Audio filter bank with decorrelation components

Description

1 / 20 Audio filter bank with decorrelation components Separated from BR112022003131-9, deposited on 02 / 09 / 2020 CROSS-REFERENCE WITH RELATED ORDERS

[001] This application claims priority to U.S. Provisional Patent Application No. 62 / 895,096, filed September 3, 2019, the description of which is incorporated herein by reference. FIELD OF TECHNIQUE

[002] This disclosure generally refers to audio signal processing and, in particular, to audio signal processing in which a set of one or more frequency-domain input audio signals is processed to create a new set of one or more frequency-domain output audio signals. FUNDAMENTALS OF THE INVENTION

[003] In audio signal processing, it is common to convert a set of input audio signals into a new set of output audio signals, where the number of output audio signals may be equal to or greater than the number of input audio signals. For example, a sound system might convert two input audio signals (e.g., stereo audio signals) into five output audio signals using a linear matrix operation. The linear matrix operation applies a matrix to the input audio signals that includes coefficients that may vary as a function of time or frequency. The linear matrix operation can also determine a covariance of the output audio signals when the input audio signals have been subjected to decorrelation processing. SUMMARY OF THE INVENTION

[004] A multi-input multi-output audio process is implemented as a linear system for use in an audio filter bank to convert a set of frequency-domain input audio signals into a Petition 870260043132, dated 07 / 05 / 2026, page 9 / 60 2 / 20 set of frequency domain output audio signals. A transfer function from an input to an output is defined as a frequency-dependent gain function. In some implementations, the transfer function includes a direct component that is substantially defined as a frequency-dependent gain and one or more uncorrelated components that have variable frequency group phase response. The transfer function is formed from a set of sub-band functions, with each sub-band function being formed from a set of corresponding component transfer functions, including a direct component and one or more uncorrelated components.

[005] In some implementations, a method of converting a set of frequency-domain input audio signals to a set of frequency-domain output audio signals comprises: computing, using one or more processors, each frequency-domain output audio signal as a sum of filtered frequency-domain input audio signals, wherein each filter used to filter the frequency-domain input audio signals is characterized by a complex gain function over a respective sub-band frequency range of the frequency-domain input audio signal, wherein the contributions of the frequency-domain input audio signals to the frequency-domain output audio signal are determined by a composite frequency-domain gain vector, and the composite frequency-domain gain vector is obtained by: computing, using one or more processors,a set of frequency domain gain vector components, wherein at least one of the component frequency domain gain vectors is a component frequency domain gain vector decorrelation formed by augmenting the component frequency domain gain vector with additional component frequency domain gain vectors with responses of, Petition 870260043132, dated 07 / 05 / 2026, page 10 / 60 3 / 20 frequencies modified to create a decorrelation effect; and summing, using one or more processors, the component frequency domain gain vectors to form the composite frequency domain gain vector.

[006] In some implementations, the frequency domain gain vector of the decorrelation component is formed by scaling at least one of the component's frequency domain vectors by a component gain value.

[007] In some implementations, one or more of the component frequency domain gain vectors include a phase response that varies over the sub-band frequency range, thus providing a group delay that is substantially constant over the sub-band frequency, and where the group delay is substantially constant if a fluctuation in the group delay is small enough to be perceptibly insignificant to a listener.

[008] In some implementations, one or more of the component frequency domain gain vectors include a phase response that varies over the sub-band frequency range, thus providing a group delay that varies over the sub-band frequency range to provide the decorrelation effect.

[009] In some implementations, the component frequency domain gain vector decorrelation is formed by multiplying the component frequency domain gain vector by a decorrelation function.

