Abstract
KEYWORDS – Diesel, Diesel Knocking Noise, Psychoacoustic, temporal masking, frequency masking
ABSTRACT – a new method is required to quantify the knocking sound. The frequency bandwidth of diesel knocking sound is ranged between 0.7 kHz and 4kHz. It is amplitude and frequency modulated signal. The modulation frequency of this sound is the half order of the rotating speed of the crankshaft. In order to control the knocking sound, the masking sound is designed and applied. In order to validate the effect of masking, the quantification method of the knocking sound is to be need. In the paper, diesel sound index is developed to evaluate the masking effect based on the signal processing. The effect of masking sound is validated by using the new developed diesel sound index. After better result using time-frequency masking effects, the paper gives practical method of quantitative analysis about diesel knocking sound.