For determination of the insertion loss, usually a harmonic frequency analysis will be performed. For this reason, noise propagating from a sound source behind an "inserted" object - e. g. a noise barrier ? is measured as sound pressure level in third octave bands and brought in relation to the situation without an inserted object. Instead of noise, other signals, such as sweeps can be used, and the analysis can be done with the method of spatial impulse response. But still the evaluation is done by means of Fourier transformation in the frequency domain. In contrast to this, with the correlation method an assessment of the "insertion" is possible in the time domain also. For this reason a combination of correlation analysis with scalable windows in the manner of wavelet analysis is conducted. For specific geometries of source, obstacle and receiver, the transit times of the different sound rays are known a priori. By correlation of the sound signals recorded at two microphones - reference and measuring point - a quantitative analysis for different wavelengths can be carried out at given transit time differences without having to transform it into the frequency domain first. In a scaled experiment, the insertion loss of a line grid of obstacles was determined both conventionally and with correlation analysis. First results will be presented.