[010] In some implementations, an audio filter bank with decorrelation components comprises: a converter configured to convert a set of time-domain input audio signals into a set of frequency-domain input audio signals; and a linear mixer configured to convert the set of frequency-domain input audio signals into a set of frequency-domain output audio signals. Petition 870260043132, dated 07 / 05 / 2026, page 11 / 60 4 / 20 where each frequency domain output audio signal is a sum of filtered frequency domain input audio signals, wherein each filter used to filter the frequency domain input audio signals is characterized by a complex gain function over a respective subband frequency range of the frequency domain input audio signal, and the contributions of the frequency domain input audio signals to the frequency domain output audio signal are determined by a frequency domain composite gain vector.

[011] In some implementations, the composite frequency domain gain vector is obtained by: computing a set of component frequency domain gain vectors, wherein at least one of the component frequency domain gain vectors is a decorrelation component frequency domain gain vector formed by augmenting the component frequency domain gain vector with additional component frequency domain gain vectors with frequency responses modified to create a decorrelation effect on the output frequency domain audio signal; and summing the component frequency domain gain vectors to form the composite frequency domain gain vector.

[012] In some implementations, the frequency domain gain vector of the decorrelation component is formed by scaling at least one of the component's frequency domain vectors by a component gain value.

[013] In some implementations, one or more of the component frequency domain gain vectors include a phase response that varies over the sub-band frequency range, thus providing a group delay that is approximately constant over the sub-band frequency, and where the group delay is approximately constant if a fluctuation in the group delay is Petition 870260043132, dated 07 / 05 / 2026, page 12 / 60 5 / 20 small enough to be noticeably insignificant to a listener.

[014] In some implementations, one or more of the component frequency domain gain vectors include a phase response that varies over the sub-band frequency range, thus providing a group delay that varies over the sub-band frequency range to provide the decorrelation effect on the frequency domain output audio signal.

[015] In some implementations, the component frequency domain gain vector is formed by multiplying the component frequency domain gain vector by a decorrelation function.

[016] In some implementations, a filter bank-based audio system comprises a converter configured to convert a set of time-domain input audio signals into a set of frequency-domain input audio signals;and a linear mixer configured to convert the set of frequency-domain input signals into a set of frequency-domain output signals, the linear mixer including weighting coefficients that provide a frequency-dependent gain function that includes a direct component that is defined as a frequency-dependent gain and one or more uncorrelated components that have a variable group phase response, the frequency-dependent gain formed from a set of sub-band functions, with each sub-band function being formed from a set of corresponding component transfer functions, including a direct component and one or more uncorrelated components.

[017] Other implementations disclosed in this document are directed to a computer-readable system, apparatus, and medium. Details of the disclosed implementations are presented in the attached drawings and the description below. Other features, objects, and advantages are evident from the description, drawings, and claims. Petition 870260043132, dated 07 / 05 / 2026, page 13 / 60 6 / 20

[018] The particular embodiments disclosed in this document provide one or more of the following advantages. The disclosed implementations integrate decorrelation processing into the audio filter bank, thus allowing input audio signals to be mapped to output audio signals using a single linear mixer, resulting in lower latency than conventional audio filter banks that perform decorrelation processing using multiple linear mixers. BRIEF DESCRIPTION OF THE DRAWINGS

[019] In the drawings, specific arrangements or orderings of schematic elements, such as those representing devices, units, instruction blocks, and data elements, are shown to facilitate description. However, it should be understood by those skilled in the art that the specific ordering or arrangement of schematic elements in the drawings is not intended to imply that a particular order or sequence of processing, or separation of processes, is required. Furthermore, the inclusion of a schematic element in a drawing does not mean that such an element is required in all embodiments or that the features represented by such an element cannot be included or combined with other elements in some implementations.

[020] Furthermore, in drawings where connecting elements, such as solid or dashed lines or arrows, are used to illustrate a connection, relationship, or association between two or more other schematic elements, the absence of such connecting elements is not intended to imply that no connection, relationship, or association may exist. In other words, some connections, relationships, or associations between elements are not shown in the drawings so as not to obscure disclosure. Additionally, for ease of illustration, a single connecting element is used to represent multiple connections, relationships, or associations between elements. For example, when a connecting element represents a Petition 870260043132, dated 07 / 05 / 2026, page 14 / 60 7 / 20 communication of signals, data or instructions, it should be understood by those skilled in the art that such an element represents one or more signal paths, as necessary, to affect communication.

