Comparison of loudness perception mismatch with visual presentation of two anechoic rooms
A loudness mismatch between loudspeaker and headphone presentation may occur even if the same acoustical stimulus at the eardrums is presented. A preceding investigation reported an unexplainable discrepancy in mismatch across anechoic room conditions in Oldenburg and Aachen. This study tested differences in room acoustics and in other non-acoustic influences as the potential causes for the observed discrepancy.A headphone-only condition was employed where the visual presentation was varied using a head mounted display. To systematically separate potential acoustic difference between the rooms from the influence of the visually perceived room information, the headphone-equalized stimuli recorded with a head and torso simulator in the two anechoic rooms or diotic signals were presented acoustically while the visual presentation included both rooms or darkness. The level difference found in the comparisons including a diotic playback tests the dependence of the mismatch on the visually perceived rooms. Conversely, differences found in acoustical room comparisons for the same visual input allow to pinpoint the influence of the acoustic room perception. The consequences of the findings for presentation techniques in virtual acoustics (e.g., a “virtual loudspeaker”) using headphone presentations will be discussed.