Effects Of Loud Noise Research Articles

Editorial: Decision-making under stress: the importance of cortico-limbic circuits

Editorial: Decision-making under stress: the importance of cortico-limbic circuits

LoudNoise Exposure during Activity and Neurogenesis in the Living Rat Brain: Preliminary Study

Objective: The effects of loud noise (80 dB) on neurogenesis in the sub-ventricular zone (SVZ) and the hippocampal sub-granular zone (SGZ) was investigated in vivo in the rat brain using positron emission tomography (PET) with 3’-deoxy-3’- [18F]fluoro-L-thymidine ( [18F]FLT), a marker for thymidine kinase I (TK-1) related to cell proliferation and for neurogenesis in SVZ and SGZ. Methods: Five young Sprague-Dawley rats were exposed to loud noise from two speakers set in front of their cages during the night for 4 nights, and 5 control rats were exposed to normal quiet conditions. PET was performed 4 days after the exposure. Results: The accumulation of [18F] FLT in SVZ was significantly lower in the rats with noise exposure than in the control rats. The level of [18F] FLT uptake was lower in the SVZ than in the SGZ. Conclusion: Our results indicate that loud noise exposure during the awake period may be related to the decrease in proliferative capacity of neural stem cells especially in the SVZ of the living rat brain. This finding may indicate that persistent loud noise during daily life is harmful to brain development in humans

Targeting of the Adenosine Receptors as A Novel Strategy for the Treatment of Arterial Hypertension

Objective: The effects of loud noise (80 dB) on neurogenesis in the sub-ventricular zone (SVZ) and the hippocampal sub-granular zone (SGZ) was investigated in vivo in the rat brain using positron emission tomography (PET) with 3’-deoxy-3’- [18F]fluoro-L-thymidine ( [18F]FLT), a marker for thymidine kinase I (TK-1) related to cell proliferation and for neurogenesis in SVZ and SGZ. Methods: Five young Sprague-Dawley rats were exposed to loud noise from two speakers set in front of their cages during the night for 4 nights, and 5 control rats were exposed to normal quiet conditions. PET was performed 4 days after the exposure. Results: The accumulation of [18F] FLT in SVZ was significantly lower in the rats with noise exposure than in the control rats. The level of [18F] FLT uptake was lower in the SVZ than in the SGZ. Conclusion: Our results indicate that loud noise exposure during the awake period may be related to the decrease in proliferative capacity of neural stem cells especially in the SVZ of the living rat brain. This finding may indicate that persistent loud noise during daily life is harmful to brain development in humans.

Effects of loud noise on hippocampal and cerebellar-related behaviors.: Role of oxidative state

Living organisms are exposed to potentially hazardous noise levels coming from the environment. Besides the direct effect on hearing, extra-auditory noise-associated effects should be considered. Since loud noise has been suggested to induce central nervous system symptoms, the aim of the present work was to investigate the effect of acute (ANE) and chronic noise exposures (CNE) on different behavioral tasks. To understand the mechanisms involved, levels of oxidative status markers were determined in two areas related to memory processes, the hippocampus (Hip) and the cerebellum (CE). 15-day-old male Wistar rats were exposed to loud noise (95–97 dB, 2 h/day), at ANE or CNE. At 30 days, rats were subjected to different CE and Hip-related behavioral tasks. Reactive oxygen species (ROS) levels and antioxidant enzyme activities (CAT and SOD) were also assessed. Results show impairments in spatial and associative memory in noise-exposed animals. Moreover, a decrease in anxiety levels and an increase in habituation memory were observed in CNE animals. While an increase in cerebellar ROS levels was found early after the first noise exposure, a decrease was found in the CE and the Hip at 30 days. The activity of hippocampal CAT was increased early and remained high in ANE rats, while it was unchanged in the CE. Finally, although SOD activity was decreased immediately after the first noise exposure, its levels were increased at 30 days in ANE rats. In summary, the present study shows that an imbalance in oxidative status induced by noise exposure could underlie behavioral changes, some of which would be long-lasting.

The protective effect of a conductive hearing loss in workers exposed to industrial noise

There is controversy as to whether a conductive hearing loss protects the inner ear from the effects of loud noise. A retrospective study was carried out on 24 patients with a combination of unilateral conductive hearing loss and noise-induced hearing loss. This allowed subjects to act as their own controls. There was no statistical difference in thresholds between the two ears; possible explanations for this finding are discussed.

The protective effect of a conductive hearing loss in workers exposed to industrial noise

There is controversy as to whether a conductive hearing loss protects the inner ear from the effects of loud noise. A retrospective study was carried out on 24 patients with a combination of unilateral conductive hearing loss and noise-induced hearing loss. This allowed subjects to act as their own controls. There was no statistical difference in thresholds between the two ears; possible explanations for this finding are discussed.

