Low-frequency noise and infrasound: Towards to a single descriptor to their assessments

Montano W.A.; Gushiken E.I. · "Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021 (2021)

Resumen

Since 1969 when Botsford introduced the idea of the difference between dBC minus dBA values, it could indicate the amount energy in low-frequency range, several researcher have been introduced some rating curves or some descriptor to assess the low-frequency noise contained in a sound spectrum. WHO recommends the use of dBC-dBA and it suggests when that difference is greater than 10 dB an analysis should be applied, but it doesn't say anything about the bandwidth, so it supposed to use the whole frequency band. After the introduction of DIN 45680 Standard in 1997, the idea of applying the difference between dBC minus dBA but using just only the low frequency band, it has been a big advance into low-frequency noise assessment policy; the latest version asks to evaluate the frequency range from 8 Hz to 125 Hz. In the case of Barcelona city, the Environmental Authority uses to evaluate the amount of low-frequency noise impact, by using the difference between dBC minus dBA but using from 20 Hz to 160 Hz. The concept of applying the dBC-dBA using the whole bandwidth has been improved over the years, but now the threshold value rose up to 20 dB. In this Paper the authors are proposing to use one single standardized descriptor based on ISO 1996 low-frequency band definition, in the sense of using dBC-dBA from 16 Hz to 200 Hz, because it is more accurate to apply this criteria instead of the whole bandwidth since includes energy in middle and high frequencies. © "Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021. All rights reserved.