Audio adaptation for the room

Abstract

The present disclosure relates to audio adaptation of a room. An audio system includes one or more speaker enclosures, each having a speaker. Sensing logic determines the acoustic environment of the speaker enclosure. The sensing logic may include an echo canceller. A low-pass filter corrects an audio program based on the acoustic environment of the speaker enclosure. The system outputs an omnidirectional sound pattern that may be a low-frequency sound to determine the acoustic environment. If the acoustic environment is in free space, the system may generate a directional pattern superimposed on the omnidirectional pattern. If the acoustic environment is not in free space, the system may direct ambient content towards a wall and direct content away from the wall. The sensing logic automatically determines the acoustic environment upon initial power-up and upon detecting a change in the position of the speaker enclosure. An accelerometer may detect a change in the position of the speaker enclosure.

Description

[0001] This application is a divisional application of the invention patent application with the application number 201810543241.9, the application date of May 31, 2018, and the invention title of "Audio Adaptation for a Room". Technical Field

[0002] Embodiments of the present invention relate to the field of speaker rendering of audio; more specifically, to audio rendering with environmental compensation. Background Art

[0003] It is desirable to reproduce a sound recording such that it sounds as natural as in the original recording environment. The method is to create a sound field around the listener with a spatial distribution that more closely approximates the spatial distribution of the original recording environment. Early experiments in this field have revealed, for example, that by outputting a music signal through a speaker in front of the listener and outputting a slightly delayed version of the same signal through a speaker behind the listener, the listener is given the feeling that they are in a large room and the music is being played in front of them. The arrangement can be improved by adding another speaker on the left side of the listener and another speaker on the right side, and feeding the same signal to these side speakers with a delay different from the delay between the front and rear speakers. However, using multiple speakers increases the cost and complexity of the audio system.

[0004] Speaker reproduction is affected by nearby obstacles such as walls. Such acoustic boundaries produce reflections of the sound emitted by the speaker. The reflections can enhance or degrade the sound. The effect of the reflections can vary according to the frequency of the sound. Lower frequencies (especially those below about 400 Hz) can be particularly susceptible to reflections from acoustic boundaries.

[0005] There is a desire to provide an easier and more effective way to provide natural sound reproduction of a sound recording with fewer speakers. Summary of the Invention

[0006] An audio system includes one or more speaker enclosures, each having a speaker. Sensing logic determines the acoustic environment of the speaker enclosure. The sensing logic may include an echo canceller. A low-pass filter corrects an audio program based on the acoustic environment of the speaker enclosure. The system output can be an omnidirectional sound pattern for low-frequency sounds to determine the acoustic environment. If the acoustic environment is in free space, the system can generate a directional pattern superimposed on the omnidirectional pattern. If the acoustic environment is not in free space, the system can direct the environmental content towards the wall and the direct content away from the wall. The sensing logic automatically determines the acoustic environment upon initial power-up and upon detecting a change in the position of the speaker enclosure. An accelerometer can detect a change in the position of the speaker enclosure.

[0007] Other features and advantages of the present invention will be apparent from the drawings and from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present invention may be best understood by reference to the following description and drawings, which are used to illustrate embodiments of the present invention by way of example and not limitation. In the figures, like reference numerals indicate like elements:

[0009] Figure 1 is a block diagram of a first audio system embodying the present invention.

[0010] Figure 2 is a block diagram of a second audio system embodying the present invention.

[0011] Figure 3 is a block diagram of a third audio system embodying the present invention.

[0012] Figure 4 is a block diagram of a fourth audio system embodying the present invention. DETAILED DESCRIPTION

[0013] The following description sets forth numerous specific details. However, it should be understood that embodiments of the present invention may be practiced without these specific details. In other instances, well-known circuits, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description.

[0014] In the following description, reference is made to the drawings which illustrate several embodiments of the present invention. It should be understood that other embodiments may be utilized and mechanical, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description should not be taken in a limiting sense, and the scope of embodiments of the present invention is defined only by the claims of the issued patent.

[0015] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. Spatially relative terms, such as "beneath," "below," "lower," "above," "upper," etc., may be used herein for convenience in describing one element or feature's relationship to another or other elements or features as illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element described as "beneath" or "below" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "beneath" can encompass both an orientation of above and below. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein are to be interpreted accordingly.

[0016] As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms "comprises" and / or "comprising" specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or their groups.

