Auditory modelling for assessing room acoustics

The acoustics of a concert hall, or any other room, are generally assessed by measuring room impulse responses for one or multiple source and receiver location(s). From these responses, objective parameters can be determined that should be related to various perceptual attributes of room acoustics. A set of these parameters is collected in ISO standard 3382. However, this method of assessing room acoustical quality has some major shortcomings. First of all, it is known that the perception of the acoustics of a room is dependent on the type of source signal. This is not taken into account when only impulse responses are considered. Furthermore, because of the type of test signals used to perform such a measurement, measurements are mostly carried out in empty rooms, while the acoustics can change drastically when a room is fully occupied with people. Finally, there is evidence in the literature of cases in which the parameters sometimes do not correlate well with perception. For example, it has been found that some parameters can fluctuate severely over small measurement intervals, whereas the perceptual attributes for which these parameters should be predictors remain constant. Apparently, some important properties of the human auditory system are not taken into account sufficiently. In this thesis, a new method is proposed. The method consists of the processing of arbitrary binaural audio recordings using a binaural, non-linear auditory model. These recordings (or simulations) should be performed with a dummy head. This model simulates the most important stages of the auditory system, such as the response of the inner ear, basilar membrane and hair cells, neural adaptation and binaural interaction. Using a peak detection algorithm, the output signals of the model are split into two separate streams: one related to the source (direct sound) and one related to the environment (reverberant sound). Together with the calculation of the amount of fluctuation in the Inter
Imaging Science and Technology
Applied Sciences