Investigation of the unpleasantness of infrasound combined with audio sound using psychoacoustic scaling methods
* Presenting author
At many immission sites, human exposure to infrasound (f < 20 Hz) is usually accompanied by sound in the audio-frequency range (audio sound, 20 Hz < f < 20 kHz). This gives rise to the question of whether the interaction between infrasound and audio sound affects the quality of auditory perception. Psychoacoustic experiments were performed within the framework of the European project EMPIR 15HLT03 Ears 2. Recent results in this project had already shown that detection thresholds for infrasound were increased when simultaneous audio sound is present. The current study deals with the hypothesis that the unpleasantness related to infrasound is changed when infrasound is presented along with audio sound. A rating task on a numerical scale and a pairwise comparison task were conducted to quantify and to compare the unpleasantness of (1) isolated infrasound (sinusoid), (2) isolated audio sound (sinusoid and broadband), and (3) the combination of both, at different sound pressure levels. Normal hearing listeners aged 18 to 30 years participated in the hearing tests. The results should be of use to improve the understanding of the impact of combined noise on humans and their well-being in the vicinity of potential noise sources.