Basic Considerations for Loudness-Based Analysis of Room Impulse Responses

Abstract

Room impulse responses (RIRs) are used to characterise the acoustical conditions inside soundcritical rooms such as auditoria. The analysis of RIRs typically involves octave-band filtering, with parameters such as reverberation time, early decay time, temporal energy ratios and spatial parameters derived from this. This paper explores the potential for applying auditory models for the analysis of RIRs-incorporating auditory temporal integration (and masking), auditory filterbank analysis, and loudness calculation. The purpose of this is to produce analysis results that are closely related to the sound experienced by listeners. A preliminary step for such analysis is to filter RIRs so that their power spectrum is similar to that of typical material that would be listened to in the rooms (e.g. music or speech), and this paper proposes a music filter suitable for orchestral music, derived from long term power spectra of anechoic music recordings. Dynamic loudness analysis of RIRs yields loudness decay functions that are approximately exponential, which should provide a useful analogy with conventional analysis methods applied to RIRs.

Separability of Distortion Products in Room Impulse Response Measurements with Maximum Length Sequences

“…A room impulse response (IR) has attracted special attention in room acoustics [1][2][3], since it has become a descriptor of room properties. Measurement of a room IR can be carried out applying various excitation signals [4][5][6][7].…”

“…The distribution of the MLS kernels in the recovered response is observed by crosscorrelating the MLS signal, m(r) = x(r), with the right side of eqn (1) and (2). The first ten slices of the second order MLS kernel obtained by eqn (2) for l=1, … , 10 are presented in Figure 2(a).…”

Equal Reverberance Contours for Synthetic Room Impulse Responses Listened to Directly: Evaluation of Reverberance in Terms of Loudness Decay Parameters

“…Previous studies of Lee and Cabrera [16,5,6] and of Lee et al [7] tested the idea of using the loudness decay function, derived from such models, in deriving a reverberance predictor. The underlying concept is that reverberance should be related to the modelled loudness decay rate, as this aims to approximate what people hear rather than representing the physical decay of sound.…”