Auditory perceptual thresholds for sensitizers, defensive and nondefensive repressors.
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Aggression↗
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Results for “Auditory Threshold”
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[Study of the auditory discrimination threshold in a timed series of impulses].
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Auditory Perception↗
Psychophysiological characteristics of anxiety patients and controls.
87 patients with panic syndrome or agoraphobia with panic were compared with 28 generalized anxiety patients and 29 controls. Psychophysiological measures included rating scales, autonomic responses patterns, auditory thresholds and vigilance characteristics. In panic patients the state anxiety and the blood and injury phobia were significantly higher than in generalized anxiety patients. The generalized anxiety group could be characterized by high trait anxiety, suicidal ideation and lower capacity for sustained attention. Phasic electrodermal response amplitudes to the first verbal stimulus were significantly higher on the nondominant hands of the panic patients and on the dominant hands of the generalized anxiety patients. At 8,000 Hz panic and generalized anxiety patients showed opposite asymmetries of auditory thresholds with a left ear advantage for generalized anxiety patients and a right ear advantage for panic patients. These results suggest a relative left-hemispheric activation dominance in panic patients and a relative right-hemispheric dominance in generalized anxiety patients. The most consistent background factors in both anxiety groups were the highly significantly increased dysfunctional attitudes, first of all the high level of external control compared to controls.
Agoraphobia↗
Noise exposure induces up-regulation of ecto-nucleoside triphosphate diphosphohydrolases 1 and 2 in rat cochlea.
Extracellular ATP acting via P2 receptors in the inner ear initiates a variety of signaling pathways that may be involved in noise-induced cochlear injury. Nucleoside triphosphate diphosphohydrolase (NTPDase)1/CD39 and NTPDase2/CD39L1 are key elements for regulation of extracellular nucleotide concentrations and P2 receptor signaling in the cochlea. This study characterized the effect of noise exposure on regulation of NTPDase1 and NTPDase2 expression in the cochlea using a combination of real-time RT-PCR, immunohistochemistry and functional studies. Adult Wistar rats were exposed to broad band noise at 90 dB and 110 dB sound pressure level (SPL) for 72 h. Exposure to 90 dB SPL induced a small and temporary change of auditory thresholds (temporary threshold shift), while exposure to 110 dB SPL induced a robust and permanent change of auditory thresholds (permanent threshold shift). NTPDase1 and NTPDase2 mRNA transcripts were upregulated in the cochlea exposed to 110 dB SPL, while mild noise (90 dB SPL) altered only NTPDase1 mRNA expression levels. Changes in NTPDases expression did not correlate with levels of circulating corticosterone, implying that the up-regulation of NTPDases expression was not stress-related. Semi-quantitative immunohistochemistry in the cochlea exposed to 110 dB SPL localized the increased NTPDase1 and NTPDase2 immunostaining in the stria vascularis and up-regulation of NTPDase2 in the intraganglionic spiral bundle. In contrast, NTPDase1 was down-regulated in the cell bodies of the spiral ganglion neurones. Distribution of NTPDases was not altered in the cochlea exposed to 90 dB SPL. Functional studies revealed increased ectonucleotidase activities in the cochlea after exposure to 110 dB SPL, consistent with up-regulation of NTPDases. The changes in NTPDases expression may reflect adaptive response of cochlear tissues to limit ATP signaling during noise exposure.
Acoustic Stimulation↗
[Study on the correlation of substance P in middle ear effusion and clinical presentation in secretory otitis media].
OBJECTIVE: To investigate the correlation of substance P in middle ear effusion and clinical presentation in secretory otitis media. METHOD: Observation on relation between clinical presentation (the course of disease, the hearing loss, quantity of middle ear effusion or quality) and substance P (SP) content of middle ear effusion (MEE) in 64 cases (79 ears) of secretory otitis media (SOM). RESULT: SP concentration of MEE in serous group was remarkably higher than that in the mucous group (P < 0.01). SP concentration of MEE had positive correlation with the volume (r = 0.985, P < 0.01), and negative correlation with the course of disease (r = -0.6217, P < 0.01). The hearing loss of mucous group was remarkably higher than that of the serous group (P < 0.01). SP concentration of MEE in serous group had positive correlation with auditory threshold (r = 0.9553, P < 0.01). SP concentration of MEE in mucous had no correlation with auditory threshold. CONCLUSION: SP might play an important role in SOM. The detection of SP content in MEE is of important significance for judging quality of MEE and understanding the course of disease.
