451 research outputs found
Isolation performance metrics for personal sound zone reproduction systems
Two isolation performance metrics, Inter-Zone Isolation (IZI) and
Inter-Program Isolation (IPI), are introduced for evaluating Personal Sound
Zone (PSZ) systems. Compared to the commonly-used Acoustic Contrast metric, IZI
and IPI are generalized for multichannel audio, and quantify the isolation of
sound zones and of audio programs, respectively. The two metrics are shown to
be generally non-interchangeable and suitable for different scenarios, such as
generating dark zones (IZI) or minimizing audio-on-audio interference (IPI).
Furthermore, two examples with free-field simulations are presented and
demonstrate the applications of IZI and IPI in evaluating PSZ performance in
different rendering modes and PSZ robustness
Distributed pressure matching strategy using diffusion adaptation
Personal sound zone (PSZ) systems, which aim to create listening (bright) and
silent (dark) zones in neighboring regions of space, are often based on
time-varying acoustics. Conventional adaptive-based methods for handling PSZ
tasks suffer from the collection and processing of acoustic transfer
functions~(ATFs) between all the matching microphones and all the loudspeakers
in a centralized manner, resulting in high calculation complexity and costly
accuracy requirements. This paper presents a distributed pressure-matching (PM)
method relying on diffusion adaptation (DPM-D) to spread the computational load
amongst nodes in order to overcome these issues. The global PM problem is
defined as a sum of local costs, and the diffusion adaption approach is then
used to create a distributed solution that just needs local information
exchanges. Simulations over multi-frequency bins and a computational complexity
analysis are conducted to evaluate the properties of the algorithm and to
compare it with centralized counterparts
Personal Sound Zones by Subband Filtering and Time Domain Optimization
[EN] Personal Sound Zones (PSZ) systems aim to render independent sound signals to multiple listeners within a room by using arrays of loudspeakers. One of the algorithms used to provide PSZ is Weighted Pressure Matching (wPM), which computes the filters required to render a desired response in the listening zones while reducing the acoustic energy arriving to the quiet zones. This algorithm can be formulated in time and frequency domains. In general, the time-domain formulation (wPM-TD) can obtain good performance with shorter filters and delays than the frequency-domain formulation (wPM-FD). However, wPM-TD requires higher computation for obtaining the optimal filters. In this
article, we propose a novel approach to the wPM algorithm named Weighted Pressure Matching with Subband Decomposition (wPMSD), which formulates an independent time-domain optimization problem for each of the subbands of a Generalized Discrete Fourier Transform (GDFT) filter bank. Solving the optimization independently for each subband has two main advantages: 1) lower computational complexity than wPM-TD to compute the optimal filters; 2) higher versatility than the classic wPM algorithms, as it allows different configurations (sets of loudspeakers, filter lengths, etc.) in each subband. Moreover, filtering the input signals with a GDFT filter bank (as in wPM-SD) requires lower computational effort than broadband filtering (as in wPM-TD and wPM-FD), which is beneficial for practical PSZ systems. We present experimental evaluations showing that wPM-SD offers very similar performance to wPM-TD. In addition, two cases where the versatility of wPM-SD is beneficial for a PSZ system are presented and experimentally validated.This work was supported by Grants RTI2018-098085-B-C41 (MCIU/AEI/FEDER, UE), RED2018-102668-T and PROMETEO/2019/109. The work of Vicent Moles-Cases has been supported by Spanish Ministry of Education under Grant FPU17/01288.Molés-Cases, V.; Piñero, G.; Diego Antón, MD.; Gonzalez, A. (2020). Personal Sound Zones by Subband Filtering and Time Domain Optimization. IEEE/ACM Transactions on Audio Speech and Language Processing. 28:2684-2696. https://doi.org/10.1109/TASLP.2020.3023628S268426962
An approach to generating two zones of silence with application to personal sound systems
An application of current interest in sound reproduction systems is the creation of multizone sound fields which produce multiple independent sound fields for multiple listeners. The challenge in producing such sound fields is the avoidance of interference between sound zones, which is dependent on the geometry of the zone and the direction of arrival of the desired sound fields. This paper provides a theoretical basis for the generation of two zones based on the creation of sound fields with nulls and the positioning of those nulls at arbitrary positions. The nulls are created by suppressing low-order mode terms in the sound field expansion. Simulations are presented for the two-dimensional case which shows that suppression of interference is possible across a broad frequency audio range
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