Auralization based on multi-perspective ambisonic room impulse responses

Abstract

Most often, virtual acoustic rendering employs real-time updated room acoustic simulations to accomplish auralization for a variable listener perspective. As an alternative, we propose and test a technique to interpolate room impulse responses, specifically Ambisonic room impulse responses (ARIRs) available at a grid of spatially distributed receiver perspectives, measured or simulated in a desired acoustic environment. In particular, we extrapolate a triplet of neighboring ARIRs to the variable listener perspective, preceding their linear interpolation. The extrapolation is achieved by decomposing each ARIR into localized sound events and re-assigning their direction, time, and level to what could be observed at the listener perspective, with as much temporal, directional, and perspective context as possible. We propose to undertake this decomposition in two levels: Peaks in the early ARIRs are decomposed into jointly localized sound events, based on time differences of arrival observed in either an ARIR triplet, or all ARIRs observing the direct sound. Sound events that could not be jointly localized are treated as residuals whose less precise localization utilizes direction-of-arrival detection and the estimated time of arrival. For the interpolated rendering, suitable parameter settings are found by evaluating the proposed method in a listening experiment, using both measured and simulated ARIR data sets, under static and time-varying conditions.

Locating Image Sources from Multiple Spatial Room Impulse Responses

“…Therefore, one might argue that it is especially important to render the early reflections correctly in 6DoF auralizations. In fact, Müller and Zotter [25] have recently presented a measurement-based rendering system that works on first order Ambisonics impulse responses. Additionally, there are several other methods for rendering continuous sound signals in 6DoF [26][27][28][29][30][31][32][33] that could be potentially adapted to process impulse responses as well.…”

Six-Degrees-of-Freedom Parametric Spatial Audio Based on One Monaural Room Impulse Response

“…More recently proposed methods for 6-DoF rendering typically require at least one [7,8] or even multiple SRIRs [9,10] from different positions in the room and apply extrapolation based on one SRIR or interpolation between the distributed SRIRs to incorporate listener translation. How-ever 6-DoF rendering based on a parametric description of the sound field at one position in the space, encoded from a single RIR measurement, is rare.…”

“…Recent work extended those methods to render the sound field for 6 DoF and thus for arbitrary head orientations and room positions of the listener. The methods typically require at least one or even multiple SRIRs from different positions in the room and derive a description of the sound field at arbitrary positions by extrapolation based on one SRIR (e.g., [7,8]) or by interpolation between the distributed SRIR measurements (e.g., [9,10]). For a comprehensive overview of 6-DoF rendering methods please refer to [10].…”

Spatial Subtraction of Reflections from Room Impulse Responses Measured with a Spherical Microphone Array

“…The DRIR was measured with an Eigenmike em32 microphone array (N = 4) and a Genelec 1030A loudspeaker at a distance of 2.5 m. In particular, this study uses measurement position 2 of the data set, where a table is located between the source and the receiver. To detect the most prominent directional peaks in the DRIR, the peak finding algorithm from [21,22] was implemented. The algorithm analyzes the averaged magnitude of the pseudo-intensity vector i(t) = w(t) x(t), y(t), z(t) T , that is obtained from the zeroth and first-order SH components of the DRIR, i.e., the first four channels w(t), y(t), z(t), x(t), if ordered according to the Ambisonic channel number (ACN) sequence [23].…”