[0017] The term "or" as well as "and / or" used herein shall be interpreted inclusively or mean any one or any combination. Thus, "A, B, or C" or "A, B, and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B, and C." An exception to this definition occurs only when the combination of elements, functions, steps, or acts is inherently mutually exclusive in some way.

[0018] Figure 1 is a view of an exemplary audio system. The audio system includes a speaker enclosure 100 having a speaker driver 102 integrated therein. An audio amplifier 114 is provided and is coupled to an input of the speaker driver 102. A sensing logic component 108 determines the acoustic environment of the speaker enclosure 100, as further described below. A low-frequency correction filter 112 receives an audio program 110 and generates an audio signal that corrects the audio program for room effects based on the acoustic environment of the speaker enclosure 100, as further described below. The audio signal is provided to the audio amplifier 114 to output the corrected audio program through the speaker driver 102 in the speaker enclosure 100.

[0019] The sensing logic component and the low-frequency correction filter may use the techniques disclosed in U.S. Patent Application No. 14 / 989,727, filed on January 6, 2016, and titled LOUDSPEAKER EQUALIZER, which is hereby incorporated by reference in its entirety.

[0020] Figure 2 is a view of another exemplary audio system. The audio system includes a speaker enclosure 200 having nine speaker drivers integrated therein, one driver 202 facing upward and two drivers 204 facing outward on each of the four sides of the speaker enclosure.

[0021] Nine audio amplifiers 214 each provide an output coupled to an input of one of the nine speaker drivers 202, 204. One audio amplifier is associated with each speaker driver. For clarity of illustration, only one of these audio amplifiers is shown, and the signal connections between the audio amplifiers and the speaker drivers are omitted. Additional audio amplifiers and their connections to the speaker drivers are implied by ellipses.

[0022] The sensing logic component 208 determines the acoustic environment of the speaker enclosure 200, as described below. One or more low-frequency correction filters 212 receive the audio program 210 and generate an audio signal that corrects the audio program for room effects based on the acoustic environment of the speaker enclosure 200, as described below. The low-frequency correction filters 212 may be provided for each driver 202, 204 in the speaker enclosure 200 or only for some drivers (such as those providing low-frequency output, e.g., woofers and / or subwoofers). For clarity, additional low-frequency correction filters and their connections to the audio amplifiers are implied by ellipses.

[0023] Figure 3 is a view of another exemplary audio system. The audio system includes two speaker enclosures 300A, 300B, with seven speaker drivers integrated therein, one driver 302 facing upward, and three drivers 304 facing outward on each of the front-facing and rear-facing sides of the speaker enclosures. Although two speaker enclosures are shown, it should be understood that a greater number of speaker enclosures may be used in other audio systems embodying the present invention.

[0024] Seven audio amplifiers 314 each provide an output coupled to an input of one of the seven speaker drivers. One audio amplifier is associated with each speaker driver. For clarity of illustration, only one of these audio amplifiers is shown, and the signal connections between the audio amplifiers and the speaker drivers are omitted.

[0025] The sensing logic component 308 determines the acoustic environment of each of the speaker enclosures 300A, 300B, as described below. Two or more low-frequency correction filters 312 each receive a channel of the audio program 310 and generate an audio signal that corrects the channel of the audio program for room effects based on the acoustic environment of each of the speaker enclosures 300A, 300B, as described below. The low-frequency correction filters 312 may be provided for each driver 302, 304 in each of the speaker enclosures 300A, 300B or only for some drivers (such as those providing low-frequency output, e.g., woofers and / or subwoofers). The low-frequency correction filters may be provided for drivers in some (but not all) of the speaker enclosures in an audio system embodying the present invention.

[0026] It should be understood that an audio system including two or more speaker enclosures may have one or more speaker drivers arranged in various configurations, such as Figure 1 and Figure 2 the configurations shown. Similarly, Figure 1 the arrangements of the speaker drivers shown can be used in an audio system including one speaker enclosure. Other speaker driver arrangements other than those illustrated may be used in practicing the audio system of the present invention.

[0027] The audio system practicing the present invention includes sensing logic for determining the acoustic environment of the speaker drivers in the speaker enclosure. It should be understood that the performance of a speaker driver is affected by acoustic obstacles (such as walls) that can reflect and / or absorb the sound being output by the speaker driver. The acoustic properties of the acoustic obstacles can be frequency-dependent. Reflection can reinforce or cancel the sound generated by the speaker driver, depending on the position of the reflective acoustic surface and the frequency of the sound.