Adolescent↗
Comparison of auditory steady-state response and auditory brainstem response thresholds in children.
Recently, auditory steady-state responses (ASSRs) have been proposed as an alternative to the auditory brainstem response (ABR) for threshold estimation. The goal of this study was to investigate the degree to which ASSR thresholds correlate with ABR thresholds for a group of sedated children with a range of hearing losses. Thirty-two children from the University of Iowa Hospitals and Clinics ranging in age from 2 months to 3 years and presenting with a range of ABR thresholds participated. Strong correlations were found between the 2000-Hz ASSR thresholds and click ABR thresholds (r = .96), the average of the 2000- and 4000-Hz ASSR thresholds and click ABR thresholds (r = .97), and the 500-Hz ASSR and 500-Hz toneburst ABR thresholds (r = .86). Additionally, it was possible to measure ASSR thresholds for several children with hearing loss that was great enough to result in no ABR at the limits of the equipment. The results of this study indicate that the ASSR may provide a reasonable alternative to the ABR for estimating audiometric thresholds in very young children.
Auditory Perception↗
Auditory awakening thresholds and dream recall in NREM sleep.
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Adolescent↗
Hearing loss in children with type 1 diabetes.
OBJECTIVE: To examine the auditory function in a group of children with type 1 diabetes, and to study the association between hearing impairment and duration of illness, metabolic control and diabetic complication. METHODS: Sixty-three diabetic patients below the age of 18 attending the university hospital in Khartoum, Sudan were investigated together with 63 age and sex matched non-diabetic controls. Pure-tone audiometric tests were performed using an Amplaid 300 clinical audiometer in a soundproof room. Both air and bone conduction were tested at frequencies between 250-8000 Hz and 250-4000 Hz respectively. Hearing impairment was noted at auditory threshold above 25 dB in any frequency and the magnitude of hearing loss was assessed according to auditory threshold in conversational frequencies only. RESULTS: The hearing acuity was lower in the diabetic patients than in the control subjects in all tested frequencies, but the differences achieve statistical significance only at middle and high frequencies. The hearing loss was symmetrical, generally mild, and affects both sexes equally. Duration of diabetes, HbA1c concentration, and angiopathic complications showed positive correlation with the increased hearing thresholds; while, age at onset, insulin dose per day, presence of neuropathy, and frequency of DKA and hypoglycaemic episodes were not associated. CONCLUSION: Hearing loss occurs early in diabetic children and is related to the duration of the disease and the degree of metabolic control. Strict glycemic control might prevent or delay this complication.
Adolescent↗
The mechanism of hearing loss in Paget's disease of bone.
