Hj Heiko Martin

Measuring Sound Insulation using Deconvolution Techniques

To compare the acoustic performance of a building element with the given sound insulation requirements, measurements need to be done. Generally, a broadband noise source is used according to international standards. This method does not always work in practice due to high sound insulation values or high background noise levels. It is very inconvenient from a practical point of view or even impossible to perform an accurate sound insulation measurement for all frequency bands. A solution to this problem can be found in deconvolution techniques using mls or sweep signals. It is possible to increase the signal to noise ratio with these techniques by averaging measurements and spreading out the spectral sound energy in time. As a result an efficient use of available sound power is possible. In a laboratory is investigated how to use mls or sweep signals as a source signal and deconvolution as a measurement technique to obtain the sound insulation under noisy conditions.

Prediction of the Sound Transmission Loss of Multi‐layered Small Sized Elements

In this paper an improved method for the prediction of the sound transmission loss of multilayered finite structures, like glazing will be presented. The sound transmission loss of an infinite structure is predicted with a common transfer matrix as a function of the angle of the incident sound wave. Then Villiots spatial windowing method is applied to take into account the finiteness of the element. Usually an ideal diffuse distribution of the incident sound power is assumed and the prediction results are integrated over all angles of incidence. The obtained prediction results tend to underestimate sound transmission loss due to the dominance of the small values for gracing incidence. Often simple ad-hoc corrections are used for improvement, like Beraneks field incidence, that fail for multilayered structures. Kang suggests that the incident sound power on a surface of a room generally is Gaussian distributed on the angle of incidence and introduces a weighting function for the integration of the prediction results over the angles of incidence. New in this paper is that spatial windowing as well as a Gaussian distributed sound power is considered for the prediction of the transmission loss. The results of the prediction are validated by experiment.

S‐shaped glass also stands for soundless. Sound insulation measurements and implication for building practice

This paper brings to discussion the sound insulation of a special type of glazing by studying a S(inusoidal)‐shaped curved glass. This is been used in a concert hall (under construction in Portugal) with a forward‐thinking Rem Koolhaas’s architecture requiring nonstandard solutions: glazing with very large dimensions (22 m by 15 m) and each ‘‘S‐glass panel’’ with a wavelength of about 1.0 m and amplitude of about 0.35 m will be applied as a double facade. The restrictions in ISO 104‐3 laboratory measurements (standard test opening for glazing 1.25 by 1.50 m and niche depth of 0.45 m) were not appropriate and not completely fulfilled due to differences in dimensions between small test sample, and the real required use on site as well as the silicone joints that connect the glass elements. For these reasons, the standard test opening of 10 m2 was used. These aspects are described and analyzed. The tests results (showing satisfactory sound insulation) were essential to understand the effect of the shape and ...

Modeling structure‐borne sound transmission via pipe systems to building structures

In residential buildings many people are annoyed by noise caused by their neighbors, including structure‐borne sound caused by drinking water, sanitary, and other installations. In different building regulations, limits are set to the maximum allowable sound level caused by installations in a room. However, predictions of the sound level in the design stage are not possible. In this research, a framework for structure‐borne sound transmission models for pipe systems, including source characterization, has been developed. Further, the application possibilities of existing calculation methods in the quantification of the sound transmission have been investigated. For example, the application possibilities of the finite‐element method (FEM) and statistical energy analysis (SEA) depend on the element type, including dimensions and material (pipe, mounting, or building structure), the wave type, and the frequency area. By combining both methods, calculations for the whole audible frequency area seem possible. ...