The Impact of Standing Waves on Localization Ability of Low-Frequency Sound Sources

This paper studies the effect of room modal resonances on the localization of very low- frequency sound sources. A subjective listening test is conducted with 20 participants in an anechoic chamber, where the listener must detect the direction of the sound source for pure sinusoids at 31.5, 50, and 80 Hz. A synthetic standing wave pattern modeling a room resonant effect is created with two additional sound sources located at the left and right sides of the listener. Results show that the perception of low-frequency direction is negatively impacted by the node of the standing wave, even when the standing wave has a relatively low level, whereas the antinode does not have as strong of an effect. The second experiment conducted indicates that variations in the presentation level does not impact the effect of the standing wave. The results of this study suggest that in the low-frequency spectrum, direction judgement is not so strongly a question of this auditory system's ability but more so of the acoustical properties of the listening environment.