[021] Figure 1 illustrates a set of filtered input audio signals to produce a set of output audio signals using a filter matrix, according to one or more modes.

[022] Figure 2 illustrates a desired frequency response curve, according to one or more modalities.

[023] Figure 3 illustrates a set of filter bank frequency responses according to one or more modes.

[024] Figure 4 illustrates a bandpass response of a typical component frequency domain gain vector, according to one or more modes.

[025] Figure 5 illustrates the frequency response of a sub-band filter with group delay that varies significantly with frequency, according to one or more modes.

[026] Figure 6 illustrates a known method for mixing an input signal to create an output signal using a direct mixing matrix and one or more decorrelation mixing matrices, according to one or more modalities.

[027] Figure 7 is a flow diagram of an example process for converting a set of frequency-domain input audio signals into a set of frequency-domain output audio signals, according to one or more modes.

[028] Figure 8 shows a block diagram of a system suitable for implementing the features and processes described in reference to Figures 1 to 7, according to one or more modalities.

[029] The same reference symbol used in several drawings indicates Petition 870260043132, dated 07 / 05 / 2026, page 15 / 60 8 out of 20 similar elements. DETAILED DESCRIPTION

[030] In the detailed description that follows, several specific details are presented to provide a complete understanding of the various embodiments described. It will be evident to one skilled in the art that the various implementations described can be practiced without these specific details. In other cases, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. Several features are described that can be used independently of each other or with any combination of other features. Nomenclature

[031] As used in this document, the term includes and its variants should be read as open terms meaning includes, but is not limited to. The term “or” should be read as “and / or” unless the context clearly indicates otherwise. The term “based on” should be read as “based, at least in part, on”. The terms “an example of implementation” and “an example of implementation” should be read as “at least one example of implementation”. The term “another implementation” should be read as “at least one other implementation”. The terms determined, determines, or determining should be read as obtain, receive, compute, calculate, estimate, predict, or derive. Furthermore, in the description and claims that follow, unless defined otherwise, all technical and scientific terms used in this document have the same meaning commonly understood by those skilled in the art to which this disclosure pertains. System Overview

[032] Figure 1 illustrates the linear mixing system 100 in which a set of input audio signals is filtered to produce a set of output audio signals, according to one or more modes. The system 100 can be Petition 870260043132, dated 07 / 05 / 2026, page 16 / 60 9 / 20 implemented, for example, in an audio filter bank. An audio filter bank includes a series of bandpass filters that separate an input audio signal into various frequency sub-bands of the input audio signal. In the example shown, the linear mixing system 100 includes a filter bank 101 and summers. 102. N input signals (Xi...Xn) are processed by the filter bank 101 and summed by the adders 102 to produce M output signals (Y1...YM). The linear mixing system 100 can be defined in terms of frequency domain input and frequency domain output signals as follows: Ai ( / )\ w)=pH VW( / ) / Oh (m Y(f) = [Y2(f)] \W) / [1] [2] Gi,i( / ) Gi,2(D G2,i(f) G2i2(f) ^Mi(f) GM,2(f) Gi,N(DG2, N(Γ) Gm.n(D \ Ai(m |xX2(f) . / V,ot / [3]

[033] According to Equation [3], the frequency domain output audio signals Y_m (f) (me[1...M]) are formed as a sum of filtered frequency domain input audio signals X_n (f), wherein the contributions of the frequency domain input audio signals X_n (f)(ne[1...N]) to Y_m (f) are determined by the frequency domain composite vector, G_(m,n) (f), according to: Υ™(ί)=Σ^η,n(f)xXn(f). (4)

