Measurement of time variant sound pressure levels at low frequencies in buildings - verification of sound class using EN ISO 10052 and 16032
Invited paper
Simmons akustik / Luleå Univ.of Techn.
Wednesday 3 june, 2015, 09:20 - 09:40
Auditorium 2 (592)
Abstract:
Low frequency sounds from heat pumps, fans, coolers and other building service equipment may be annoying to occupants even when their A-weighted equivalent sound pressure level in adjoining dwellings is low, e.g. 25-30 dB. Swedish sound classification schemes set limits on the sound levels in habitable rooms since 1996, in each third octave band 31-200 Hz. Additionally, non-stationary fluctuating sound sources nearby, in e.g. entertainment establishments, industry or commercial premises may be annoying to occupants, especially in the night or evening. The measurement uncertainty of the standardized verification methods has been studied empirically and a test code based on EN-ISO 10052 has been developed. It is intended to improve the reproducibility of this survey standard and be more practical in the field than the technical method in EN-ISO 16032, with respect to time variation of the sound level as well as the spatial variation within a room. The test code implements an evaluation scheme where measurements are repeated until the variations in sound pressures fulfill criteria for an acceptable deviation, which should reduce the temporal and spatial uncertainty with the sampling method. This procedure replaces the time consuming search for the corner position with the highest C-weighted sound pressure level in EN ISO 16032. However, more experience has to be gathered in the field before a revision of the current international standards can be initiated. The method may be used in current sound classification schemes.