Objectives: Noise-induced cochlear synaptopathy is studied extensively in animal models. The diagnosis of synaptopathy in humans is challenging and the roles of many noninvasive measures in identifying synaptopathy are being explored. The acoustic middle ear muscle reflex (MEMR) can be considered as a vital tool since noise exposure affects the low-spontaneous rate fibers that play an important role in elicitation of MEMR. The present study aimed at measuring MEMR threshold and MEMR strength. Design: The study participants were divided into two groups. All the participants had normal-hearing thresholds. The control group consisted of 25 individuals with no occupational noise exposure whereas noise exposure group had 25 individuals who were exposed to occupational noise of 85 dBA for a minimum period of 1 year. MEMR threshold and strength was assessed for pure tones (500 Hz and 1000 Hz) and broadband noise. Results: The results showed that the MEMR threshold was similar in both the groups. MEMR strength was reduced in noise exposure group compared to control group. Conclusions: The results of the study suggest that MEMR strength could be used as a sensitive measure in identifying cochlear synaptopathy with careful consideration of the stimulus characteristics.

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Purpose: The objective of the current study was to describe outcomes on physiological and perceptual measures of auditory function in human listeners with and without a history of recreational firearm noise exposure related to hunting. Design: This study assessed the effects of hunting-related recreational firearm noise exposure on audiometric thresholds, oto-acoustic emissions (OAEs), brainstem neural representation of fundamental frequency (F0) in frequency following responses (FFRs), tonal middle-ear muscle reflex (MEMR) thresholds, and behavioral tests of auditory processing in 20 young adults with normal hearing sensitivity. Results: Performance on both physiological (FFR, MEMR) and perceptual (behavioral auditory processing tests) measures of auditory function were largely similar across participants, regardless of hunting-related recreational noise exposure. On both behavioral and neural measures including different listening conditions, performance degraded as difficulty of listening condition increased for both nonhunter and hunter participants. A right-ear advantage was observed in tests of dichotic listening for both nonhunter and hunter participants. Conclusion: The null results in the current study could reflect an absence of cochlear synaptopathy in the participating cohort, variability related to participant characteristics and/or test protocols, or an insensitivity of the selected physiological and behavioral auditory measures to noise-induced synaptopathy.

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Road traffic is the major source of noise pollution leading to human health impacts in urban areas. This study presents the relation between changes in human brain waves due to road traffic noise exposure in heterogeneous conditions. The results are based on Electroencephalogram (EEG) data collected from 12 participants through a listening experience of traffic scenarios at 14 locations in New Delhi, India. Energetic, spectral and temporal characteristics of the noise signals are presented. The impact of noise events on spectral perturbations and changes in the relative power (RP) of EEG signals are evaluated. Traffic noise variations modulate the rate of change in α and θ EEG bands of temporal, parietal and frontal lobe of the brain. The magnitude of event-related spectral perturbation (ERSP) increases with each instantaneous increase in traffic noise, such as honking. Individual noise events impact the temporal lobe more significantly in quieter locations compared with noisy locations. Increase in loudness changes the RP of α band in frontal lobe. Increase in temporal variation due to intermittent honking increases the RP of θ bands, especially in right parietal and frontal lobe. Change in sharpness leads to variation in the RP of right parietal lobe in theta band. Whereas, inverse relation is observed between roughness and the RP of right temporal lobe in gamma band. A statistical relationship between noise indicators and EEG response is established.

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Purpose: Exposure to noise has been related to aggressive behavior. As hospital noise may affect nursing students’ psycho-physiological health due to their inexperience, it ;1;is important to investigate possible violent tendencies among them. Since no similar research has been found in the literature, a study has been conducted to investigate the relationship between noise sensitivity and violence tendencies among nursing students. Methods: The design of this study was cross-sectional. There were 260 nursing students (61% female) aged 18 to 24 years who filled out the Personal Information Form, Weinstein’s Noise Sensitivity scale, and Violence Tendency scale. We investigated the distribution of students’ noise sensitivity and violence tendencies scores in relation to age, gender, grade, and place of residence. Multiple regression analysis was performed with the noise sensitivity score and possible confounders as independent variables and the severity tendency score as a dependent variable. Results: We found smoking to be significantly and positively associated with both noise sensitivity and violent tendencies (P < 0.001). Multiple regression analysis with smoking as a possible confounder revealed that a raise of 0.203 units on the violence tendencies scale may be expected per unit increase on the noise sensitivity scale (P < 0.001). Conclusion: Due to the limitations of our study, a possible relationship between nursing students’ noise sensitivity and violent tendencies is tentatively pointed out. More detailed studies are needed to test this assumption.

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Background: Due to the socio-cultural differences between China and other countries, which may affect the development of an individual’s personality and behavior, it is necessary to explore the relationship between personality traits and tinnitus distress in the context of China’s socio-cultural background. Methods: The Tinnitus Handicap Inventory and the Eysenck Personality Questionnaire Short Scale Chinese version were used to explore the influence of personality traits on tinnitus distress in Chinese patients with tinnitus. Results: The results were not entirely consistent with previous studies from other countries. First, extroversion was significantly higher in patients with bothersome tinnitus, both in acute and chronic conditions. Second, the personality traits that affected the patients with bothersome tinnitus were different in different conditions. Finally, the tridimensional personality structure, high psychoticism / normal extroversion / normal neuroticism, was significantly higher in people with bothersome tinnitus. Furthermore, the difference became more obvious with a prolonged disease course. Conclusions: This study suggested that the relationship between personality traits and tinnitus distress in Chinese patients with tinnitus was not the same as in other countries. “High psychoticism / normal extroversion / normal neuroticism” may be a risk factor for chronic bothersome tinnitus in China.

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