Abstract
To improve the acoustical environment inside heavy trucks, psycho-acoustical experiments on noisiness to the interior noise and its effect on listening to the radio were performed using the 6-channel recording/reproduction system which has been devised to realize 3-dimensional aural impression in an acoustic laboratory. For the subjective tests, interior noises inside heavy trucks during actual running were recorded at a passenger-seat by changing the running conditions. The experimental results of the subjective hearing tests were examined using various noise indicators. Besides, the sound localization for a warning horn sound transmitted into the driver's cab was examined using the same sound field simulation system.