OBJECTIVES/HYPOTHESIS: The mechanism of hearing loss (HL) in Paget's disease of bone was investigated. The present study was a systematic, prospective, controlled set of clinical investigations to test the hypothesis that there is a general underlying mechanism of HL in Paget's disease of bone and to gain additional insights into the auditory and otologic dynamics of this disease. Specific questions were 1) whether the mechanism is cochlear or retrocochlear and 2) whether the bone mineral density of the cochlear capsule is related to hearing levels. STUDY DESIGN: Several double-blinded, cross-sectional, prospective, correlational studies were conducted in a population of elderly human subjects with skull involvement with Paget's disease versus a control population of elderly subjects free of Paget's disease. Demographic and clinical data were recorded. Longitudinal observations were made in subjects under treatment. METHODS: Subjects were recruited from a Paget's disease clinic. Pure-tone auditory thresholds, word recognition, and auditory brainstem responses (ABRs) were recorded. The dimensions of the internal auditory canals were measured using computed tomographic (CT) images and digital image analysis. The precision, accuracy, and temporal stability of methods to measure the bone mineral density of the cochlear capsule and an adjacent area of nonotic capsule bone were validated and applied. Correlations were sought between hearing levels and cochlear capsule bone mineral density. RESULTS: ABRs were recorded in 64 ears with radiographically confirmed Paget's disease involving the skull. Responses were absent in eight ears, all of which had elevated high pure-tone thresholds. ABRs were interpreted as normal in 56 ears; none were abnormal. The mid-length diameter and minimum diameter of the internal auditory canal of 68 temporal bones from subjects with Paget's disease were found to have no statistically significant relationship to hearing thresholds. The Pearson product-moment correlation coefficients (age- and sex-adjusted) in the group with Paget's disease involving the temporal bone were -0.63 for left ears and -0.73 for right ears for high-frequency air conduction pure-tone thresholds (mean of 1, 2, and 4 kHz) versus cochlear capsule density. Correlation coefficients (age- and sex-adjusted) between cochlear capsule density and air-bone gap (mean at 0.5 and 1 kHz) for the affected group were -0.67 for left ears and -0.63 for right ears. All correlations between hearing thresholds and cochlear capsule density in pagetic subjects were significant at P <.001. The regressions were consistent throughout the ranges of hearing level. There were no significant correlations between cochlear capsule mean density and hearing level in the volunteer subjects. CONCLUSIONS: The evidence supports the existence of a general, underlying, cochlear mechanism of pagetic HL that is closely related to loss of bone mineral density in the cochlear capsule. This mechanism accounts well for both the high-frequency sensorineural HL and the air-bone gap. Early identification, radiographic diagnosis of temporal bone involvement, and vigorous treatment with third-generation bisphosponates are important to limit the development and progression of pagetic HL.
Adult↗
Evaluation of inner ear damage during conditions with middle ear effusion by use of brainstem audiometry.
The method of auditory evoked brainstem responses (AEBR) was applied on an animal model with two types of well defined middle ear effusions--serous otitis media (SOM) and purulent otitis media (POM). The animals with SOM exhibited fairly normal interpeak latencies but a considerably increased auditory threshold. In contrast, POM mainly affected the latencies of the brainstem evoked potential but also caused a slight increase of the auditory threshold. The results indicate that SOM chiefly causes a conductive hearing loss, while POM also affects the neural circuit.
Animals↗
Relationships between middle latency auditory responses (MLR) and speech discrimination tests in the elderly.
74 subjects aged between 60 and 80 years underwent tonal audiometry, speech discrimination tests (phonetically balanced words, normal sentences and compressed sentences) and middle latency responses (MLRs) in order to evaluate possible correlations between behavioural and electrophysiological tests. The results showed that in elderly patients normal sentences are better understood than phonetically balanced words, that performances decrease dramatically when listening conditions became difficult, that auditory threshold seems to influence speech discrimination scores more than does age per se. MLRs seem to be unaffected both by age and by auditory threshold and Pa occurrence is a more reliable parameter than its latency. No correlation between speech discrimination tests and MLRs could be observed; on the contrary in the presence of abnormal speech discrimination tests the MLRs were almost normal and vice versa.
Aged↗
Predicting the threshold of pulse-train electrical stimuli using a stochastic auditory nerve model: the effects of stimulus noise.
The incorporation of low levels of noise into an electrical stimulus has been shown to improve auditory thresholds in some human subjects (Zeng et al., 2000). In this paper, thresholds for noise-modulated pulse-train stimuli are predicted utilizing a stochastic neural-behavioral model of ensemble fiber responses to bi-phasic stimuli. The neural refractory effect is described using a Markov model for a noise-free pulse-train stimulus and a closed-form solution for the steady-state neural response is provided. For noise-modulated pulse-train stimuli, a recursive method using the conditional probability is utilized to track the neural responses to each successive pulse. A neural spike count rule has been presented for both threshold and intensity discrimination under the assumption that auditory perception occurs via integration over a relatively long time period (Bruce et al., 1999). An alternative approach originates from the hypothesis of the multilook model (Viemeister and Wakefield, 1991), which argues that auditory perception is based on several shorter time integrations and may suggest an NofM model for prediction of pulse-train threshold. This motivates analyzing the neural response to each individual pulse within a pulse train, which is considered to be the brief look. A logarithmic rule is hypothesized for pulse-train threshold. Predictions from the multilook model are shown to match trends in psychophysical data for noise-free stimuli that are not always matched by the long-time integration rule. Theoretical predictions indicate that threshold decreases as noise variance increases. Theoretical models of the neural response to pulse-train stimuli not only reduce calculational overhead but also facilitate utilization of signal detection theory and are easily extended to multichannel psychophysical tasks.