[034] For the purposes of the following comment, G(f) will be referred to as an example of a frequency-domain composite gain vector, and this term should be understood as referring to any of the frequency-domain composite gain vectors G_m,n ) (f) as used in Equations [3] and [4]. Petition 870260043132, dated 07 / 05 / 2026, p. 17 / 60 10 / 20

[035] Figure 2 illustrates a desired frequency response curve for a filter, according to one or more modes. A desired frequency response of an example of a composite frequency domain gain vector can be generated by a process that creates smoothed functions, as shown in Figure 2, where the filter gain 20, as a function of frequency, is defined according to a predefined set of control frequencies fci, fc2... and corresponding component gain values ​​wi, W2.... For example, the gain 21 of a filter at frequency fc2 is defined by the component gain value W2, as shown in Figure 2. The frequency response shown in Figure 2 is obtained by the weighted sum of a number of predefined component frequency domain gain vectors.

[036] Figure 3 illustrates a set of filter bank frequency responses, according to one or more modes with the frequency band 2 response, Hq,2 (f), being referenced. The frequency responses of these predefined component frequency domain gain vectors are hereinafter referred to as component frequency domain gain vectors, Ho,b (f), for be [1...B], where B is the number of bands (e.g., B=5 in the example of Figure 3), and each of the component frequency domain gain vectors has an alternative representation in the form of a time domain impulse response, ho,b (n).

[037] In one embodiment, a desired filter response (see Figure 2) can be formed from a weighted sum of responses from a predefined filter bank. This can be expressed as a sum in the time domain or in the frequency domain: G(C^Bb=íH0,b(f)wb.[5]

[038] In some implementations, the set of component frequency domain gain vectors is augmented with domain gain vectors Petition 870260043132, dated 07 / 05 / 2026, p. 18 / 60 11 / 20 of the additional component frequency Ho,b(f) that have their frequency response modified to create a decorrelation effect. The expanded set of component frequency domain gain vectors is referred to hereafter as decorrelation component frequency domain gain vectors, which are represented with the following nomenclature: Hi,b(f) 6e[1...B], / e[0...L]. [6] where B is the number of sub-bands and L is the number of decorrelation functions.

[039] This set of component frequency domain gain vectors is augmented can be used in filter bank-based audio processing systems to generate a composite frequency domain gain vector by applying a modified form of Equation [5], as shown in Equation [7]: Hlib(O bE[1mB],lE[0mL]. [7]

[040] Figure 4 illustrates a pass-through response of a typical component frequency domain gain vector, according to one or more embodiments. In the example shown, the component frequency domain gain vector, Ho,b(f), has a magnitude response 401 that is generally dominant over a specific sub-band variation, and the group delay 402 is substantially constant over the sub-band variation. The group delay is considered substantially constant if the fluctuation in the group delay is small enough to be insignificant to a listener when the filter is used to process an audio signal.

[041] Figure 5 illustrates the frequency response of a sub-band filter with group delay that varies significantly with frequency, according to one or more modes. The frequency response of a frequency-domain gain vector with decorrelation component, such as Hl,b (f) (l ^0), exhibits a delay Petition 870260043132, dated 07 / 05 / 2026, page 19 / 60 12 / 20 of group 502 that varies along the sub-band frequency range and in which the variation in group delay is such that the input audio signals that are filtered by the frequency domain gain vector of the decorrelation component, Hi,b (f) (l ^0), are perceived as being uncorrelated from the input audio signals that are filtered by the frequency domain gain vector of the component, Ho,b (f).

