Abstract: Examples of the disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. In an example, a received first input audio signal is processed to generate a left output audio signal and a right output audio signal presented to ears of the user. Processing the first input audio signal comprises applying a delay process to the first input audio signal to generate a left audio signal and a right audio signal; adjusting gains of the left audio signal and the right audio signal; applying head-related transfer functions (HRTFs) to the left and right audio signals to generate the left and right output audio signals. Applying the delay process to the first input audio signal comprises applying an interaural time delay (ITD) to the first input audio signal, the ITD determined based on the source location.

Abstract: Disclosed herein are systems and methods for efficiently rendering audio. A method may include receiving a request to present a first audio track, wherein the first audio track is based on a first audio model comprising a shared model component and a first model component; receiving a request to present a second audio track, wherein the second audio track is based on a second audio model comprising the shared model component and a second model component; rendering a sound based on the first audio track, the second audio track, the shared model component, the first model component, and the second model component; and presenting, via one or more speakers, the an audio signal comprising the rendered sound.

Abstract: An audio system and method of spatially rendering audio signals that uses modified virtual speaker panning is disclosed. The audio system may include a fixed number F of virtual speakers, and the modified virtual speaker panning may dynamically select and use a subset P of the fixed virtual speakers. The subset P of virtual speakers may be selected using a low energy speaker detection and culling method, a source geometry-based culling method, or both. One or more processing blocks in the decoder/virtualizer may be bypassed based on the energy level of the associated audio signal or the location of the sound source relative to the user/listener, respectively. In some embodiments, a virtual speaker that is designated as an active virtual speaker at a first time, may also be designated as an active virtual speaker at a second time to ensure the processing completes.

Abstract: Examples of the disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. In an example, a received first input audio signal is processed to generate a left output audio signal and a right output audio signal presented to ears of the user. Processing the first input audio signal comprises applying a delay process to the first input audio signal to generate a left audio signal and a right audio signal; adjusting gains of the left audio signal and the right audio signal; applying head-related transfer functions (HRTFs) to the left and right audio signals to generate the left and right output audio signals. Applying the delay process to the first input audio signal comprises applying an interaural time delay (ITD) to the first input audio signal, the ITD determined based on the source location.

Abstract: Systems and methods for rendering audio signals are disclosed. In some embodiments, a method may receive an input signal including a first portion and the second portion. A first processing stage comprising a first filter is applied to the first portion to generate a first filtered signal. A second processing stage comprising a second filter is applied to the first portion to generate a second filtered signal. A third processing stage comprising a third filter is applied to the second portion to generate a third filtered signal. A fourth processing stage comprising a fourth filter is applied to the second portion to generate a fourth filtered signal. A first output signal is determined based on a sum of the first filtered signal and the third filtered signal. A second output signal is determined based on a sum of the second filtered signal and the fourth filtered signal.

Abstract: Systems and methods of presenting an output audio signal to a listener located at a first location in a virtual environment are disclosed. According to embodiments of a method, an input audio signal is received. For each sound source of a plurality of sound sources in the virtual environment, a respective first intermediate audio signal corresponding to the input audio signal is determined, based on a location of the respective sound source in the virtual environment, and the respective first intermediate audio signal is associated with a first bus. For each of the sound sources of the plurality of sound sources in the virtual environment, a respective second intermediate audio signal is determined. The respective second intermediate audio signal corresponds to a reflection of the input audio signal in a surface of the virtual environment.

Abstract: An audio system and method of spatially rendering audio signals that uses modified virtual speaker panning is disclosed. The audio system may include a fixed number F of virtual speakers, and the modified virtual speaker panning may dynamically select and use a subset P of the fixed virtual speakers. The subset P of virtual speakers may be selected using a low energy speaker detection and culling method, a source geometry-based culling method, or both. One or more processing blocks in the decoder/virtualizer may be bypassed based on the energy level of the associated audio signal or the location of the sound source relative to the user/listener, respectively. In some embodiments, a virtual speaker that is designated as an active virtual speaker at a first time, may also be designated as an active virtual speaker at a second time to ensure the processing completes.

