Findeis, H. Peters, E. Disturbing Effects of Low Frequency Sound Immissions& Vibrations…
Disturbing Effects of Low Frequency Sound Immissions and Vibrations in Residential Buildings
Findeis H, Peters E. Disturbing effects of low frequency sound immissions and vibrations in residential buildings. Noise Health [serial online] 2004 [cited 2016 May 11];6:29-35.
NOISE & HEALTH
A Bimonthly Inter-disciplinary International Journal
Noise immissions with predominant low frequency sound components may exert considerably disturbing effects in dwellings. This applies in particular to sounds which are excitated by transmission of structure-borne noise, and to low frequency sounds emitted by ventilators. Exposed persons usually declare such immissions as being “intolerable” even at very low Aweighted sound levels. 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. For the most part the immissions are observed as vibratory effects on the building and on objects inside the dwelling. 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.
As 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).
These findings gave rise to investigations designed to answer the following questions:
(1) Are the differences in the perception of different noises just accidental occurrences, or do they follow a systematical pattern?
(2) Which noise characteristics are responsible for differences in noise perception?
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. The same method was used in cases of vibrations.
Disturbing Effects of Noise Immissions
In the preceding paragraphs it has been pointed out that as regards noise immissions with a considerable proportion of low frequency sounds in private dwellings, more than half of the complaints were made on the grounds of sleep disturbance. Quite often symptoms like “a roaring in the head, especially when lying down” were brought forward. Time and again, “a feeling of riding a lift” was reported, and over and again the measuring team had the impression that the reported immissions meant a nerve-racking experience for the exposed persons. Several complainants even got into a state of being aggressive. There were reports by a number of trustworthy persons on how they at first – for instance when moving into the flat – did not even notice any immissions. But in the course of a few weeks they began to perceive them distinctly and became intolerable after continued exposure. It was obvious that in these cases a sensibility of specific noise components had developed. Thus, it is understandable that non-exposed persons were at a difficulty to even acknowledge such noise immissions.
Findeis H, Peters E. Disturbing effects of low frequency sound immissions and vibrations in residential buildings. Noise Health [serial online] 2004 [cited 2016 May 11];6:29-35. Available from: http://www.noiseandhealth.org/text.asp?2004/6/23/29/31665