Aircraft noise and children: Longitudinal and cross-sectional evidence on adaptation to noise and the effectiveness of noise abatement.

Assessed the impact of noise on attentional strategies, learned helplessness, performance on cognitive tasks, and blood pressure. Third and 4th graders were tested on the same measures twice, with a 1-yr interval between sessions. Longitudinal data were used to determine whether Ss adapted to aircraft noise over the 1-yr period and to assess the effectiveness of noise abatement interventions introduced in a number of noise-impacted classrooms. Additional cross-sectional data are presented to provide further information on the utility of noise abatement. In general, there was little evidence for adaptation to noise over the 1-yr period. Noise abatement had small ameliorative effects on cognitive performance, Ss' ability to hear their teachers, and school achievement. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Port noise complaints: Verbal and behavioral reactions to airport-related noise.

Compared the verbal and behavioral reactions of a total of 716 residents living in high-, medium-, and low-noise zones surrounding a major airport, as well as in communities out of the airport's noise range. Results show that the effects of noise were highly complex. While the proportion of those reported to be bothered by noise was correlated with objectively measured noise levels, the intensity and perceived source of the noise were unrelated to reported psychological and physical symptoms, length of residence in the area, or trace measures indicating recreational use of outdoor areas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual noise and aging.

Presents evidence pertaining to the hypothesis that aging is characterized by a decrement in the ability to suppress irrelevant stimuli (perceptual noise). Although studies in the various sensory modalities generally support a perceptual noise hypothesis of aging, most of the evidence is marred by serious structural weaknesses. It is concluded that the heuristic value of such a unifying hypothesis seems, however, to justify further investigation aimed at correcting these flaws. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress and open-office noise.

Forty female clerical workers were randomly assigned to a control condition or to 3-hr exposure to low-intensity noise designed to simulate typical open-office noise levels. The simulated open-office noise elevated workers' urinary epinephrine levels, but not their norepinephrine or cortisol levels, and it produced behavioral aftereffects (fewer attempts at unsolvable puzzles) indicative of motivational deficits. Participants were also less likely to make ergonomic, postural adjustments in their computer work station while working under noisy, relative to quiet, conditions. Postural invariance is a risk factor for musculoskeletal disorder. Although participants in the noise condition perceived their work setting as significantly noisier than those working under quiet conditions did, the groups did not differ in perceived stress. Potential health consequences of long-term exposure to low-intensity office noise are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual learning reflects external noise filtering and internal noise reduction through channel reweighting

To investigate the nature of plasticity in the adult visual system, perceptual learning was measured in a peripheral orientation discrimination task with systematically varying amounts of external (environmental) noise. The signal contrasts required to achieve threshold were reduced by a factor or two or more after training at all levels of external noise. The strong quantitative regularities revealed by this novel paradigm ruled out changes in multiplicative internal noise, changes in transducer nonlinearites, and simple attentional tradeoffs. Instead, the regularities specify the mechanisms of perceptual learning at the behavioral level as a combination of external noise exclusion and stimulus enhancement via additive internal noise reduction. The findings also constrain the neural architecture of perceptual learning. Plasticity in the weights between basic visual channels and decision is sufficient to account for perceptual learning without requiring the retuning of visual mechanisms.     

Communication and noise. Speech intelligibility of airplane pilots with and without active noise compensation

Noise exposure measurements were performed with pilots of the German Federal Navy during flight situations. The ambient noise levels during regular flight were maintained at levels above a 90 dB A-weighted level. This noise intensity requires wearing ear protection to avoid sound-induced hearing loss. To be able to understand radio communication (ATC) in spite of a noisy environment, headphone volume must be raised above the noise of the engines. The use of ear plugs in addition to the headsets and flight helmets is only of limited value because personal ear protection affects the intelligibility of ATC. Whereas speech intelligibility of pilots with normal hearing is affected to only a smaller degree, pilots with pre-existing high-frequency hearing losses show substantial impairments of speech intelligibility that vary in proportion to the hearing deficit present. Communication abilities can be reduced drastically, which in turn can affect air traffic security. The development of active noise compensation devices (ANC) that make use of the "anti-noise" principle may be a solution to this dilemma. To evaluate the effectiveness of an ANC-system and its influence on speech intelligibility, speech audiometry was performed with a German standardized test during simulated flight conditions with helicopter pilots. Results demonstrate the helpful effect on speech understanding especially for pilots with noise-induced hearing losses. This may help to avoid pre-retirement professional disability.     

Background noise.

Comments that anyone familiar with the EEG literature can scarcely agree with J. T. Cacioppo and L. G. Tassinary's (see record 1990-14077-001) statement that the spontaneous EEG was long thought to represent background noise. Contrary to reliable evidence, this statement implies that the EEG contains no information relevant to brain functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reducing percussive noise

Moscow Institute of Steel and Alloys. Translated from Metallurg, No. 3, pp. 23–24, March, 1994.     

Diffusion and 1/f noise

The noise associated with ion transport through porous membranes is considered as a diffusion process. This is confirmed experimentally by measuring the noise spectra associated with pores of known dimension. It is then shown that one dimensional diffusion through pores of variable length can produce approximate 1/f noise spectra, if the distribution of lengths is proportional to (length)-1.     

Memory and search in loud noise.

Using a between-group design, 20 26–38 yr olds worked at a task requiring the sequential inspection of a facedown pack of playing cards in either 55 or 100 db white noise presented through earphones. In the loud-noise condition, Ss took less total time to detect all matching pairs and complete the task, although more cards were inspected in the process. Confidence levels associated with the detection of pairs were more extreme but were accurate predictors of correct and incorrect decisions. Inspection favored cards situated in central spatial segments. Results are discussed in the context of research on the effects of noise on memory and attention. (French abstract) (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)