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The ANIR Corpus - Background Noise


For a simulation of a realistic acoustic environments inside verhicles, representative background noises are measured and recorded by microphones in numerous positions in the car. For this, several standard car microphones and ear microphones are used. You can find more information about the number, types and positions of the microphones in the section "Microphones". Generally, background noises in different driving conditions are measured. The conditions differ in the speed (currently between 0 and 200 km/h) and the air condition level (low, middle and high level).



All channels of one recording are properly synchronized. Where the microphone positions allow for it, the recordings can, consequently, also be used in the context of array processing.


Calibration and Equalization

All channels were calibrated using a 1 kHz calibrator such that 114 dBSPL at the microphones corresponds to an unweighted digital power level of -10 dB. A digital power level of -10 dB may be interpreted as -10 dBov if the allowed value range of the signals is [-1,+1]. Calibration was performed before ear equalization, which was part of the post-processing and is included in the provided recordings. Equalization was achieved using linear-phase filters in order to keep all channels synchronized.


Analysis and Download

All recordings are presented below in four different analyses per microphone and condition. The first plot shows the time-domain signal and the second one a time-frequency analysis. In the third diagram you can see an estimate of the power spectral density and the last one shows the terz-smoothed version of the power spectral density. Furthermore, you can listen to each noise example for each microphone and situation. The wav files can be downloaded below as single files or in a zipped version of all files in the section "Downloads".


Vehicle-specific Information