Annoyance of Audible Infrasound

Abstract

Contours of equal annoyance were determined for pure tones in the frequency range 4 – 31.5 Hz. The curves show a narrowing of the dynamic range of the ear at low frequencies. The same pattern is seen for equal loudness curves, and the results support the theory that the annoyance of infrasound is closely related to the loudness sensation. Annoyance ratings of 1/3 octave noise did not deviate from ratings of pure tones with the same sound pressure level. Combinations of audio and infrasonic noise were in general given a rating close to or slightly above the rating of the most annoying of the individual noise conditions. For infrasound the proposed G1-weighting curve is shown to give values that correlate well with subjective annoyance rating. Values obtained with the G2-curve do not correlate as well. Low audio frequencies are not covered by the G-curves, and it is shown that these are insufficiently covered by the A-curve. Further research is needed in this area.