Abstract: A method of processing an audio signal is disclosed. According to embodiments of the method, magnitude response information of a prototype filter is determined. The magnitude response information includes a plurality of gain values, at least one of which includes a first gain corresponding to a first frequency. The magnitude response information of the prototype filter is stored. The magnitude response information of the prototype filter at the first frequency is retrieved. Gains are computed for a plurality of control frequencies based on the retrieved magnitude response information of the prototype filter at the first frequency, and the computed gains are applied to the audio signal.

Abstract: Examples of the disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. According to an example method, a source location corresponding to the audio signal is identified. For each of the respective left and right ear of the user, a virtual speaker position, of a virtual speaker array, is determined, the virtual speaker position collinear with the source location and with a position of the respective ear. For each of the respective left and right ear of the user, a head-related transfer function (HRTF) corresponding to the virtual speaker position and to the respective ear is determined; and the output audio signal is presented to the respective ear of the user via one or more speakers associated with the wearable head device. Processing the audio signal includes applying the HRTF to the audio signal.

Abstract: Systems and methods of presenting an output audio signal to a listener located at a first location in a virtual environment are disclosed. According to embodiments of a method, an input audio signal is received. A first intermediate audio signal corresponding to the input audio signal is determined, based on a location of the sound source in the virtual environment, and the first intermediate audio signal is associated with a first bus. A second intermediate audio signal is determined. The second intermediate audio signal corresponds to a reverberation of the input audio signal in the virtual environment. The second intermediate audio signal is determined based on a location of the sound source, and further based on an acoustic property of the virtual environment. The second intermediate audio signal is associated with a second bus. The output audio signal is presented to the listener via the first and second buses.

Abstract: Systems and methods of presenting an output audio signal to a listener located at a first location in a virtual environment are disclosed. According to embodiments of a method, an input audio signal is received. For each sound source of a plurality of sound sources in the virtual environment, a respective first intermediate audio signal corresponding to the input audio signal is determined, based on a location of the respective sound source in the virtual environment, and the respective first intermediate audio signal is associated with a first bus. For each of the sound sources of the plurality of sound sources in the virtual environment, a respective second intermediate audio signal is determined. The respective second intermediate audio signal corresponds to a reflection of the input audio signal in a surface of the virtual environment.

Abstract: Systems and methods for rendering audio signals are disclosed. In some embodiments, a method may receive an input signal including a first portion and the second portion. A first processing stage comprising a first filter is applied to the first portion to generate a first filtered signal. A second processing stage comprising a second filter is applied to the first portion to generate a second filtered signal. A third processing stage comprising a third filter is applied to the second portion to generate a third filtered signal. A fourth processing stage comprising a fourth filter is applied to the second portion to generate a fourth filtered signal. A first output signal is determined based on a sum of the first filtered signal and the third filtered signal. A second output signal is determined based on a sum of the second filtered signal and the fourth filtered signal.

Abstract: Examples of the disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. According to an example method, a source location corresponding to the audio signal is identified. For each of the respective left and right ear of the user, a virtual speaker position, of a virtual speaker array, is determined, the virtual speaker position collinear with the source location and with a position of the respective ear. For each of the respective left and right ear of the user, a head-related transfer function (HRTF) corresponding to the virtual speaker position and to the respective ear is determined; and the output audio signal is presented to the respective ear of the user via one or more speakers associated with the wearable head device. Processing the audio signal includes applying the HRTF to the audio signal.

Abstract: Systems and methods of presenting an output audio signal to a listener located at a first location in a virtual environment are disclosed. According to embodiments of a method, an input audio signal is received. A first intermediate audio signal corresponding to the input audio signal is determined, based on a location of the sound source in the virtual environment, and the first intermediate audio signal is associated with a first bus. A second intermediate audio signal is determined. The second intermediate audio signal corresponds to a reverberation of the input audio signal in the virtual environment. The second intermediate audio signal is determined based on a location of the sound source, and further based on an acoustic property of the virtual environment. The second intermediate audio signal is associated with a second bus. The output audio signal is presented to the listener via the first and second buses.

