Noise analysis in the engine room of a river ship on the Danube by eight methods

Abstract

In this paper was analysed the noise generated by 2 engines (with a sound level of 85.3dB and 96.1dB respectively) of a river vessel navigating on the Danube, by 8 methods divided into 4 categories: Part I - The 2 sources (engines) work simultaneously; Part II - The 2 sources (engines) work consecutively; Part III - Sonometry and Part IV - Dosimetry. In Part I noise was studied in 4 cases: Case 1) Estimation of the combined noise level of two acoustic sources; Case 2) Logarithmic addition of sound levels; Case 3) Combined noise source and distance calculator; Case 4)
Multiple noise sources calculator - Point source model: In this case, the directivity of the noise source is also taken into account. The resulting cumulative noise (96dB) is unusual because it resembles cases 1, 2 and 3 when the distance was not taken into account. In Part II the noise was studied in 2 cases: Case 5) Noise exposure ready reckoner (daily and weekly exposure): the daily and weekly noise exposure is between 93 to 94dB, close to the other cases. Case 6) Daily Noise Exposure Calculator and Weekly Noise Exposure Calculator: the results are similar In Part III
the noise was measured with the sound level meter Case 7) Graphic analysis of a complex sound: In this case, the sonogram has many more characteristics: sound level, frequency and time. In Part IV the noise was measured with the dosimeter Case 8) Noise dose calculation: This device is most useful in a workplace where the noise usually varies in duration and intensity and where the person changes locations, because it is connected to the person, giving continuous information right next to the point of interest: the ear.