System and method for directionally radiating sound
First Claim
1. A method of providing and operating an audio system that provides audio radiation to a plurality of listening positions located in an environment, the method comprising the steps of:
- (a) providing at least one source of audio signals;
(b) providing, at each of a plurality of the listening positions in the environment, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of each array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array;
(c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element;
(d) defining a cost function that compares acoustic energy in the environment radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy in the environment radiated from the first array to the first listening position;
(e) calculating the cost function; and
(f) iteratively modifying the filter in response to the calculated cost function toward a predetermined criteria so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position.
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Abstract
A method of operating an audio system that provides audio radiation to a plurality of listening positions includes providing at least one source of audio signals. At each listening position, at least one array of speaker elements is provided. A filter is provided between the at least one source and at least one of the speaker elements at a first listening position. The filter is optimized so that the filter reduces acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions, compared to acoustic energy radiated from the first array to the first listening position.
107 Citations
48 Claims
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1. A method of providing and operating an audio system that provides audio radiation to a plurality of listening positions located in an environment, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions in the environment, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of each array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) defining a cost function that compares acoustic energy in the environment radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy in the environment radiated from the first array to the first listening position; (e) calculating the cost function; and (f) iteratively modifying the filter in response to the calculated cost function toward a predetermined criteria so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; and (d) optimizing the filter, based on a comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position, wherein step (d) comprises the steps of (d1) driving each of the speaker elements in the first array to radiate first said output acoustic energy, (d2) detecting the first output acoustic energy at the first listening position and at the at least one other listening position, (d3) determining a first transfer function between the first output acoustic energy detected at the first listening position and the audio signals from the at least one source, (d4) determining a second transfer function between the first output acoustic energy detected at the at least one other listening position and the audio signals from the at least one source, (d5) computing a cost function that compares the first transfer function and the second transfer function, (d6) determining a gradient of the cost function that defines a direction toward reduction of the cost function, (d7) modifying respective portions of the first transfer function and the second transfer function that correspond to the filter according to the direction, and (d8) repeating steps (d5) to (d7) until the result of step (d5) meets a predetermined criteria.
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10. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) optimizing the filter, based on comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position; (e) providing a said first array at each listening position of the plurality of listening positions; (f) detecting whether an occupant is present at a second listening position other than the first listening position; and (g) for the first array at the first listening position, selecting a first set of coefficients for the filter to process audio signals to the first array when no occupant is detected in the second listening position, wherein the second listening position is not a said at least one other listening position at step (d), and if an occupant is detected in the second listening position, selecting a second set of coefficients for the filter, wherein the second listening position is a said at least one other listening position at step (d).
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11. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) optimizing the filter, based on comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position; (e) providing a said first array at each listening position of the plurality of listening positions; (f) detecting whether the at least one array at a second listening position other than the first listening position receives audio signals from the at least one source that are same as or different from audio signals from the at least one source received by the first array at the first listening position; and (g) for the first array at the first listening position, selecting a first set of coefficients for the filter to process audio signals to the first array when the audio signals received from the audio source by the first array are the same as the audio signals received by the at least one array at the at second listening position, wherein the second listening position is not a said at least one other listening position in step (d), and if the audio signals received from the audio source by the first array are different from the audio signals received by the at least one array at the second listening position, selecting a second set of coefficients for the filter, wherein the second listening position is a said at least one other listening position in step (d).
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12. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) optimizing the filter, based on comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position; (e) providing a said first array at each listening position of the plurality of listening positions; (f) detecting whether an occupant is present at a second listening position other than the first listening position; (g) detecting whether the at least one array at the second listening position receives audio signals from the at least one source that are same as or different from audio signals from the at least one source received by the first array at the first listening position; (h) for the first array at the first listening position, selecting a first set of coefficients for the filter to process audio signals to the first array when no occupant is detected in the second listening position or when the audio signals received from the audio source by the first array are the same as the audio signals received by the at least one array at the second listening position wherein the second listening position is not a said at least one other listening position in step (d), and if an occupant is detected in the second listening position, and if the audio signals received from the audio source by the first array are different from the audio signals received by the at least one array at the second listening position, selecting a second set of coefficients for the filter, wherein the second listening position is a said at least one listening position in step (d).
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13. An audio system for a vehicle having seat positions, said audio system comprising:
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at least one source of audio signals; a respective directional loudspeaker array mounted at each of a plurality of the seat positions and coupled to the at least one source so that the audio signals drive the respective directional loudspeaker array to radiate acoustic energy; circuitry that detects whether a first said directional loudspeaker array at a first seat position receives audio signals from the at least one source that are same as or different from audio signals from the at least one source received by a said directional loudspeaker array at least one seat position of the plurality of seat positions other than the first seat position; a filter between the at least one source and the first array that processes the audio signals from the at least one source to the first array so that the first array directionally radiates acoustic energy having a first magnitude to the first seat position and directionally radiates acoustic energy having a second magnitude to the at least one other seat position; and wherein the filter implements a first set of coefficients to process audio signals to the first array when the circuitry detects that the audio signals received from the audio source by the first array are the same as the audio signals received by the at least one array at the at least one other seat position; and the filter implements a second set of coefficients to process the audio signals to the first array if the circuitry detects that the audio signals received from the audio source by the first array are different from the audio signals received by the at least one array at the at least one other seat position, wherein the first set of coefficients and the second set of coefficients are predetermined so that the second magnitude is lower as compared to the first magnitude when the filter implements the second set of coefficients than when the filter implements the first set of coefficients. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) optimizing the filter, based on comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position; (e) providing a said first array at each listening position of the plurality of listening positions; (f) detecting whether an occupant is present at a second listening position other than the first listening position; and (g) for the first array at the first listening position, selecting a first set of coefficients for the filter to process audio signals to the first array when no occupant is detected in the at least one other listening position, wherein the second listening position is not a said at least one listening position at step (d), and if an occupant is detected in the at least one other listening position, selecting a second set of coefficients for the filter, wherein the second listening position is a said at least one other listening position in step (d).
