Schriftenreihe des Vereins für Wasser-, Boden- und Lufthygiene
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Schriftenr Ver Wasser Boden Lufthyg · Jan 1993
Night aircraft noise index and sleep research results.
A number of countries have introduced regulations for the protection of people living around airports against the high level of aircraft noise. Certain noise indices have been determined for 24-hour periods, others for extended daytime periods, while a few are weighted for the noise occurring during the night. ⋯ Research yields some useful results with regard to our understanding of the effects of noise and the duration and quality of sleep of people living around airports. In this paper we consider how these results can be used in proposing some noise criteria corresponding to the preservation of a certain quality of sleep.
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Schriftenr Ver Wasser Boden Lufthyg · Jan 1993
Results of a low-altitude flight noise study in Germany: acute extraaural effects.
This paper begins by outlining the aims which our study into the acute effects of low-altitude flight noise set out to achieve. The key question here concerns the relationship between noise parameters (maximum sound level and sound level rise rate) and specific reactions by the individuals affected. The subjects, healthy volunteers, were exposed via earphones to digitally recorded MLAF noise, using sophisticated recording technology. ⋯ A sensitization is observed after repeated exposure, with the startle reaction intensifying or else being triggered off by lower sound levels. The sensitization of startle reactions is neuro-physiologically associated with unpleasant or fear-inducing environmental stimuli. Together with the observed increases in plasma hydrocortisone and changes in magnesium metabolism of a type characteristic of stress, this phenomenon of sensitization enables us to establish the hypothetical link between specific acute reactions to MLAF noise and long-term health effects.
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Schriftenr Ver Wasser Boden Lufthyg · Jan 1993
The influence of military low-altitude flight noise on the inner ear of the guinea pig. Part I: Hearing threshold measurements.
The auditory thresholds of about 60 anaesthetized guinea pigs were determined at 3 or 4 frequencies between 2 and 20 kHz using the acoustically evoked brain stem potentials. The animals were then exposed to electro-acoustically reproduced MLAF noise with peak levels between 120 and 130 dB(A). The exposure occurred either once or else four times within either 3 or 60 minutes. ⋯ In over half the animals, exposure to rapidly increasing noise level with a peak of 126 dB(A) induced PTS > or = 30 dB for at least one frequency. Exposure to a slowly increasing noise level with the same peak provoked significantly smaller PTS. 4 exposures to a rapidly rising noise level within 3 minutes induced significantly smaller PTS than the same dosage within 60 minutes. Only in the latter case was PTS greater than TTS.