[042] It is known in the art as creating frequency responses with variable group delay that vary over a wide frequency range for the purpose of creating a perceived decorrelation effect. In one embodiment, a known decorrelation frequency response can be adapted by applying a magnitude 501 response to form a frequency domain gain vector of the decorrelation component. In one embodiment, a known decorrelation function Dl(f) (le [1...L]) is used to calculate a set of frequency domain gain vectors of the decorrelation component B: Hi,b(f)=Dlx HOib(f) (be[1...B]). [8]

[043] Figure 6 illustrates a 600 system for mixing an input signal to create an output signal using a direct mixing matrix and one or more decorrelation mixing matrices, according to one or more modes. Given a set of L known decorrelation functions, Dl (f) (le [1...L]), an N-channel input signal (X) is processed by the 600 system to produce an M-channel output signal (Y). This example illustrates the processing for a sub-band (e.g., band b), where an N-channel input 601 (X) is applied to the linear direct mixing matrix 602 (C) (e.g., an M χ N matrix) to produce the direct channel signal M 603. The N-channel input 601 is also processed by the linear mixer 610 (Ql) (e.g., a KL χ N matrix) to produce a set of KL channels 611 that are passed through a bank of decorrelation filters Kl 612 (Dl), each of which applies a frequency response Dl (f) to produce Petition 870260043132, dated 07 / 05 / 2026, page 20 / 60 13 / 20 the KL channel signal 613, which is then remixed by the linear mixer 614 (Pi) (e.g., an M χ Kl matrix) to produce the channel decorrelation component signal M 615. The direct channel signal M 603 is then summed with the channel decorrelation component signals M (e.g., decorrelation component signal (615)) to produce the channel output M 602 (Y).

[044] In this embodiment, an alternative to the processing shown in Figure 6 is implemented by replacing the functions of the linear mixing matrices C, Q1...Ql and P1...PL with a single set of weighting coefficients, w^n. According to one embodiment, and referring to Equation [4], the output channel Ym (f) can be generated according to: W^£=iW / )x ^n( / ), = Σ^=ι(Σί'=οΣ^=ιΗΙ,6( / )^5η) xXn(f). [9]

[045] Equation [9] can be implemented in an audio processing system based on a filter bank, where the number of filters is (L+1) x B instead of the B filters that are known to be used in the technique. This expanded set of filters can still be considered as being the previously known B filters, with the addition of L x B filters that correspond to L different decorrelation functions.

[046] In some implementations, Equation [9] is implemented as an audio filter bank that includes a converter (e.g., a Fast Fourier Transform) configured to convert a set of time-domain input audio signals into a set of frequency-domain input audio signals Xn(f)Xn, and a linear mixer (matrix multiplication implementation operations) is configured to implement Gmn(f) = ΣΪ=οΣB=ιHι,b(f)WmnGm,n(f) = Σι=οΣB=ι Ht>b(f)WmnGm,n(f) = ΣΪ=οΣΒ=1Hι,b(r)w!'!)n to convert the set of frequency domain input audio signals, Xn(f)Xn, into a set of output audio signals of Petition 870260043132, dated 07 / 05 / 2026, page 21 / 60 14 / 20 frequency domain Ym(f)Ym(f). Each frequency domain output audio signal is a sum of filtered frequency domain input audio signals, and each filter used to filter the frequency domain input audio signals is characterized by a complex gain function over a respective sub-band frequency range of the frequency domain input audio signal. The contributions of the frequency domain input audio signals to the frequency domain output audio signal are determined by a composite frequency domain gain vector.

[047] In some implementations, Equation [9] is implemented as an audio filter bank system that includes a converter (e.g., a Fast Fourier Transform) configured to convert a set of time-domain input audio signals into a set of frequency-domain input audio signals Xn(f), and a linear mixer (software or hardware to implement sum-of-product operations) is configured to implement Gmn(f) = Σ|=οΣ^=ιHt>b(f)wmnGm,n(f) = ΣΪ=οΣBύ=ί b (f^Gm,n(f) = Σι=οΣB=ιHι,b(Dw!'!)n to convert the set of frequency-domain input audio signals, Xn(f)Xn. into a set of frequency-domain output audio signals Ym(f)Ym(f).The linear mixer includes weighting coefficients (the elements of Gm,n( / )Gm,n( / )) that provide a frequency-dependent gain function that includes a direct component, which is defined as a frequency-dependent gain, and one or more uncorrelated components having a variable group frequency phase response. The frequency-dependent gain is formed from a set of sub-band functions, with each sub-band function being formed from a set of corresponding component transfer functions, including a direct component and one or more uncorrelated components. Example Process Petition 870260043132, dated 07 / 05 / 2026, p. 22 / 60 15 / 20

[048] Figure 7 is a flow diagram of an example of process 700 for converting a set of frequency-domain input audio signals into a set of frequency-domain output audio signals, according to one or more modes. Process 700 can be implemented, for example, by the system 800 described in reference to Figure 8.

