing thresholds determined by the ASSR and the pure-tone audiometry (PTA). The aim of this study was to evaluate the reliability of the ASSR in determining the frequency specific hearing thresholds by establishing a correlation between the thresholds determined by PTA, as well as to evaluate the reliability of ASSR in determining the hearing threshold with respect to the level of hearing loss and the configuration of the PTA findings. Methods. The prospective study included 46 subjects (92 ears) which were assigned to groups based on their level of hearing loss and audiometric configuration. All the subjects underwent determination of hearing thresholds by PTA and ASSR without insight into their previously obtained PTA results. Results. The overall sample differences between the ASSR and PTA thresholds were 4.1, 2.5, 4.4, and 4.2 dB at 0.5, 1, 2, and 4 kHz, respectively. A high level of correlation was achieved in groups with different configurations of PTA findings. The correlation coefficients between the hearing thresholds determined by ASSR and PTA were significant in subjects with all levels of hearing loss. The differences between hearing thresholds determined by ASSR and PTA were less than 10 dB in 85% of subjects (ranging from 4 dB for moderately severe hearing loss to 7.2 dB for normal hearing). Conclusion. The ASSR is an excellent complementary method for the determination of hearing thresholds at the 4 carrier frequencies, as well as determination of the level of hearing loss and the audiometric configuration.

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