Noise Levels And Hearing Protection Devices: Effect On Student Welding Performance

Recent researchers have shown that high levels of background noise have a detrimental effect on students’ abilities to perform learning tasks. Daniels (1985), Jewell (1977, 1978), and HambrickDixon found that high noise levels produced a detrimental effect on students’ abilities to perform cognitive or psychomotor skills. Jewel1 (1977, 1978) also discovered that students exposed to higher levels of sound required more time to complete assigned tasks. Another area of concern is the effect of impact or impulse noise. Research has shown that sudden impact noise (such as welding metal dropped on a concrete floor) or impulse noise (a grinding wheel intermittently coming in contact with steel) can cause actual damage to parts of the inner ear (Bohne, 1976; Luz & Hodge, 1971). Depending on the decibel level, impact or impulse noise levels can cause temporary loss of hearing activity or even result in damage that is permanent. The use of hearing protective devices (HPD’s) has been established as a sound practice to reduce the negative effect of loud noise on students’ performance levels (Feldman and Grimes, 1985; Hartley, 1974; Miller, 1986). Experimental research (Miller, 1986) has shown that HPD’s areeffective in maintaining higher levels of student performance when completing learning activities under noisy conditions. Standard maximum levels of noise exposure have been established by the Occupational Safety and Health Administration (OSHA, 1981). The maximum exposure levels and time periods during a working day without hearing protection are shown in Table 1. More recent federal regulations (OSHA, 1981) are imposing a maximum eight hour exposure limit of 85 decibels as the point where employers are required to monitor noise levels, notify employees, and recommend use of HPD’s. At noise levels of 90 decibels and above, employees are required to use HPD’s. Table 1 Permissible Exposure Time by Intensitv of Sound Pressure Level in Decibels (dBA)

Toward a psychological theory of multidimensional activation (arousal)

The traditional physiologically defined activation or arousal continuum, which ranges from intense emotion and vigorous activity on one extreme to calmness and sleep on the other, is rejected in favor of a psychological model with two activation dimensions and a single continuum of energy expenditure. One activation dimension ranges from subjectively defined feelings of energy and vigor to the opposite feelings of sleepiness and tiredness. Activation states associated with this dimension regularly vary in a circadian rhythm, and this dimension underlies gross physical activity and many aspects of cognition. The second dimension ranges from subjective tension to placidity and quietness, and it probably underlies a variety of emotions (e.g., anxiety) and stress reactions (e.g., effects of loud noise). While the two dimensions are positively correlated at moderate levels of energy expenditure, they are negatively correlated at high levels of expenditure; therefore, tension is lowest when energy-vigor is greatest and vice versa. Vulnerability to tension increases at late night, early morning, and at other times when effort and stress have increased tiredness and reduced vigorousness. Extremely low activation on either dimension de-energizes the whole system. Although only two dimensions are assumed, the possibility of four or more activation dimensions is discussed.

The Effect of Loud Noise on the Vestibular System

The Effect of Loud Noise on the Vestibular System

The Effect of Loud Noise on the Vestibular System

The effect of a 2 sec 113--123 dB ISO pure tone stimulus on ENG was studied. The material consisted of patients with operated and unoperated otosclerosis, normal ears, patients with sensorineural defects, and cases of chronic otitis media. ENG changes were found in 45% of patients with sensorineural hearing loss, in 35% of operated otosclerotics, in 15% of unoperated otosclerotics, in 15% of patients with chronic media, but in none of the normal-hearing patients. Most of the patients showing ENG changes felt dizzy. These results seem to imply a possible risk to patients with sensorineural hearing loss working in high noise levels.

Effect of Loud Noise on Attentional Selectivity

The effects of loud noise are examined by observing its influence upon a combined tracking and multi-source monitoring task. Tracking (the primary task) improves in noise, as does the detection of centrally located signals in the monitoring task. Peripheral signals are detected less often in noise. The data are interpreted in terms of increased selectivity of attention with arousal.

Reports for the Year 1914 from the Ear and Throat Department of the Royal Infirmary, Endinbugh. Part I. Noise-Deafness: A Review of Recent Experimental Work, and a Clinical Investigation into the Effect of Loud Noise Upon the Labyrinth in Boiler-Makers

Reports for the Year 1914 from the Ear and Throat Department of the Royal Infirmary, Endinbugh. Part I. Noise-Deafness: A Review of Recent Experimental Work, and a Clinical Investigation into the Effect of Loud Noise Upon the Labyrinth in Boiler-Makers - Volume 30 Issue 3

Reports for the Year 1914 from the Ear and Throat Department of the Royal Infirmary, Endinbugh. Part I. Noise-Deafness: A Review of Recent Experimental Work, and a Clinical Investigation into the Effect of Loud Noise Upon the Labyrinth in Boiler-Makers

Reports for the Year 1914 from the Ear and Throat Department of the Royal Infirmary, Endinbugh. Part I. Noise-Deafness: A Review of Recent Experimental Work, and a Clinical Investigation into the Effect of Loud Noise Upon the Labyrinth in Boiler-Makers