[049] Process 700 calculates each frequency domain output audio signal as a sum of filtered frequency domain input audio signals, each defining a complex gain function over a respective sub-band frequency range, wherein the contributions of the frequency domain input audio signals to the frequency domain output audio signal are determined by a composite frequency domain gain vector (701).

[050] Process 700 continues by obtaining the composite frequency domain gain vector by calculating a set of component frequency domain gain vectors (702). At least one of the component frequency domain gain vectors is a component frequency domain decorrelation gain vector formed by augmenting the component frequency domain gain vector with additional component frequency domain gain vectors having modified frequency responses to create a decorrelation effect.

[051] Process 700 continues summing the component frequency domain gain vectors to form the composite frequency domain gain vector (703). Example of System Architecture

[052] Figure 8 shows a block diagram of an example 800 system suitable for implementing example embodiments of the present disclosure. The System 800 includes one or more server computers or any device Petition 870260043132, dated 07 / 05 / 2026, page 23 / 60 16 / 20 client, including but not limited to: call servers, user equipment, conference room systems, home theater systems, virtual reality (VR) equipment, and immersive content ingestion devices. The System 800 includes any consumer devices, including but not limited to: smartphones, tablet computers, laptops, vehicle computers, game consoles, background music systems, kiosks, etc.

[053] As shown, the 800 system includes a central processing unit (CPU) 801 that is capable of performing various processes according to a program stored in, for example, a read-only memory (ROM) 802 or a program loaded from, for example, a storage unit 808 into a random access memory (RAM) 803. In RAM 803, the data needed when CPU 801 executes the various processes is also stored, as needed. CPU 801, ROM 802, and RAM 803 are connected to each other via a bus 804. An input / output (I / O) interface 805 is also connected to bus 804.

[054] The following components are connected to the I / O interface 805: an input unit 806, which may include a keyboard, a mouse or similar; an output unit 807 which may include a display such as a liquid crystal display (LCD) and one or more speakers; a storage unit 808 including a hard disk or other suitable storage device; and a communication unit 809 including a network interface card, such as a network card (e.g., wired or wireless).

[055] In some implementations, the 806 input unit includes one or more microphones in different positions (depending on the host device) allowing the capture of audio signals in various formats (e.g., mono, stereo, spatial, immersive, and other suitable formats).

[056] In some implementations, the 807 output unit includes systems Petition 870260043132, dated 07 / 05 / 2026, page 24 / 60 17 / 20 with various numbers of speakers. The 807 output unit (depending on the capabilities of the host device) can render audio signals in various formats (e.g., mono, stereo, immersive, binaural, and other suitable formats).

[057] The communication unit 809 is configured to communicate with other devices (e.g., via a network). A unit 810 is also connected to the I / O interface 805, as needed. A removable medium 811, such as a magnetic disk, an optical disk, a magneto-optical disk, a flash drive, or other suitable removable medium, is mounted in unit 810 so that a computer program read from it is installed on the storage unit 808, as required. One skilled in the art would understand that, although the system 800 is described as including the components described above, in actual applications it is possible to add, remove, and / or replace some of these components, and all such modifications or alterations fall within the scope of this disclosure.

