#OLD OFFICE SOUND EFFECTS HOW TO#

Parallel to measurements of floor vibrations connected with vibration immissions of frequencies below 20 Hz, not only the statements of the exposed persons regarding the immissions, but also observations made by the persons performing the measurements with regard to the immissions were documented and correlated with the measurement results. In addition, third octave sound levels and, in the case of structure-borne sound immissions, also the vibration velocity levels of the indoor wall surfaces were frequently measured. The technique of the measuring devices ensured that frequency components distinctly below 20 Hz (infrasound) did not interfere with the measuring results. To clarify question (2) quoted above, linweighted noise levels were initially assessed in addition to A-weighted levels. Discussion of the results included statements of the affected persons on the respective effects of the immissions. Secondly, the distribution functions of the measuring data regarding the various noises were taken under consideration. In most cases, structure-borne sound sources were circulator pumps in heating systems and other technical building equipment, refrigerators and ventilators in commercially used premises of dwelling buildings. * Measured values of airborne sounds emanating from structure-borne sound immissions. Measured values of other airborne transmitted sounds.The same method was used in cases of vibrations.Īs a first step in answering question (1) quoted above, the measured values obtained from the initial input evaluation were categorised according to their sources:

In order to clarify these questions the complaints were therefore analysed, on the one hand by evaluating spontaneous statements on the effects of noise immissions by the persons involved, and on the other hand by taking measurements of Aweighted noise levels and additionally carrying out acoustical measurements. (2) Which noise characteristics are responsible for differences in noise perception? (1) Are the differences in the perception of different noises just accidental occurrences, or do they follow a systematical pattern? These findings gave rise to investigations designed to answer the following questions: Available from: Īs early as in the seventies, sound level measurements carried out to verify complaints about annoying noises in dwellings have shown the following: Noises which in many cases induced vehement complaints were to a large extent of rather low sound levels, whereas the effects of simultaneous other noise immissions of higher sound levels like the ticking of a clock or intermittent traffic noise did not cause annoyance (Findeis and Thielebeule, 1979). Disturbing effects of low frequency sound immissions and vibrations in residential buildings.

#OLD OFFICE SOUND EFFECTS HOW TO#

How to cite this URL: Findeis H, Peters E. Keywords: Low frequency sound, structure-borne sound, annoying effects, sensibilisation, low frequency vibrations, road traffic induced vibrations, disturbing factors How to cite this article: Findeis H, Peters E. The disturbing effects of vibration frequencies above 20 Hz (structure-borne sound) are determined by the airborne sound field generated inside a particular room and its given surface and extension.

For the most part the immissions are observed as vibratory effects on the building and on objects inside the dwelling. If mechanical vibrations in the frequency range below 20 Hz (ground-borne vibrations) affect dwelling rooms, the annoying effects are perceived only by a small portion of exposed individuals as a physical effect. Exposed persons usually declare such immissions as being 'intolerable' even at very low Aweighted sound levels. This applies in particular to sounds which are excitated by transmission of structure-borne noise, and to low frequency sounds emitted by ventilators. Noise immissions with predominant low frequency sound components may exert considerably disturbing effects in dwellings. Disturbing effects of low frequency sound immissions and vibrations in residential buildingsīrandenburg State Environmental Agency, Germany

Old office sound effects