Algorithms↗
Distortion product otoacoustic emissions and sensorineural hearing loss.
As other types of otoacoustic emissions, distortion product otoacoustic emissions (DPOAEs) allow the exploration of the active cochlear mechanisms known to take place in the outer hair cell system. Most authors consider that 2f1-f2 DPOAEs are generated in a cochlear region corresponding to the geometric mean (GM) of the primary frequencies. To verify the relevance of this hypothesis in clinical practice, DPOAEs were recorded at seven different frequencies, ranging from 0.5 to 4 kHz, in 81 hearing-impaired patients and in 24 normally hearing subjects. To test the hypothesis that DPOAEs reflect the hearing threshold at the frequency of the GM rather than at the 2f1-f2 frequency, this study compares the 2f1-f2 frequency and the GM of the primaries to the frequency of hearing loss. DPOAEs can be used to explore a large range of frequencies, especially at high frequencies, but responses at low frequencies are less reliable due to noise contamination. Secondly, DPOAEs can be recorded in ears that have a hearing threshold as high as 65 dB HL at the frequency corresponding to the GM of the primaries. Finally, DPOAE recordings show frequency specificity: i.e., hearing loss at a specific frequency correlates best with DPOAEs whose GM of primary frequencies corresponds to the frequency of the hearing loss. However, this frequency specificity is still unsatisfactory and decreases as the levels of primaries increase above 60 dB SPL. Moreover, DPOAE amplitude is too variable to predict hearing loss at a particular frequency, whereas DPOAE threshold allows a correct prediction of abnormal auditory threshold in more than 80% of the cases at frequencies above 1 kHz.
Acoustic Impedance Tests↗
Relative efficacy and toxicity of netilmicin and tobramycin in oncology patients.
We prospectively compared the efficacy and safety of netilmicin sulfate or tobramycin sulfate in conjunction with piperacillin sodium in 118 immunocompromised patients with presumed severe infections. The two treatment regimens were equally efficacious. Nephrotoxicity occurred in a similar proportion in patients treated with netilmicin and tobramycin (17% vs 11%). Ototoxicity occurred in four (9.5%) of 42 netilmicin and piperacillin and in 12 (22%) of 54 tobramycin and piperacillin-treated patients. Of those evaluated with posttherapy audiograms, three of four netilmicin and piperacillin-treated patients had auditory thresholds return to baseline compared with one of nine tobramycin and piperacillin-treated patients. The number of greater than or equal to 15-dB increases in auditory threshold as a proportion of total greater than or equal to 15-dB changes (increases and decreases) was significantly lower in netilmicin and piperacillin- vs tobramycin and piperacillin-treated patients (18 of 78 vs 67 of 115). We conclude that aminoglycoside-associated ototoxicity was less severe and more often reversible with netilmicin than with tobramycin.
Adult↗
Effects of alcohol and noise on temporary threshold shift in Guinea pigs.
