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Description
Structure-borne transfer functions enable the analysis of the frequency-dependent transfer behaviour of linear, time-invariant structures. While complex narrowband transfer functions are typically evaluated to assess specific system properties, building acoustics classically describes the behaviour of components using spectra in one-third-octave bands and spatial averaging. For structure-borne sound transmission, the normalized impact sound pressure level is the established metric. EN 12354-5 defines transfer functions as the ratio of the sound pressure levels to the excitation to describe this transmission. Although this quantity is usually determined using narrowband data and subsequently reduced to one-third-octave bands for prediction purposes, this study evaluates the feasibility of direct one-third-octave band measurements.The methodology compares narrowband reference measurements with the direct acquisition using a two-channel sound level analyser in laboratory conditions across a separating ceiling. The investigations cover the direct relationship HpF between sound pressure level and force level as well as the determination of the installed structure-borne power level LW,inst as a reference. Various signal processing modes were tested, including the equivalent continuous sound pressure level Leq and the maximum sound pressure level using both Fast and Impulse time weightings LF,max and LI,max.Initial investigations suggest that evaluating single impact excitation correlates well with integrated narrowband data. The results of direct measurement in one-third-octave bands indicate good agreement, though frequency-dependent deviations, particularly in higher frequency ranges, are observed and discussed. Overall, the study demonstrates that direct one-third-octave analysis can provide an efficient framework for evaluating transmission paths in practical building acoustics.