[058] According to exemplary embodiments of the present disclosure, the processes described above can be implemented as computer software programs or on a computer-readable storage medium. For example, embodiments of the present disclosure include a computer program product including a computer program tangibly embodied in a machine-readable medium, the computer program including program code to perform methods. In such embodiments, the computer program can be downloaded and mounted from the network via the communication unit 809 and / or installed from the removable medium 811, as shown in Figure 8.

[059] Generally, various embodiments of the present disclosure can be implemented in hardware or special-purpose circuits (e.g., control circuits), software, logic, or any combination thereof. For example, the units discussed above can be implemented by Petition 870260043132, dated 07 / 05 / 2026, p. 25 / 60 18 / 20 control circuits (e.g., a CPU in combination with other components of Figure 8), thus, the control circuits may be performing the actions described in this disclosure. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device (e.g., control circuits). Although several aspects of the example embodiments of this disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques, or methods described in this document may be implemented in, as non-limiting examples, hardware, software, firmware, special-purpose circuits or logic, general-purpose hardware or controller, or other computing devices, or some combination thereof.

[060] In addition, several blocks shown in the flowcharts can be viewed as steps of the method and / or as operations that result from the operation of the computer program code and / or as a plurality of coupled logic circuit elements constructed to perform the associated function(s). For example, embodiments of the present disclosure include a computer program product including a computer program tangibly embodied in a machine-readable medium, the computer program containing program codes configured to perform the methods described above.

[061] In the context of disclosure, a machine / computer-readable medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction-executing system, apparatus, or device. A machine / computer-readable medium may be a machine / computer-readable signal medium or a machine / computer-readable storage medium. A machine / computer-readable medium may be non- Petition 870260043132, dated 07 / 05 / 2026, page 26 / 60 19 / 20 transient and may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of machine / computer-readable storage media would include an electrical connection with one or more wires, a portable computer floppy disk, a hard disk drive, RAM, ROM, an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact read-only memory disk (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[062] The computer program code for carrying out the methods of this disclosure may be written in any combination of one or more programming languages. Such computer program codes may be supplied to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing device having control circuits, such that the program codes, when executed by the computer processor or other programmable data processing device, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may run entirely on one computer, partially on the computer as a stand-alone software package, partially on the computer and partially on a remote computer, or entirely on the remote computer or server, or distributed across one or more remote computers and / or servers.

[063] Although this document contains many specific implementation details, these should not be interpreted as limitations on the scope of what can be claimed, but rather as descriptions of features that may be specific to particular modalities. Certain features that are described in this descriptive report in the context of separate modalities may also be Petition 870260043132, dated 07 / 05 / 2026, page 27 / 60 20 / 20 features implemented in combination in a single embodiment. Conversely, several features described in the context of a single embodiment may also be implemented in several embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features of a claimed combination may, in some cases, be removed from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. The logical flows described in the figures do not require the specific order shown, or sequential order, to achieve the desired results. Furthermore, other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to or removed from the described systems.Consequently, other implementations fall within the scope of the following claims. Petition 870260043132, dated 07 / 05 / 2026, p. 28 / 60

Claims

1 / 1 CLAIMS 1. Audio filter bank with decorrelation components, CHARACTERIZED in that it comprises: A converter configured to convert a set of time-domain input audio signals into a set of frequency-domain input audio signals; and a linear mixer configured to convert the set of frequency-domain input audio signals into a set of frequency-domain output audio signals, wherein each frequency-domain output audio signal is a sum of filtered frequency-domain input audio signals, wherein each filter used to filter the frequency-domain input audio signals is defined by a complex gain function over a respective sub-band frequency range of the frequency-domain input audio signal, and contributions of the frequency-domain input audio signals to the frequency-domain output audio signal are determined by a composite frequency-domain gain vector.wherein the linear mixer is additionally configured to compute a set of component frequency domain gain vectors, in which the component frequency domain gain vector of decorrelation is formed by scaling at least one of the component frequency domain vectors by a component gain value to create a decorrelation effect. Petition 870260043132, dated 07 / 05 / 2026, page 29 / 60

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