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20. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) optimizing the filter, based on comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position; (e) providing a said first array at each listening position of the plurality of listening positions; (f) detecting whether the at least one array at a second listening position other than the first listening position receives audio signals from the at least one source that are same as or different from audio signals from the at least one source received by the first array at the first listening position; and (g) comprising, for the first array at the first listening position, selecting a first set of coefficients for the filter to process audio signals to the first array when the audio signals received from the audio source by the first array are the same as the audio signals received by the at least one array at the second listening position wherein the second listening position is not a said at least one other listening position in step (d), and if the audio signals received from the audio source by the first array are different from the audio signals received by the at least one array at the second listening position, selecting a second set of coefficients for the filter, wherein the second listening position is a said at least one other listening position in step (d).
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21. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) optimizing the filter, based on comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position; (e) providing a said first array at each listening position of the plurality of listening positions; (f) detecting whether an occupant is present at a second listening position other than the first listening position; (g) detecting whether the at least one array at the second listening position receives audio signals from the at least one source that are same as or different from audio signals from the at least one source received by the first array at the first listening position; and (h) for the first array at the first listening position, selecting a first set of coefficients for the filter to process audio signals to the first array when no occupant is detected in the second listening position or when the audio signals received from the audio source by the first array are the same as the audio signals received by the at least one array at the second listening position, wherein the second listening position is not a said at least one other listening position in step (d), and if an occupant is detected in the second listening position, and if the audio signals received from the audio source by the first array are different from the audio signals received by the at least one array at the second listening position, selecting a second set of coefficients for the filter, wherein the second listening position is a said at least one other listening position in step (d).
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22. A method of providing and operating an audio system that provides audio radiation to a plurality of listening positions located in the environment, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions in the environment, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of each array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; and (d) selecting a set of coefficients for the filter to process audio signals to the at least one speaker element by defining a cost function that compares acoustic energy in the environment radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy in the environment radiated from the first array to the first listening position, calculating the cost function, and iteratively modifying the filter in response to the calculated cost function toward a predetermined criteria so that a relationship between magnitude of the output acoustic energy radiated by the first array to the at least one other listening position and magnitude of the output acoustic energy radiated by the first array to the first listening position meets a predetermined criteria for acoustic isolation. - View Dependent Claims (23, 24, 25, 26, 27)
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28. An audio system for a vehicle having seat positions, said audio system comprising:
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at least one source of audio signals; a respective directional loudspeaker array mounted at each of a plurality of the seat positions and coupled to the at least one source so that the audio signals drive the respective directional loudspeaker array to radiate acoustic energy; a sensor in communication with each seat position of the plurality of seat positions so that the sensor detects whether an occupant is present at a first seat position of the plurality of seat positions and at least one of the seat positions other than the first seat position; a filter between the at least one source and a first said directional loudspeaker array at the first seat position that processes the audio signals from the at least one source to the first array so that the first array directionally radiates acoustic energy having a first magnitude to the first seat position and directionally radiates acoustic energy having a second magnitude to the at least one other seat position; wherein the filter implements a first set of coefficients to process the audio signals to the first array when the sensor detects no occupant in the at least one other seat position; and the filter implements a second set of coefficients to process the audio signals to the first array if the sensor detects an occupant in the at least one other seat position, wherein the first set of coefficients and the second set of coefficients are predetermined so that acoustic isolation between the at least one other seat position and the first seat position is greater when the filter implements the second set of coefficients than when the filter implements the first set of coefficients. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A method of providing and operating an audio system that provides audio radiation to listening positions, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) optimizing the filter, based on comparison of acoustic energy radiated from the first array to at least one other listening position of the plurality of listening positions to acoustic energy radiated from the first array to the first listening position, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position; wherein step (d) comprises minimizing the cost function, and wherein the cost function is an error function that varies directly with the acoustic energy radiated from the first array to the at least one other listening position and varies inversely with the acoustic energy radiated from the first array to the first listening position. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46)
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47. A method of providing and operating an audio system that provides audio radiation to listening positions located in a vehicle cabin, the method comprising the steps of:
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(a) providing at least one source of audio signals; (b) providing, at each of a plurality of the listening positions in the vehicle cabin, at least one array of speaker elements that receives the audio signals and responsively radiates output acoustic energy, wherein the speaker elements of the at least one array are disposed with respect to each other so that the output acoustic energy radiated from respective said speaker elements destructively interfere to thereby define a directional audio radiation from the at least one array; (c) providing a filter between the at least one source and at least one of the speaker elements in a first said array at a first listening position of the plurality of listening positions, wherein the filter processes the audio signals from the at least one source to the at least one speaker element; (d) measuring acoustic energy in the vehicle cabin radiated from the first array to at least one other listening position of the plurality of listening positions, and measuring acoustic energy in the vehicle cabin radiated from the first array to the first listening position; (e) defining a cost function that compares the energy radiated from the first array to the at least one other listening position to the acoustic energy radiated from the first array to the first listening position; and (f) iteratively modifying the filter in response to the cost function, and redefining the cost function in response to the modified filter, until the cost function reaches a predetermined criteria so that the filter reduces a magnitude of acoustic energy radiated from the first array to the at least one other listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position. - View Dependent Claims (48)
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Specification