Correlations between noise level and mechanical vibrations emitted by viboracoustic sources

Abstract

Economic development brings environmental concerns in general and in particular regarding the protection against the aggression of external factors on humans, among which noise and vibration. Noise is usually defined as a sound or the amount of unwanted sounds, a by-product of daily activity. Environment vibrations that human body is exposed to may have different causes: construction machinery, heavy equipment and electric hand tools. Whole human body vibrations usually occur during transport, but can be found in other places in the course of industrial processes. Regardless of industrial activity that cause them, vibrations acts on the human body and this can cause discomfort to the operator. Wear of the components of industrial devices influences both noise and mechanical vibration levels. The paper presents correlations occurring between noise and mechanical vibrations emitted by the engine of a car depending on the number of engine revs. For a broader characterization of emission, acoustic power and directivity factor are calculated.