# US 11,445,299 B2 · Rendering binaural audio over multiple near field transducers

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- Number: US 11,445,299 B2
- Document ID: US11445299B2
- Status: Granted
- Kind: B2
- Application number: 17/262,509
- Filed: 2019-07-23
- Published: 2021-09-23
- Granted: 2022-09-13
- Earliest claimed: 2018-07-23
- Assignees: Dolby Laboratories Licensing Corporation
- Applicants: Dolby Laboratories Licensing Corporation
- Inventors: Mark F. Davis; Nicolas R. Tsingos; C. Phillip Brown
- Web page: https://patentgrep.com/patent/US11445299B2

## CPC

- H04R 5/033: Headphones for stereophonic communication {(details thereof, e.g. relating to batteries, cables or control elements H04R1/10)}
- H04S 7/30: {Control circuits for electronic adaptation of the sound field}
- H04S 7/304: {For headphones}
- H04R 2205/022: Plurality of transducers corresponding to a plurality of sound channels in each earpiece of headphones or in a single enclosure
- H04R 2205/024: Positioning of loudspeaker enclosures for spatial sound reproduction
- H04S 2400/11: Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S2420/13 takes precedence)
- H04S 2420/01: Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD]
- H04S 2420/03: Application of parametric coding in stereophonic audio systems
- H04S 2420/11: Application of ambisonics in stereophonic audio systems
- H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K)
- H04S: STEREOPHONIC SYSTEMS

## Abstract

An apparatus and method of rendering audio. A binaural signal is split on an amplitude weighting basis into a front binaural signal and a rear binaural signal, based on perceived position information of the audio. In this manner, the front-back differentiation of the binaural signal is improved.

## Claims

### Claim 1

A method of rendering audio, the method comprising:
receiving a spatial audio signal, wherein the spatial audio signal includes position information for rendering audio;
processing the spatial audio signal to determine a plurality of weights based on the position information;
rendering the spatial audio signal to form a plurality of rendered signals, wherein the plurality of rendered signals are amplitude weighted according to the plurality of weights, and wherein the plurality of rendered signals includes a plurality of binaural signals that are amplitude weighted according to the plurality of weights;
combining the plurality of rendered signals into a joint rendered signal;
generating metadata that relates the joint rendered signal to the plurality of rendered signals; and
providing the joint rendered signal and the metadata to a loudspeaker system.

### Claim 2 (depends on 1)

The method of claim 1, wherein rendering the spatial audio signal to form the plurality of rendered signals comprises:
rendering the spatial audio signal to generate an interim rendered signal; and
weighting the interim signal according to the plurality of weights to generate the plurality of rendered signals.

### Claim 3 (depends on 1)

The method of claim 1, wherein the plurality of weights correspond to a front-back perspective applied to the position information.

### Claim 4 (depends on 1)

The method of claim 1, wherein rendering the spatial audio signal to form the plurality of rendered signals corresponds to splitting the spatial audio signal, on an amplitude weighting basis, according to the plurality of weights.

### Claim 5 (depends on 1)

The method of claim 1, wherein the spatial audio signal includes a plurality of audio objects, wherein each of the plurality of audio objects is associated with a respective position of the position information;
wherein processing the spatial audio signal includes processing the plurality of audio objects to extract the position information; and
wherein the plurality of weights correspond to the respective position of each of the plurality of audio objects.

### Claim 6 (depends on 1)

The method of claim 1, wherein each of the plurality of rendered signals is a binaural signal that includes a left channel and a right channel.

### Claim 7 (depends on 1)

The method of claim 1, wherein the plurality of rendered signals includes a front signal and a rear signal, wherein the front signal includes a left front channel and a right front channel, and wherein the rear signal includes a left rear channel and a right rear channel.

### Claim 8 (depends on 1)

The method of claim 1, wherein the plurality of rendered signals includes a front signal, a rear signal, and another signal, wherein the front signal includes a left front channel and a right front channel, wherein the rear signal includes a left rear channel and a right rear channel, and wherein the other signal is an unpaired channel.