[0028] Figure 4 is a view of another exemplary audio system. The audio system includes a cylindrical speaker enclosure 400 in which eight speaker drivers 404 are integrated, each of these drivers facing outward from the speaker enclosure. It should be understood that other embodiments of the system may use other cylindrically-shaped speaker enclosures, such as octagonal or other regular polygons, the system may use more or fewer than eight speaker drivers, and the system may have drivers facing upward, similar to the drivers disclosed in the previous embodiments.

[0029] Eight audio amplifiers 414 each provide an output coupled to an input of one of the eight speaker drivers 404. One audio amplifier is associated with each speaker driver. For clarity of illustration, only one of these audio amplifiers is shown, and the signal connections between the audio amplifiers and the speaker drivers are omitted. The additional audio amplifiers and their connections to the speaker drivers are implied by ellipses.

[0030] The sensing logic 408 determines the acoustic environment of the speaker enclosure 400, as described below. The playback mode processor receives an audio program 410 and generates an audio signal that adjusts the audio program for room effects based on the acoustic environment of the speaker enclosure 400 (as described below), adjusts the audio program in response to the acoustic environment of each of the one or more speaker enclosures, and provides the one or more audio signals to the one or more audio amplifiers to output the corrected audio program through the one or more speaker drivers in each of the one or more speaker enclosures.

[0031] Referring again to Figure 1, the sensing logic component 108 can generate an acoustic pattern and provide the acoustic pattern to the audio amplifier 114. The acoustic pattern can be an omnidirectional acoustic pattern, a highly directional acoustic pattern, or another acoustic pattern that affects low or high audio frequencies. The acoustic pattern is output through the speaker driver 102 in the speaker enclosure 100 to determine the acoustic environment of the speaker enclosure. In other embodiments where the speaker enclosure includes two or more speaker drivers, the acoustic pattern can be output through a single speaker driver in the speaker enclosure or through some or all of the speaker drivers in the speaker enclosure. In other embodiments where there are two or more speaker enclosures, the acoustic pattern can be sequentially output through the speaker drivers in each of these speaker enclosures to sequentially determine the acoustic environment of each of these speaker enclosures.

[0032] The sensing logic component 108 partially operates on information related to the signals received on the microphone 118, which are the sounds at the outer boundary of the speaker enclosure 100 in response to those generated by the respective speakers 102 and can be estimated by the microphone 116 inside the speaker enclosure. The sensing logic component 108 does this by, for example, examining the transfer function measurements between the microphones 116, 118 and between the speaker 102 and the microphone 118. The sensing logic component 108 can receive signals from the external microphone 118, which can be located on the outer surface of the speaker enclosure 100 or placed to detect the sound pressure level near the outer surface. For the purposes of this patent application, the phrases "external microphone" and "microphone outside the speaker enclosure" refer to a microphone placed such that it generates a signal in response to the sound pressure level near the outer surface of the speaker enclosure.

[0033] The sensing logic component 108 compares the signals from the external microphone 118 with the signals indicating the amount of acoustic energy being output by the speaker driver 102. The indication of the driver output acoustic energy can be provided by the internal microphone 116. In other embodiments, the indication of the driver output acoustic energy can be provided by an optical system that measures the displacement of the speaker cone of the speaker driver or by an electrical system that derives the indication of the driver output acoustic energy from the electrical energy being provided to the speaker driver.

[0034] The sensing logic component 108 estimates the acoustic path between the speaker driver 102 in the speaker enclosure 100 and the microphone 118 outside the speaker enclosure. The sensing logic component 108 can include an echo canceller for estimating the acoustic path between the speaker driver 102 and the microphone 118.

[0035] The sensing logic component can use other techniques to estimate the acoustic path between the speaker driver and the microphone, such as the techniques disclosed in U.S. Patent Application 14 / 920,611, titled ENVIRONMENT SENSING USING COUPLED MICROPHONES AND LOUDSPEAKERS AND NOMINAL PLAYBACK, filed on October 22, 2015, which is hereby incorporated by reference in its entirety.

