Abstract: A method of presenting an audio signal to a user of a mixed reality environment is disclosed. According to examples of the method, an audio event associated with the mixed reality environment is detected. The audio event is associated with a first audio signal. A location of the user with respect to the mixed reality environment is determined. An acoustic region associated with the location of the user is identified. A first acoustic parameter associated with the first acoustic region is determined. A transfer function is determined using the first acoustic parameter. The transfer function is applied to the first audio signal to produce a second audio signal, which is then presented to the user.

Abstract: Disclosed herein are systems and methods for processing speech signals in mixed reality applications. A method may include receiving an audio signal; determining, via first processors, whether the audio signal comprises a voice onset event; in accordance with a determination that the audio signal comprises the voice onset event: waking a second one or more processors; determining, via the second processors, that the audio signal comprises a predetermined trigger signal; in accordance with a determination that the audio signal comprises the predetermined trigger signal: waking third processors; performing, via the third processors, automatic speech recognition based on the audio signal; and in accordance with a determination that the audio signal does not comprise the predetermined trigger signal: forgoing waking the third processors; and in accordance with a determination that the audio signal does not comprise the voice onset event: forgoing waking the second processors.

Abstract: A method of presenting an audio signal to a user of a mixed reality environment is disclosed. According to examples of the method, an audio event associated with the mixed reality environment is detected. The audio event is associated with a first audio signal. A location of the user with respect to the mixed reality environment is determined. An acoustic region associated with the location of the user is identified. A first acoustic parameter associated with the first acoustic region is determined. A transfer function is determined using the first acoustic parameter. The transfer function is applied to the first audio signal to produce a second audio signal, which is then presented to the user.

Abstract: Disclosed herein are systems and methods for presenting audio content in mixed reality environments. A method may include receiving a first input from an application program; in response to receiving the first input, receiving, via a first service, an encoded audio stream; generating, via the first service, a decoded audio stream based on the encoded audio stream; receiving, via a second service, the decoded audio stream; receiving a second input from one or more sensors of a wearable head device; receiving, via the second service, a third input from the application program, wherein the third input corresponds to a position of one or more virtual speakers; generating, via the second service, a spatialized audio stream based on the decoded audio stream, the second input, and the third input; presenting, via one or more speakers of the wearable head device, the spatialized audio stream.

Abstract: A method of presenting an audio signal to a user of a mixed reality environment is disclosed, the method comprising the steps of detecting a first audio signal in the mixed reality environment, where the first audio signal is a real audio signal; identifying a virtual object intersected by the first audio signal in the mixed reality environment; identifying a listener coordinate associated with the user; determining, using the virtual object and the listener coordinate, a transfer function; applying the transfer function to the first audio signal to produce a second audio signal; and presenting, to the user, the second audio signal.

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: In some embodiments, a first audio signal is received via a first microphone, and a first probability of voice activity is determined based on the first audio signal. A second audio signal is received via a second microphone, and a second probability of voice activity is determined based on the first and second audio signals. Whether a first threshold of voice activity is met is determined based on the first and second probabilities of voice activity. In accordance with a determination that a first threshold of voice activity is met, it is determined that a voice onset has occurred, and an alert is transmitted to a processor based on the determination that the voice onset has occurred. In accordance with a determination that a first threshold of voice activity is not met, it is not determined that a voice onset has occurred.

Abstract: Examples of the disclosure describe systems and methods for estimating acoustic properties of an environment. In an example method, a first audio signal is received via a microphone of a wearable head device. An envelope of the first audio signal is determined, and a first reverberation time is estimated based on the envelope of the first audio signal. A difference between the first reverberation time and a second reverberation time is determined. A change in the environment is determined based on the difference between the first reverberation time and the second reverberation time. A second audio signal is presented via a speaker of a wearable head device, wherein the second audio signal is based on the second reverberation time.

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: Disclosed herein are systems and methods for presenting audio content in mixed reality environments. A method may include receiving a first input from an application program; in response to receiving the first input, receiving, via a first service, an encoded audio stream; generating, via the first service, a decoded audio stream based on the encoded audio stream; receiving, via a second service, the decoded audio stream; receiving a second input from one or more sensors of a wearable head device; receiving, via the second service, a third input from the application program, wherein the third input corresponds to a position of one or more virtual speakers; generating, via the second service, a spatialized audio stream based on the decoded audio stream, the second input, and the third input; presenting, via one or more speakers of the wearable head device, the spatialized audio stream.

Abstract: A method of presenting an audio signal to a user of a mixed reality environment is disclosed, the method comprising the steps of detecting a first audio signal in the mixed reality environment, where the first audio signal is a real audio signal; identifying a virtual object intersected by the first audio signal in the mixed reality environment; identifying a listener coordinate associated with the user; determining, using the virtual object and the listener coordinate, a transfer function; applying the transfer function to the first audio signal to produce a second audio signal; and presenting, to the user, the second 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. 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: In some embodiments, a first audio signal is received via a first microphone, and a first probability of voice activity is determined based on the first audio signal. A second audio signal is received via a second microphone, and a second probability of voice activity is determined based on the first and second audio signals. Whether a first threshold of voice activity is met is determined based on the first and second probabilities of voice activity. In accordance with a determination that a first threshold of voice activity is met, it is determined that a voice onset has occurred, and an alert is transmitted to a processor based on the determination that the voice onset has occurred. In accordance with a determination that a first threshold of voice activity is not met, it is not determined that a voice onset has occurred.

Abstract: Examples of the disclosure describe systems and methods for estimating acoustic properties of an environment. In an example method, a first audio signal is received via a microphone of a wearable head device. An envelope of the first audio signal is determined, and a first reverberation time is estimated based on the envelope of the first audio signal. A difference between the first reverberation time and a second reverberation time is determined. A change in the environment is determined based on the difference between the first reverberation time and the second reverberation time. A second audio signal is presented via a speaker of a wearable head device, wherein the second audio signal is based on the second reverberation time.

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 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. 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.