The purpose of this study was to investigate the effects of concomitant exposure to noise and alcohol on the auditory thresholds. Twenty-four guinea pigs were equally divided into three groups: the acute intoxication group, the chronic intoxication group and the control group. Animals in the acute group received single intraperitoneal injections of ethanol (2 g/kg). In the chronic group, alcohol was administered via drinking water (10%, v/v) over a 60-day period. All animals were exposed to a white noise at the intensity of 105 dB A for 30 min. Auditory brainstem response (ABR) thresholds and distortion product otoacoustic emission (DPOAE) levels were measured before, immediately after noise exposure and also 1, 2, and 7 days following exposure. The results showed: first, acute alcohol injection caused a significant, temporary elevation of ABR threshold (4.8 dB in average), while chronic alcohol treatment did not change auditory threshold significantly. Second, noise exposure induced a mean threshold shift of 15.4- 19.7 dB. ABR threshold returned to normal 2 days after exposure. Both acute and chronic alcohol treatment did not alter the magnitude and time course of recovery of the temporary threshold shift (TTS). Third, the mean DPOAE amplitudes decreased at most frequencies following acute injection of alcohol. However, the differences did not reach statistical significance. Fourth, the mean DPOAE levels dropped 3.4-9.6 dB in all groups after noise exposure and returned to normal 1 day to 2 days after noise. There were no significant differences in the amount of DPOAE suppression after noise between the three groups. In summary, we have found that acute and chronic treatment of alcohol in combination with noise did not significantly exacerbate TTS or decrease DPOAE amplitudes relative to noise exposure alone.
Alcoholic Intoxication↗
Fluctuating sensorineural hearing loss in children.
Childhood sensorineural hearing loss (SNHL) that fluctuates or is progressive enhances parental concern and complicates medical management, hearing aid selection, and individualized educational planning for the affected child. Despite intensive multidisciplinary evaluation and intervention, continued threshold fluctuation or a gradual decline in auditory acuity may proceed unabated in a significant percentage of these youngsters. With the adoption of universal newborn hearing screening mandates by an increasing number of states, any challenges to the accurate determination of auditory thresholds must be addressed within the first few months of life.
Auditory Threshold↗
The effects of pentobarbital upon auditory and visual thresholds in the baboon.
Adult male baboons were trained to perform a reaction time procedure, which required holding a lever depressed for varying time intervals and releasing it during a 1.5 sec test stimulus to receive food. The test stimulus was a 16 kHz tone for auditory threshold testing, and a white light for visual threshold testing. Stimulus intensities were randomly varied to determine detection thresholds, and the latency of each correct lever release was recorded as a measure of reaction time. Acute, IM injections of pentobarbital (1.0 to 17.0 mg/kg) were given at the beginning of 2-hr experimental sessions. Pentobarbital elevated the absolute visual threshold and increased both auditory and visual reaction times in a dose-related manner. Two of three baboons showed reaction time and visual threshold decrements at pentobarbital doses which produced no change in absolute auditory thresholds.
Animals↗
Anatomical and functional recovery of the goldfish (Carassius auratus) ear following noise exposure.
Fishes can regenerate lateral line and inner ear sensory hair cells that have been lost following exposure to ototoxic antibiotics. However, regenerative capabilities following noise exposure have not been explored in fish. Moreover, nothing is known about the functional relationship between hair cell damage and hearing loss, or the time course of morphological versus functional recovery in fishes. This study examines the relationship between hair cell damage and physiological changes in auditory responses following noise exposure in the goldfish (Carassius auratus). Goldfish were exposed to white noise (170 dB re. 1 muPa RMS) for 48 h and monitored for 8 days after exposure. Auditory thresholds were determined using the auditory evoked potential technique, and morphological hair cell damage was analyzed using phalloidin and DAPI labeling to visualize hair cell bundles and nuclei. A TUNEL assay was used to identify apoptotic cells. Following noise exposure, goldfish exhibited a significant temporary threshold shift (TTS; ranging from 13 to 20 dB) at all frequencies tested (from 0.2-2 kHz). By 7 days post-exposure, goldfish hearing recovered significantly (mean TTS<4 dB). Increased apoptotic activity was observed in the saccules and lagenae between 0 and 2 days post-exposure. Immediately after noise exposure, the central and caudal regions of saccules exhibited significant loss of hair bundles. Hair bundle density in the central saccule recovered by the end of the experiment (8 days post-exposure) while bundle density in the caudal saccule did not return to control levels in this time frame. These data demonstrate that goldfish inner ear epithelia show damage following noise exposure and that they are capable of significant regenerative responses similar to those seen following ototoxic drug treatment. Interestingly, functional recovery preceded morphological recovery in the goldfish saccule, suggesting that only a subset of hair cells are necessary for normal auditory responses, at least to the extent that hearing was measured in this study.
Animals↗