### Claim 9 (depends on 1)

The method of claim 1, further comprising:
generating, by the loudspeaker system, the plurality of rendered signals from the joint rendered signal using the metadata; and
outputting, from a plurality of loudspeakers, the plurality of rendered signals.

### Claim 10 (depends on 1)

The method of claim 1, further comprising:
generating headtracking data;
computing, based on the headtracking data, a front delay, a first front set of filter parameters, a second front set of filter parameters, a rear delay, a first rear set of filter parameters, and a second rear set of filter parameters;
for a front binaural signal that includes a first channel signal and a second channel signal:
generating a first modified channel signal by applying the front delay and the first front set of filter parameters to the first channel signal;
generating a second modified channel signal by applying the second front set of filter parameters to the second channel signal;
for a rear binaural signal that includes a third channel signal and a fourth channel signal:
generating a third modified channel signal by applying the second rear set of filter parameters to the third channel signal;
generating a fourth modified channel signal by applying the rear delay and the first rear set of filter parameters to the fourth channel signal;
outputting, from a first front loudspeaker, the first modified channel signal;
outputting, from a second front loudspeaker, the second modified channel signal;
outputting, from a first rear loudspeaker, the third modified channel signal; and
outputting, from a second rear loudspeaker, the fourth modified channel signal.

### Claim 11 (depends on 1)

A non-transitory computer readable medium storing a computer program that, when executed by a processor, controls an apparatus to execute processing including the method of claim 1.

### Claim 12

An apparatus for rendering audio, the apparatus comprising:
a processor; and
a memory; and
a loudspeaker system comprising a left front loudspeaker, a right front loudspeaker, a left rear loudspeaker and a right rear loudspeaker,
wherein the processor is configured to receive a spatial audio signal, wherein the spatial audio signal includes position information for rendering audio,
wherein the processor is configured to process the spatial audio signal to determine a plurality of weights based on the position information, and
wherein the processor is configured to render the spatial audio signal to form a plurality of rendered signals, wherein the plurality of rendered signals are amplitude weighted according to the plurality of weights, and wherein the plurality of rendered signals includes a plurality of binaural signals that are amplitude weighted according to the plurality of weights,
wherein the left front loudspeaker is configured to output a left channel of a front binaural signal of the plurality of binaural signals, the right front loudspeaker is configured to output a right channel of the front binaural signal, the left rear loudspeaker is configured to output a left channel of a rear binaural signal of the plurality of binaural signals, and the right rear loudspeaker is configured to output a right channel of the rear binaural signal,
wherein the plurality of weights correspond to a front-back perspective applied to the left front loudspeaker and the left rear loudspeaker, and applied to the right front loudspeaker and the right rear loudspeaker.

### Claim 13 (depends on 12)

The apparatus of claim 12, further comprising:
a mounting structure that is adapted to position the left front loudspeaker, the left rear loudspeaker, the right front loudspeaker, and the right rear loudspeaker around a head of a listener.

### Claim 14 (depends on 12)

The apparatus of claim 12, wherein the processor being configured to render the spatial audio signal to form the plurality of rendered signals comprises:
wherein the processor is configured to render the spatial audio signal to generate an interim rendered signal; and
wherein the processor is configured to weight the interim signal according to the plurality of weights to generate the plurality of rendered signals.

### Claim 15 (depends on 12)

The apparatus of claim 12, wherein the processor being configured to render the spatial audio signal to form the plurality of rendered signals corresponds to the processor being configured to split the spatial audio signal, on an amplitude weighting basis, according to the plurality of weights.

### Claim 16 (depends on 12)

The apparatus of claim 12, wherein the spatial audio signal includes a plurality of audio objects,
wherein each of the plurality of audio objects is associated with a respective position of the position information;
wherein the processor being configured to process the spatial audio signal includes wherein the processor is configured to process the plurality of audio objects to extract the position information; and
wherein the plurality of weights correspond to the respective position of each of the plurality of audio objects.