[0036] The sensing logic component 108 can classify the acoustic environment of the speaker enclosure as being in free space, where there are no acoustic obstacles or boundaries close enough to the speaker enclosure to significantly affect the sound generated by the speaker driver in the speaker enclosure. For the purposes of this patent application, the phrase "significantly affect the sound" means changing the sound to the extent that it would be perceptible to a listener without using a measuring device. It can be assumed that the speaker enclosure is designed to be supported on a surface in such a way that the effect of the support surface is part of the intended sound. Thus, the support surface may not be considered an acoustic obstacle or boundary. The speaker enclosure is in free space if it is far enough away from all walls and large furniture to avoid significant acoustic reflections from such obstacles.

[0037] When there are acoustic obstacles or boundaries close enough to the speaker enclosure to significantly affect the sound generated by the speaker driver in the speaker enclosure, i.e., when the speaker enclosure is not in free space, the sensing logic component 108 can further classify the acoustic environment of the speaker enclosure. The further classification can be based on the typical placement of the speaker enclosure. For example, if there is a single reflective acoustic surface near the speaker enclosure, the acoustic environment can be further classified as near a wall. If there are two reflective acoustic surfaces that are perpendicular to each other near the speaker enclosure, the acoustic environment can be further classified as in a corner. If there are three reflective acoustic surfaces that are perpendicular to each other near the speaker enclosure and one acoustic surface is parallel to the support surface of the speaker enclosure, the acoustic environment can be further classified as in a bookshelf.

[0038] Referring again to Figure 2 , the audio system can provide a playback mode processor 220 for receiving an audio program and adjusting the audio program according to a playback mode determined by the acoustic environment of the audio system. An audio system that provides a playback mode processor will typically include one or more speaker enclosures, each of which includes more than one speaker driver.

[0039] The playback mode processor 220 adjusts portions of the audio program 210 directed to the speaker enclosure 200 to affect the manner in which the audio program is output by the plurality of speaker drivers 202, 204 in the speaker enclosure. The playback mode processor 220 will have a plurality of outputs for the plurality of speaker drivers, as implied by the ellipsis for clarity. If used for a particular driver, the low-frequency correction filter 212 may be placed before or after the playback mode processor 220.

[0040] The playback mode processor 220 may adjust the audio program 210 to output portions of the audio program from the speaker enclosure 200 in a particular direction. The sound output direction may be controlled by directing portions of the audio program to speaker drivers oriented in the desired direction. Some speaker enclosures may include speaker drivers arranged as a speaker array. The playback mode processor may control the sound output direction by causing the speaker array to emit a beamformed sound pattern in the desired direction.

[0041] If the acoustic environment is in free space, the playback mode processor 220 may adjust the audio program 210 such that the speaker drivers 202, 204 generate a directional pattern superimposed on an omnidirectional pattern. The directional pattern may include portions of the audio program 210 that are spatially localized in the sound field, such as portions unique to the left or right channel. The directional pattern may be limited to the higher frequency portions of the audio program 210, such as portions above 400 Hz, which listeners may more specifically spatially localize. The omnidirectional pattern may include portions of the audio program 210 that are heard throughout the sound field, such as portions common to both the left and right channels. The omnidirectional pattern may include the lower frequency portions of the audio program 210, such as portions below 400 Hz, which are difficult for listeners to spatially localize.

[0042] If the acoustic environment is not in free space, the playback mode processor 220 may adjust the audio program 210 such that the speaker drivers 202, 204 direct the ambient content of the audio program toward the wall and direct the direct content of the audio program away from the wall.

[0043] If the acoustic environment is classified as being in a bookshelf, the playback mode processor 220 may adjust the audio program 210 such that the speaker drivers 202, 204 form a highly directional beam pointing away from the bookshelf.

[0044] The playback mode processor may adjust the audio program using the techniques described in U.S. Patent Application No. 15 / 593,887, titled "SPATIAL AUDIO RENDERING STRATEGIES FOR BEAMFORMING LOUDSPEAKER ARRAY," filed on May 12, 2017, which is hereby incorporated by reference in its entirety. The playback mode processor may use the techniques described in U.S. Patent Application No. 15 / 275,312, titled "CONSTRAINED LEAST-SQUARES AMBIENCE EXTRACTION FROM STEREO SIGNALS," filed on September 23, 2016, to separate the ambient content of the audio program from the direct content, which is hereby incorporated by reference in its entirety.

[0045] The sensing logic component 208 may implicitly assume which signals and sound sources are dominant in the respective speakers and microphones when the sensing logic component 208 uses such metrics. Additionally, in practice, there must be sufficient signal levels present during operation, above internal device and ambient noise, to allow for effective measurement and analysis. Such levels and transfer functions, as well as the assumptions of their estimation, may be required in various frequency bands, during various time intervals, or during various "modes" of device operation.

