3D Room Geometry Inference Using a Linear Loudspeaker Array and a Single Microphone

Abstract

Sound reproduction systems may highly benefit from detailed knowledge of the acoustic space to enhance the spatial sound experience. This article presents a room geometry inference method based on identification of reflective boundaries using a high-resolution direction-of-arrival map produced via room impulse responses (RIRs) measured with a linear loudspeaker array and a single microphone. Exploiting the sparse nature of the early part of the RIRs, Elastic Net regularization is applied to obtain a 2D polar-coordinate map, on which the direct path and early reflections appear as distinct peaks, described by their propagation distance and direction of arrival. Assuming a separable room geometry with four side-walls perpendicular to the floor and ceiling, and imposing pre-defined geometrical constraints on the walls, the 2D-map is segmented into six regions, each corresponding to a particular wall. The salient peaks within each region are selected as candidates for the first-order wall reflections, and a set of potential room geometries is formed by considering all possible combinations of the associated peaks. The room geometry is then inferred using a cost function evaluated on the higher-order reflections computed via beam tracing. The proposed method is tested with both simulated and measured data.

A Room Impulse Response Measurement Method Robust Towards Nonlinearities Based on Orthogonal Periodic Sequences

“…As can be expected, equations (33) and (34) show that MSD j is proportional to the noise power σ 2 ν . Moreover, MSD j is proportional to < z(n) 2 > L and, thus, inversely proportional to < x 2 (n) > L , i.e., the energy of the input sequence over a period, as it can be seen from (17). For a constant power of x(n), < x 2 (n) > L is proportional to L. Consequently, MSD j is also inversely proportional to the period L. Similar to all other cross-correlation methods, the accuracy of the estimation can be improved by increasing the period L or by computing the cross-correlation over multiple periods.…”

“…O NE of the most common operations in acoustics and audio processing is the measurement of the room impulse response (RIR). The measurement is used to estimate the characteristics of the acoustic environment [1], [2] and to compensate, improve, or exploit these characteristics [3]- [17]. Many different approaches have been proposed over the years.…”

Gridless 3D Recovery of Image Sources From Room Impulse Responses

“…Most approaches make use of room impulse responses (RIRs), but some tackle the question blindly, namely, with no knowledge of the source signals [12]- [14], [20], [24], [33], [41], [45], [46], while other approaches assume that the times of arrival of acoustic reflections are directly available [8], [15], [16], [22], [26], [27], [35], [36]. Most approaches make use of multiple microphones at arbitrary known locations, but some use a single microphone [11], [15], [26], [27], [29], [42], [43], [48] or specific microphone array geometries such as spherical [20], [23], [31], [40], [45], [46], circular [14], [25], [50], linear [9], [28], or others [21], [30], [39]. Most approaches use a single sound source, but some use multiple sources [8], [11], [12], [16], [21], [30], [33],…”

“…Most approaches make use of multiple microphones at arbitrary known locations, but some use a single microphone [11], [15], [26], [27], [29], [42], [43], [48] or specific microphone array geometries such as spherical [20], [23], [31], [40], [45], [46], circular [14], [25], [50], linear [9], [28], or others [21], [30], [39]. Most approaches use a single sound source, but some use multiple sources [8], [11], [12], [16], [21], [30], [33], [35], [37], [39], [40] or a linear loudspeaker array [38], [43], [48]. Some approaches require specific geometrical assumptions on the setup, such as a rectangular or cuboid ("shoebox") room [21], [26], [33], [42], [47], [48] or having all sources and microphones lying on a plane parallel to both the floor and ceiling [11], [19], [21],…”

“…Most approaches use a single sound source, but some use multiple sources [8], [11], [12], [16], [21], [30], [33], [35], [37], [39], [40] or a linear loudspeaker array [38], [43], [48]. Some approaches require specific geometrical assumptions on the setup, such as a rectangular or cuboid ("shoebox") room [21], [26], [33], [42], [47], [48] or having all sources and microphones lying on a plane parallel to both the floor and ceiling [11], [19], [21], [43], [48]- [50]. Some approaches focus on the 2D case [13]- [15], [17], [26]- [28], [33], [44] or the 1D case [29].…”