Tomoki Ito, Shunsuke Ishimitsu, Seiji Nakagawa
INTERNOISE 2014 - 43rd International Congress on Noise Control Engineering: Improving the World Through Noise Control 2014年1月1日
It is thought that active noise control (ANC) is able to control not only loudness but also auditory impression; however, few studies have focused on changes in the auditory impressions of noises through ANC.Some previous studies have reported significant correlations between subjective preference/annoyance of sounds and synchrony of the alpha activity, τe.In this study, auditory impressions of car engine noises varied by ANC were investigated using psychoacoustic and neurophysiological measurements. Car engine noises were modeled as harmonic complex tones. 20 stimuli were obtained by applying ANCs with several reduction-levels. First, Scheffe's paired comparison tests were performed to evaluate subjective annoyance for each stimulus. Next, magnetoencephalographic responses for the reference noise, the intermediate-, and the least-annoyed stimuli for eachparticipant were recorded, and then τe was estimated accordingly. Annoyance decreased as the cut-off frequency and the reduction-level increased. The results indicated that decrease of loudness is important for improvements in auditory impressions.However, no significant effects of ANC wereobserved in τe. It is difficult to identify the cause, the annoyancelevelsfor eachstimulus were not markedly different.