[0046] Outside of a laboratory or controlled setting, in the actual deployment of the device, it is necessary to ensure that the sensing logic component 208 algorithm operates under such valid assumptions as are necessary for a particular sensing logic component operation and decision. To help ensure that the sensing logic component 208 is operating with valid inputs, the sensing logic component may include a "supervisory" logic component.

[0047] The supervisory logic component, in its simplest form, accepts various signals and makes absolute and relative signal level measurements and comparisons. Specifically, the supervisory logic component examines these measurements and comparisons against various targets and adjusted assumptions, which constitute tests, and flags problems whenever one or more of the tests / assumptions are violated. Before making sensing logic component decisions and changes, the supervisory logic component may detect such flags to examine the status of the various tests. The flags may also optionally drive or gate individual "estimators" in the sensing logic component, thereby warning them that required assumptions or conditions are being violated.

[0048] The monitoring logic component is designed to be flexible as it can be adjusted to examine one or more user-defined frequency bands, it can accept one or more microphone signals, and it can be adjusted by the user with various absolute and relative signal level targets. The monitoring logic component can have modes in which one or more tests are either included or excluded, depending on the scenario of what the sensing logic component needs this particular monitoring logic component to do.

[0049] The monitoring logic component adapts to real audio signals, which are quite dynamic in time and frequency. This is especially true for music and conversations. The "level" target can be dynamic to adapt to the real audio signal. The "level" target can be a statistical target. The monitoring logic component can collect specific types of measurements over short time intervals that can be user-defined (e.g., intervals of tens to hundreds of milliseconds), and accumulate multiple such measurements over long time intervals that can also be user-defined (e.g., intervals on the order of hundreds of milliseconds to seconds). The target for this type of measurement is then defined by a target level and a ratio, where the "short" measurements collected over the defined "long" interval that meet the target level must exceed the defined ratio in order to pass the test. Setting such levels and ratios can involve the frequency bands of interest and the expected signal types.

[0050] The sensing logic component 208 can collect multiple measurements from each microphone used by the sensing logic component during a first time period. Each of these measurements is taken over a second time period that is shorter than the first time period. The sensing logic component 208 compares each of these measurements with a target level to determine the ratio of these measurements that meet the target level. The second time period can be between 10 milliseconds and 500 milliseconds, while the first time period can be at least ten times the second time period.

[0051] If the ratio of the multiple measurements that meet the target level is below a threshold, the sensing logic component 208 can disable the application of the low-frequency correction filter 212 and the determination of the acoustic environment of the audio system.

[0052] The sensing logic component 208 can automatically determine the acoustic environment of the audio system when the audio system is initially powered on, without any intervention by the user on the audio system. The sensing logic component 208 can further detect when the acoustic environment of the speaker enclosure changes and automatically re-determine the acoustic environment of the audio system, again without any intervention by the user on the audio system. The acoustic environment can be changed by moving the speaker enclosure or by placing an acoustic obstacle near the speaker enclosure. The change in the acoustic environment of the speaker enclosure can be detected by a change in the audio characteristics.

[0053] In some embodiments, the accelerometer 222 is coupled to the speaker enclosure 200 to detect changes in the position of the speaker enclosure. This can allow for more rapid detection of position changes.

[0054] The sensing logic 208 may utilize the techniques described in U.S. Patent Application No. 15 / 611,083, titled ACOUSTIC CHANGE DETECTION, filed on June 1, 2017, which is hereby incorporated by reference in its entirety.

[0055] If a change in the acoustic environment of the speaker enclosure is detected, the sensing logic 208 may fallback to an omnidirectional mode and initiate a calibration procedure. The recalibration is generally transparent to the user. The user may hear some optimization, but nothing is obvious.

[0056] The low-frequency correction filter 212 and / or the playback mode processor 220 may respond to the re-determined acoustic environment after the speaker enclosure has been moved.

[0057] Referring again Figure 3 , in some embodiments, the audio system includes two or more speaker enclosures 302A, 302B. In such embodiments, the playback processor 320 may adjust the audio program 310 to utilize the multiple speaker enclosures 302A, 302B.

