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NOISE, INFRASOUND AND ULTRASOUND AROUND A HELICOPTER
Hrnjak Miroslav Basarić Gradimir
The objective of the investigation was to measure the overall levels of noise and to carry out the frequency analysis of noise, infrasound and ultrasound in members of a helicopter crew during flight and in mechanics around a helicopter at the halt. The measurement results showed that overall levels of noise and octave levels of acoustic pressure in observed functioning modes of the helicopter engine exceed permitted levels. The spectral analysis showed that infrasound and ultrasound do not exceed permitted levels in observed frequency ranges.
Ključne reči: Noise, infrasound, ultrasound, harmful effect, effect on man, helicopter crew, aviomechanics, helicopter, protection against noise. |