Just noticeable differences in annoyance judgment, depending on the sound source's velocity

摘要

Both the sound power level and the time pattern of a noise generated by a moving passenger car strongly depend on its velocity. Changes in these two factors affect annoyance ratings. The relationship between annoyance and the velocity of a passenger car was investigated using a binaurally simulated car pass-by. The sound source model (a passenger car) used in the simulation was developed within the European project "Harmonoise". Air-absorption and ground effect were accounted for in a simulated car pass-by. The annoyance caused by a noise generated by a passenger car moving at velocities from 25 to 130 km/h was investigated in two psychoacoustic experiments. In Experiment I participants judged noise annoyance using a 11 point (0-10) scale. A linear relationship between annoyance rating and velocity was found as a result of this experiment. The annoyance ratings were then compared with the calculated characteristics of the stimuli, such as: loudness, sharpness, L_(pAmax) and L_(AE). A linear relationship has also been found between the calculated loudness and velocity. In Experiment II, using the method of constant stimuli, minimal differences in velocity corresponding to the just noticeable differences (JND's) in annoyance were collected. The minimal velocity differences corresponding to JND in annoyance obtained for three different reference velocities (50, 90 and 110 km/h) are in the range of 11 - 15 km/h.