[0058] For example, if the acoustic environment is in free space, the playback mode processor 320 may adjust the audio program 310 such that the speaker drivers 302, 304 generate a directional pattern superimposed on an omnidirectional pattern. The omnidirectional pattern may be the same for both speaker enclosures 302A, 302B, while the directional pattern is specific to each speaker enclosure. The directional patterns may be directed to complement each other, such as by directing the patterns to deviate from each other to some extent to provide a more extended sound.

[0059] As another example, if the acoustic environment is not in free space, the playback mode processor 320 may adjust the audio program 310 such that the speaker drivers 202, 204 direct the ambient content of the audio program towards the wall and the direct content of the audio program away from the wall. If there are multiple speaker enclosures 302A, 302B, the ambient content may be separated to place the ambient content according to the positions of the speaker enclosures. For example, for two speaker enclosures 302A, 302B, the ambient content may be divided into left ambient and right ambient and sent to the left speaker enclosure and the right speaker enclosure, respectively. The direct content may be similarly directed to the appropriately positioned speaker enclosures.

[0060] The playback mode processor utilizes the technology disclosed in U.S. Patent Application No. 15 / 311,824, titled USING THE LOCATION OF AN EAR-END USER IN A VIDEO STREAM TO ADJUST AUDIO SETTINGS OF A FAR-END SYSTEM, filed on November 16, 2016, which is hereby incorporated by reference in its entirety.

[0061] Referring again Figure 4 , the audio system may provide a playback mode processor 420 for receiving an audio program 410 and adjusting the audio program according to a playback mode determined by the acoustic environment of the audio system. As described above for the Figure 2 system shown, the playback mode processor 420 adjusts the portion of the audio program 410 that is directed to the speaker enclosure 400 to affect the manner in which the audio program is output by the plurality of speaker drivers 404 in the speaker enclosure. The playback mode processor 420 will have a plurality of outputs for the plurality of speaker drivers, as implied by the ellipsis for clarity.

[0062] The playback mode processor 420 may adjust the audio program 410 to output a portion of the audio program from the speaker enclosure 400 in a specific direction. The sound output direction may be controlled by directing a portion of the audio program to a speaker driver oriented in the desired direction.

[0063] If the acoustic environment is in free space, the playback mode processor 420 may adjust the audio program 410 such that the speaker drivers 402, 404 generate a directional pattern superimposed on an omnidirectional pattern. The directional pattern may include portions of the audio program 410 that are spatially located in the sound field, such as portions unique to the left or right channels. The directional pattern may be limited to the higher frequency portions of the audio program 410, such as portions above 400 Hz, which listeners may be able to more specifically spatially locate. The omnidirectional pattern may include portions of the audio program 410 that are heard throughout the sound field, such as portions common to both the left and right channels. The omnidirectional pattern may include the lower frequency portions of the audio program 410, such as portions below 400 Hz, which are difficult for listeners to spatially locate.

[0064] If the acoustic environment is not in free space, the playback mode processor 420 may adjust the audio program 410 such that the speaker driver 404 directs the ambient content of the audio program towards the wall and the direct content of the audio program away from the wall.

[0065] The sensing logic component 408 may use the regulatory logic component described above for the Figure 2 system shown.

[0066] In some embodiments, the accelerometer 422 is coupled to the speaker enclosure 400 to detect changes in the position of the speaker enclosure. This may allow for more rapid detection of position changes.

[0067] If a change in the acoustic environment of the speaker enclosure is detected, the sensing logic 408 may fallback to an omnidirectional mode and initiate a calibration procedure. The recalibration is generally transparent to the user. The user may hear some optimization, but nothing is obvious. The playback mode processor 420 may respond to the re-determined acoustic environment after the speaker enclosure has been moved.

[0068] Although certain exemplary embodiments are described and shown in the drawings, it should be understood that such embodiments are merely exemplary and not limiting of the broad invention, and the invention is not limited to the specific constructions and arrangements shown and described, as various other modifications may be made by those of ordinary skill in the art. Not every step or element described is necessary in the particular implementation of the audio system of the present invention. The various steps or elements described in connection with one embodiment may be used as additional or alternative to the steps or elements described in connection with another embodiment. Accordingly, the description is to be regarded as illustrative rather than restrictive.

