Methods: A commercially available system for the purpose of categorial loudness rating (WHF, WESTRA ELECTRONIC GmbH, Wertingen) was applied with 57 subjects with normal hearing to evaluate reference loudness level functions for 1/3-octave bandpass filtered noise and octave bandpass filtered environmental sounds.
Results: The procedure can be carried out with high reproducibility without effects of training due to repetition and only slight influence of subject sex, whereas the labeling of input device and temporal structure of the environmental sounds influence results, as does the center frequency.
Conclusions: Our results showed deviations compared with the reference functions displayed in the WHF system.