Reflected sound rendering for object-based audio
Embodiments are described for rendering spatial audio content through a system that is configured to reflect audio off of one or more surfaces of a listening environment. The system includes an array of audio drivers distributed around a room, wherein at least one driver of the array of drivers is configured to project sound waves toward one or more surfaces of the listening environment for reflection to a listening area within the listening environment and a renderer configured to receive and process audio streams and one or more metadata sets that are associated with each of the audio streams and that specify a playback location in the listening environment.
1. A system for rendering sound using reflected sound elements, comprising:
an array of audio drivers for distribution around a listening environment, wherein at least one driver of the array of audio drivers is an upward-firing driver, which is configured to project sound waves toward a ceiling of the listening environment for reflection to a listening area within the listening environment;
a renderer configured to receive and process a bitstream including audio streams and one or more metadata sets that are associated with each of the audio streams and that specify a playback location in the listening environment of audio objects in a respective audio stream, wherein the audio streams comprise one or more reflected audio streams and one or more direct audio streams, the renderer further configured to render one or more of the audio objects that should be rendered above a head of a listener at the listening area in the listening environment using an upward-firing driver and height information related to the one or more audio objects; and
a playback component coupled to the renderer and configured to render the audio streams to a plurality of audio feeds corresponding to the array of audio drivers in accordance with the one or more metadata sets, and wherein the one or more reflected audio streams are transmitted to the at least one upward-firing driver; characterized in that the system performs signal processing to introduce perceptual height cues into the reflected audio streams fed to the at least one upward-firing driver, the perceptual height cues derived by at least partially removing from the reflected audio streams a first height cue for a physical speaker location in the listening environment and at least partially inserting in the reflected audio streams a second height cue for a reflected speaker location.
2. The system of claim 1 wherein each audio driver of the array of audio drivers is uniquely addressable according to a communication protocol used by the renderer and the playback component.
3. The system of claim 2 wherein the at least one audio driver comprises one of: a side-firing driver and an upward-firing driver, and wherein the at least one audio driver is further embodied in one of: a standalone driver within a speaker enclosure and a driver placed proximate one or more front firing drivers in a unitary speaker enclosure.
4. The system of claim 3 wherein the array of audio drivers comprises drivers that are distributed around the listening environment in accordance with a defined surround sound configuration.
5. The system of claim 4 wherein the listening environment comprises a home environment, and wherein the renderer and playback component comprise part of a home audio system, and further wherein the audio streams comprise audio content that includes at least one of cinema content transformed for playback in the home environment, television content, user generated content, computer game content, or music.
6. The system of claim 4 wherein a metadata set associated with the audio stream transmitted to the at least one driver defines one or more characteristics pertaining to the reflection.
7. The system of claim 6 wherein the metadata set supplements a base metadata set that includes metadata elements associated with an object-based stream of spatial audio information, and wherein the metadata elements for the object-based stream specify spatial parameters that control the playback of a corresponding object-based sound and comprise at least one of sound position, sound width, or sound velocity.
8. The system of claim 7 wherein the metadata set further includes metadata elements associated with a channel-based stream of the spatial audio information, and wherein the metadata elements associated with each channel-based stream comprise designations of surround-sound channels of the audio drivers in the defined surround-sound configuration.
9. The system of claim 6 wherein the at least one driver is associated with a microphone placed in the listening environment, the microphone configured to transmit configuration audio information encapsulating characteristics of the listening environment to a calibration component coupled to the renderer, and wherein the configuration audio information is used by the renderer to define or modify the metadata set associated with the audio stream transmitted to the at least one audio driver.
10. The system of claim 1 wherein the at least one driver comprises one of: a manually adjustable audio transducer within an enclosure that is adjustable with respect to a sound firing angle relative to a floor plane of the listening environment and an electrically controllable audio transducer within an enclosure that is automatically adjustable with respect to the sound firing angle.