Claims

1. A method for outputting an audio program through an audio device, the method comprising: a) receiving, by a sensing logic of the audio device, a plurality of microphone signals from at least two microphones of a plurality of microphones, the plurality of microphone signals capturing sounds of an acoustic environment in which the audio device is located; b) determining, by the sensing logic of the audio device, whether there is an acoustic obstacle in the acoustic environment in which the audio device is located based on the plurality of microphone signals; and c) in response to determining that there is an acoustic obstacle in the acoustic environment, providing, by a playback mode processor of the audio device, a first directional beam pattern of ambient content with an audio program to at least two audio amplifiers to output the first directional beam pattern towards the acoustic obstacle through at least two of a plurality of speaker drivers and providing a second directional beam pattern of direct content with the audio program to the at least two audio amplifiers to output the second directional beam pattern away from the acoustic obstacle through the at least two speaker drivers, wherein one audio amplifier corresponds to one speaker driver.

2. The method according to claim 1, further comprising: in response to determining that there is no acoustic obstacle in the acoustic environment, providing, by the playback mode processor, a third directional beam pattern of a high-frequency portion of the audio program and an omnidirectional pattern of a low-frequency portion of the audio program to the at least two audio amplifiers to output the third directional beam pattern superimposed on the omnidirectional pattern through the at least two speaker drivers.

3. The method according to claim 1, wherein determining whether there is an acoustic obstacle in the acoustic environment is automatically performed when the audio device is initially powered on.

4. The method according to claim 1, further comprising determining whether a position change of the audio device has occurred, and in response to determining that a change has occurred, performing a) and b).

5. The method according to claim 1, wherein determining whether there is an acoustic obstacle in the acoustic environment in which the audio device is located based on the plurality of microphone signals by the sensing logic of the audio device includes using at least one of the plurality of speaker drivers to generate a low-frequency omnidirectional pattern to determine whether there is an acoustic obstacle in the acoustic environment.

6. The method according to claim 5, wherein providing the first directional beam pattern and the second directional beam pattern includes generating an audio signal for each of the at least two audio amplifiers to output a portion of the audio program through a corresponding speaker driver, and the method further comprises: determining a low-frequency correction filter in response to the acoustic environment to correct for room effects; and filtering at least one of the audio signals according to the low-frequency correction filter to generate a filtered audio signal for a corresponding audio amplifier.

7. The method according to claim 6, further comprising: collecting, in a first time period, a plurality of measurements from each of the plurality of microphone signals, each of the plurality of measurements being for a second time period shorter than the first time period; Compare each of the plurality of measurements with a target level to determine a proportion of the plurality of measurements that meet the target level; And Disable the filtering if the proportion of the plurality of measurements that meet the target level is below a threshold.

8. The method according to claim 1, further comprising: Collect a plurality of measurements from the plurality of microphone signals, wherein determining whether there is an acoustic obstacle in the acoustic environment is based on the plurality of measurements.

9. An audio system, comprising: A speaker cabinet in which a plurality of speaker drivers are integrated; A plurality of microphones; A plurality of audio amplifiers; And Sensing logic configured to a) receive a plurality of microphone signals from at least two of the plurality of microphones, wherein the plurality of microphone signals capture sounds of an acoustic environment in which the speaker cabinet is located, and b) determine whether there is an acoustic obstacle in the acoustic environment in which the speaker cabinet is located based on the plurality of microphone signals; And A playback mode processor configured to, in response to determining that there is an acoustic obstacle in the acoustic environment, provide a first directional beam pattern with ambient content of an audio program to at least two of the plurality of audio amplifiers to output the first directional beam pattern towards the acoustic obstacle through at least two of the plurality of speaker drivers and provide a second directional beam pattern with direct content of the audio program to the at least two audio amplifiers to output the second directional beam pattern away from the acoustic obstacle through the at least two speaker drivers, wherein one audio amplifier corresponds to one speaker driver.

10. The audio system according to claim 9, wherein the playback mode processor, in response to determining that there is no acoustic obstacle in the acoustic environment, provides a third directional beam pattern with a high-frequency portion of an audio program and an omnidirectional pattern with a low-frequency portion of the audio program to the at least two audio amplifiers to output the third directional beam pattern superimposed on the omnidirectional pattern through the at least two speaker drivers.

11. The audio system according to claim 9, wherein the sensing logic determines whether there is an acoustic obstacle in the acoustic environment automatically when the audio system is initially powered on.

12. The audio system according to claim 9, wherein the sensing logic determines whether a position change of the speaker cabinet has occurred, and in response to determining that a change has occurred, performs a) and b).

13. The audio system according to claim 9, wherein determining whether there is an acoustic obstacle in the acoustic environment based on the plurality of microphone signals by the sensing logic includes using at least one of the plurality of speaker drivers to generate a low-frequency omnidirectional pattern to determine whether there is an acoustic obstacle in the acoustic environment.