Abstract: Systems and methods for providing accurate and independent control of reverberation properties are disclosed. In some embodiments, a system may include a reverberation processing system, a direct processing system, and a combiner. The reverberation processing system can include a reverb initial power (RIP) control system and a reverberator. The RIP control system can include a reverb initial gain (RIG) and a RIP corrector. The RIG can be configured to apply a RIG value to the input signal, and the RIP corrector can be configured to apply a RIP correction factor to the signal from the RIG. The reverberator can be configured to apply reverberation effects to the signal from the RIP control system. In some embodiments, one or more values and/or correction factors can be calculated and applied such that the signal output from a component in the reverberation processing system is normalized to a predetermined value (e.g., unity (1.0)).

Abstract: Disclosed herein are systems and methods for storing, organizing, and maintaining acoustic data for mixed reality systems. A system may include one or more sensors of a head-wearable device, a speaker of the head-wearable device, and one or more processors. A method performed by the one or more processors may include receiving a request to present an audio signal. An environment may be identified via the one or more sensors of the head-wearable device. One or more audio model components associated with the environment may be retrieved. A first audio model may be generated based on the audio model components. A second audio model may be generated based on the first audio model. A modified audio signal may be determined based on the second audio model and based on the request to present an audio signal. The modified audio signal may be presented via the speaker of the head-wearable device.

Abstract: Examples of the disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. According to an example method, a first input audio signal is received. The first input audio signal is processed to generate a first output audio signal. The first output audio signal is presented via one or more speakers associated with the wearable head device. Processing the first input audio signal comprises applying a pre-emphasis filter to the first input audio signal; adjusting a gain of the first input audio signal; and applying a de-emphasis filter to the first audio signal. Applying the pre-emphasis filter to the first input audio signal comprises attenuating a low frequency component of the first input audio signal. Applying the de-emphasis filter to the first input audio signal comprises attenuating a high frequency component of the first input audio signal.

Abstract: A method of processing an audio signal is disclosed. According to embodiments of the method, magnitude response information of a prototype filter is determined. The magnitude response information includes a plurality of gain values, at least one of which includes a first gain corresponding to a first frequency. The magnitude response information of the prototype filter is stored. The magnitude response information of the prototype filter at the first frequency is retrieved. Gains are computed for a plurality of control frequencies based on the retrieved magnitude response information of the prototype filter at the first frequency, and the computed gains are applied to the audio signal.

Abstract: Examples of the disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. In an example, a received first input audio signal is processed to generate a left output audio signal and a right output audio signal presented to ears of the user. Processing the first input audio signal comprises applying a delay process to the first input audio signal to generate a left audio signal and a right audio signal; adjusting gains of the left audio signal and the right audio signal; applying head-related transfer functions (HRTFs) to the left and right audio signals to generate the left and right output audio signals. Applying the delay process to the first input audio signal comprises applying an interaural time delay (ITD) to the first input audio signal, the ITD determined based on the source location.

Abstract: Systems and methods for providing accurate and independent control of reverberation properties are disclosed. In some embodiments, a system may include a reverberation processing system, a direct processing system, and a combiner. The reverberation processing system can include a reverb initial power (RIP) control system and a reverberator. The RIP control system can include a reverb initial gain (RIG) and a RIP corrector. The RIG can be configured to apply a RIG value to the input signal, and the RIP corrector can be configured to apply a RIP correction factor to the signal from the RIG. The reverberator can be configured to apply reverberation effects to the signal from the RIP control system. In some embodiments, one or more values and/or correction factors can be calculated and applied such that the signal output from a component in the reverberation processing system is normalized to a predetermined value (e.g., unity (1.0)).