Method and apparatus for simultaneously controlling near sound field and far sound field

• US 20120014525A1
• Filed: 04/27/2011
• Published: 01/19/2012
• Est. Priority Date: 07/13/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ko, Sang Chul, Kim, Young Tae, Choi, Jung Woo
• Granted Patent: US 9,219,974 B2
• Time in Patent Office: Days
• US Class Current: 381/17
• CPC Class Codes: H04H 20/83 not sharing the network with any other service
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 2217/03 Parametric transducers where sound is generated or captured by the acoustic demodulation of amplitude modulated ultrasonic waves
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S
• CPC Class Codes: H04S 1/002 Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution control circuits for electronic adaptation of the sound field H04S7/30
• CPC Class Codes: H04S 2420/01 Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD]
• CPC Class Codes: H04S 3/00 Systems employing more than two channels, e.g. quadraphonic H04S5/00, H04S7/00 take precedence
• CPC Class Codes: H04S 5/00 Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation
• CPC Class Codes: H04S 5/02 of the pseudo four-channel type, e.g. in which rear channel signals are derived from two-channel stereo signals
• CPC Class Codes: H04S 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence
• CPC Class Codes: H04S 7/40 Visual indication of stereophonic sound image

Abstract

An apparatus and method for forming a Personal Sound Zone (PSZ) at a location of a listener are provided. An apparatus for simultaneously controlling a near sound field and a far sound field may classify the near sound field and the far sound field based on a distance between an array speaker and a listener, and may control the near sound field and the far sound field and thus, it is possible to perform focusing even when the listener is located in adjacent to the array speaker. Additionally, the apparatus may generate a directive sound source using the array speaker, and at the same time, may reduce a sound pressure in a far field, thereby reducing a sound source spreading to the far field while focusing is performed at the location of the listener.

Claims

1. An apparatus for simultaneously controlling a near sound field and a far sound field, the apparatus comprising:

a filter generating unit to generate a filter to simultaneously control the near sound field and the far sound field based on a ratio of a sound pressure energy at a location of a listener to a sound pressure energy obtained by summing sound pressure energies of a first dark zone and a second dark zone;

a filter processing unit to generate a multi-channel signal by processing a filter value of the generated filter and an input signal; and

an output unit to output the multi-channel signal.

2. The apparatus of claim 1, wherein the filter generating unit comprises:

a near-field setting unit to set a near-field region based on the location of the listener; and

a region classifying unit to classify the near-field region into the location of the listener and the first dark zone of the location around the listener, and to classify a far-field region spaced by a predetermined distance from the location of the listener as the second dark zone.

3. The apparatus of claim 1, wherein the filter generating unit comprises:

a beam width determination unit to determine a beam width of the multi-channel signal by applying a weight based on the sound pressure at the location of the listener;

a beam pattern determination unit to determine a beam pattern of the near sound field by applying a weight based on a sound pressure attenuation in the near sound field in the first dark zone;

a radiation pattern determination unit to determine a radiation pattern of the far sound field by applying a weight based on a sound pressure attenuation in the far sound field in the second dark zone; and

a control weight applying unit to apply a control weight to a factor controlling the beam pattern of the near sound field and a factor controlling the radiation pattern of the far sound field, the control weight being used to simultaneously control the near sound field and the far sound field.

4. The apparatus of claim 3, wherein the control weight applying unit applies the control weight so that a first control weight applied to the factor controlling the beam pattern of the near sound field is inversely proportional to a second control weight applied to the factor controlling the radiation pattern of the far sound field.

5. The apparatus of claim 1, wherein the filter processing unit comprises:

a convolution processing unit to perform a convolution processing on the filter value and the input signal in real-time, and to generate the multi-channel signal based on the convolution processing.

6. The apparatus of claim 1, wherein the filter processing unit comprises:

a gain/delay processing unit to process the input signal using a gain value and a delay value, set in advance.

7. The apparatus of claim 1, wherein the filter generating unit generates a filter for simultaneously controlling the near sound field and the far sound field, based on information of a transfer function from each of a plurality of array speakers to the location of the listener and information of a transfer function from each of the array speakers to a location of the far field.

8. The apparatus of claim 7, wherein the information of the transfer function comprises information of a transfer function based on a theoretically modeled sound source.

9. The apparatus of claim 7, wherein the information of the transfer function comprises information of a transfer function directly measured using a microphone at the location of the listener and another microphone at the location of the far field.

10. The apparatus of claim 1, wherein the filter generating unit comprises:

an array aperture size determination unit to determine an array aperture size based on a frequency of the input signal and a fixed Rayleigh distance; and

a use range setting unit to set a use range of an array based on the determined array aperture size.

11. The apparatus of claim 10, wherein the use range setting unit comprises:

a group setting unit to set array speakers in array groups having different sizes; and

a signal assigning unit to assign the input signal to the set array groups based on a corresponding frequency band.

12. The apparatus of claim 10, wherein the use range setting unit processes, in a channel signal, a window filter calculated based on the determined array aperture size, and sets the use range of the array.

13. The apparatus of claim 1, wherein the filter generating unit comprises:

a focal point change unit to change a focal point in a front or rear of the listener based on a frequency of the input signal, so that a beam width is maintained at a location of ears of the listener.

14. The apparatus of claim 1, wherein the output unit comprises:

an array speaker unit to output the multi-channel signal via an array speaker.

15. The apparatus of claim 1, wherein in the filter generating unit, the filter is generated to control a sound pressure attenuation based on a distance in the second dark zone.

16. A method for simultaneously controlling a near sound field and a far sound field, the method comprising:

generating a filter to simultaneously control the near sound field and the far sound field based on a ratio of a sound pressure energy at a location of the listener to a sound pressure energy obtained by summing sound pressure energies of a first dark zone and a second dark zone;

generating, by way of a processor, a multi-channel signal by processing a filter value of the generated filter and an input signal; and

outputting the multi-channel signal.

17. The method of claim 16, wherein the generating of the filter comprises:

setting a near-field region based on the location of the listener; and

classifying the near-field region into the location of the listener and the first dark zone of the location around the listener, and classifying a far-field region spaced by a predetermined distance from the location of the listener as the second dark zone.

18. The method of claim 16, wherein the generating of the filter comprises:

determining a beam width of the multi-channel signal by applying a weight based on the sound pressure at the location of the listener;

determining a beam pattern of the near sound field by applying a weight based on an attenuation of a near-field sound pressure in the first dark zone;

determining a radiation pattern of the far sound field by applying a weight based on an attenuation of a far-field sound pressure in the second dark zone; and

applying a control weight to a factor controlling the beam pattern of the near sound field and a factor controlling the radiation pattern of the far sound field, the control weight being used to simultaneously control the near sound field and the far sound field.

19. The method of claim 16, wherein the generating of the filter comprises:

determining an array aperture size based on a frequency of the input signal and a constant Rayleigh distance; and

setting a use range of an array based on the determined array aperture size.

20. The method of claim 16, wherein the generating of the filter comprises:

changing a focal point at a rear or a front of the listener based on the frequency of the input signal, so that a beam width is maintained at the location of the listener.

21. The method of claim 16, wherein the filter is generated to control a sound pressure attenuation based on a distance in the second dark zone.