14. The audio system according to claim 13, wherein providing the first and second directional beam patterns by the playback mode processor includes generating an audio signal for each of at least two audio amplifiers to output a portion of an audio program through corresponding speaker drivers, and wherein the audio system further comprises: A low-frequency correction filter that filters at least one of the audio signals in response to the acoustic environment to generate a filtered audio signal for a corresponding audio amplifier.

15. The audio system according to claim 14, wherein the sensing logic: Collect a plurality of measurements from each of the plurality of microphone signals during a first time period, each of the plurality of measurements being for a second time period shorter than the first time period; Compare each of the plurality of measurements with a target level to determine a proportion of the plurality of measurements that meet the target level; And Disable the application of the low-frequency correction filter if the proportion of the plurality of measurements that meet the target level is below a threshold.

16. The audio system according to claim 9, wherein the sensing logic further collects a plurality of measurements from the plurality of microphone signals to determine whether there is an acoustic obstacle in the acoustic environment.

17. A non-transitory machine-readable medium storing instructions that, when executed by an audio device, cause the audio device to: a) Receive a plurality of microphone signals from at least two microphones of a plurality of microphones by sensing logic of the audio device, the plurality of microphone signals capturing sounds of an acoustic environment in which the audio device is located; b) Determine, by the sensing logic of the audio device, whether there is an acoustic obstacle in the acoustic environment in which the audio device is located based on the plurality of microphone signals; And c) In response to determining that there is an acoustic obstacle in the acoustic environment, provide, by a playback mode processor of the audio device, a first directional beam pattern of ambient content having an audio program to at least two audio amplifiers to output the first directional beam pattern towards the acoustic obstacle through at least two of a plurality of speaker drivers and provide a second directional beam pattern of direct content having an audio program to the at least two audio amplifiers to output the second directional beam pattern away from the acoustic obstacle through the at least two speaker drivers, wherein one audio amplifier corresponds to one speaker driver.

18. The non-transitory machine-readable medium according to claim 17, wherein the machine-readable medium has additional instructions to, in response to determining that there is no acoustic obstacle in the acoustic environment, provide, by the playback mode processor, a third directional beam pattern of a high-frequency portion of an audio program and an omnidirectional pattern of a low-frequency portion of the audio program to the at least two audio amplifiers to output the third directional beam pattern superimposed on the omnidirectional pattern through the at least two speaker drivers.

19. The non-transitory machine-readable medium according to claim 17, wherein the instructions for determining whether there is an acoustic obstacle in the acoustic environment are automatically executed when the audio device is initially powered on.

20. The non-transitory machine-readable medium according to claim 17, wherein the machine-readable medium has additional instructions to determine whether a position change of the audio device has occurred and, in response to determining that a change has occurred, execute a) and b).

21. The non-transitory machine-readable medium according to claim 17, wherein determining whether there is an acoustic obstacle in the acoustic environment in which the audio device is located by the sensing logic of the audio device based on the plurality of microphone signals includes using at least one of the plurality of speaker drivers to generate a low-frequency omnidirectional pattern to determine whether there is an acoustic obstacle in the acoustic environment.

22. The non-transitory machine-readable medium according to claim 21, wherein the instructions for providing the first directional beam pattern and the second directional beam pattern include generating an audio signal for each of at least two audio amplifiers to output a portion of an audio program through the corresponding speaker driver, and the machine-readable medium has additional instructions to: respond to the acoustic environment to determine a low-frequency correction filter to correct the room effect; and filter at least one of the audio signals according to the low-frequency correction filter to generate a filtered audio signal for a corresponding audio amplifier.

23. The non-transitory machine-readable medium according to claim 22, wherein the machine-readable medium has additional instructions to: collect a plurality of measurements from each of the plurality of microphone signals during a first time period, each of the plurality of measurements being for a second time period shorter than the first time period; compare each of the plurality of measurements with a target level to determine a proportion of the plurality of measurements that meet the target level; and disable the filtering when the proportion of the plurality of measurements that meet the target level is below a threshold.

24. The non-transitory machine-readable medium according to claim 17, wherein the machine-readable medium has additional instructions to collect a plurality of measurements from the plurality of microphone signals, and the instructions for determining whether there is an acoustic obstacle in the acoustic environment are based on the plurality of measurements.

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