Immersive seat-centered sound field of vehicle interior

Abstract

An acoustic system and a corresponding method for generating a virtual sound field in an interior of a vehicle are described. A loudspeaker array having at least one first and one second central loudspeaker is used, which is arranged centrally between two vehicle seats. Additionally, the pair of seat speakers is located near the head area of the passenger. The signal processing unit receives an input signal and controls the loudspeaker. In this case, the center speaker is actuated by means of inverted and time-shifted signals in order to generate a zero point in the radiation characteristic. The zero points are directed towards the ear regions of the head region and thus centring the perception of the virtual sound field. Seat speakers create a spatial sound surround around the head region. Optimized sound playback and immersive sound impressions centered on the seat position are achieved by the combination of a central speaker array with targeted manipulation and side seat speakers.

Description

Technical Field

[0001] The present disclosure relates to the technical field of an audio system, in particular to an audio system and a method for generating a virtual sound field in an interior space of a vehicle. Background Art

[0002] In modern vehicles, there is a growing interest in providing passengers with an immersive sound experience. Conventional sound systems in vehicles use multiple speakers placed throughout the vehicle interior space in order to provide the best possible sound. However, these systems may have limitations in terms of precise positioning of sounds and creation of a coherent sound field around the listener, as the sound field perceived by the listener may generally be assigned to the location of the speakers. Therefore, conventional systems may have difficulty ensuring an immersive surround of a seat-centered sound field for passengers at individual seat positions in the vehicle.

[0003] Therefore, there is a need for an improved system and method for generating a virtual sound field for a vehicle interior space that can achieve a more accurate and immersive sound experience. Summary of the invention

[0004] This object is achieved by the subject matter of the independent claim. Further advantageous features are the subject matter of the dependent claims.

[0005] The following describes the solutions disclosed with respect to the claimed sound system and the claimed method for generating a virtual sound field, as well as with respect to corresponding computing devices, computer programs and computer-readable data carriers. Features, advantages or alternative embodiments may belong to different categories, respectively, and vice versa. In other words, these methods may be improved by the features described and / or claimed within the scope of the sound system, and conversely, the sound system may include any steps or features described within the scope of these methods.

[0006] The sound system is configured to generate a virtual sound field in particular in a vehicle interior. The sound system comprises a speaker array, which comprises at least a first and a second center speaker. The speaker array is arranged between a first vehicle seat and a second vehicle seat with respect to a lateral positioning in the vehicle interior. The speaker array can be positioned centrally in the listening environment with respect to a lateral direction.

[0007] In some examples, a center point or a center plane of the loudspeaker array may be centered with respect to the listening environment and / or with respect to two vehicle seats, and a listening position, in particular a head position or a head region of a listener or passenger may be defined. The head region may relate to an ideal or typical spatial region in which there is a head of a person who is located on a vehicle seat, in particular sitting in the middle of the seat and looking forward and thereby adopting an ideal or typical listening posture, i.e. looking directly forward.

[0008] In some examples, the speaker array can be located laterally between two head areas, which can be assigned to a vehicle seat, a listening position, in particular a head position of a listener or a passenger. For example, a central speaker array can be positioned in front of a seat in the longitudinal direction and can be positioned in the transverse direction between two vehicle seats in the vehicle interior. Thus, the speaker array, in particular the center of the speaker array, can be offset in the transverse direction from the position of the head area of ​​the vehicle seat, i.e. laterally offset with respect to the center of the speaker array. The vehicle seat can be positioned laterally offset from the center of the listening environment. The speaker array can be arranged in the middle of the listening environment, for example in front of the driver's seat and / or the front passenger seat, for example in the dashboard.

[0009] In some examples, the loudspeaker array may be arranged between two head areas associated with two vehicle seats, in particular centrally between them, with respect to the transverse direction. The head areas are associated with different vehicle seats, in particular a first head area is associated with a first vehicle seat and a second head area is associated with a second vehicle seat, wherein the vehicle seats may be arranged to the left and to the right of the central loudspeaker array. In other words, the head areas of the vehicle seats may correspond to listening positions, in which the head of the passenger or listener is usually positioned when the passenger or listener sits in the vehicle seat. The head of the listener may have a central ear pointing towards the center and an ear facing away from the center.

[0010] Transverse (in other words, sideways, lateral or transverse) can refer to a direction which extends perpendicularly to the longitudinal axis of the vehicle, in other words the longitudinal axis, and thus perpendicularly to the center axis of the sound system in the longitudinal direction, in other words transversely to the typical direction of travel and / or the orientation of the vehicle seats. Forward or forward direction can refer to the typical direction of travel or the orientation or viewing direction of the vehicle seats. The instrument panel of the vehicle can be arranged at the front of the vehicle in the typical viewing direction of the passengers.

[0011] Longitudinal direction may refer to a direction which extends along the length of the vehicle from the front to the rear, i.e., along the longitudinal axis of the vehicle, i.e., for example, along a typical driving direction and / or along an orientation of a vehicle seat or a typical viewing direction of an occupant. For example, a direction may also refer to a typical seating position of an occupant of a vehicle seat, wherein transverse direction may describe a lateral direction or orientation transverse to a typical orientation / posture of a seat or an occupant or a listener. Likewise, longitudinal direction may describe a direction or orientation in the longitudinal direction of the seat or along a typical orientation / posture of an occupant or a listener.

[0012] Furthermore, the sound system comprises a pair of seat speakers in each of the two vehicle seats, wherein a corresponding pair of speakers is arranged in each of the two vehicle seats so that an ideal or typical head area of ​​a person sitting in the corresponding vehicle seat is arranged between the corresponding pair of seat speakers.

[0013] In some examples, the sound system includes at least a first and a second seat speaker, or generally a near-field speaker, which is placed at or near the first head area and sends the sound signal in the near field directly to the first head area. In other words, a (near-field) speaker or a separate head area speaker is positioned near each head area, which speakers are individually controlled for the corresponding seat area or head area. The first head area is therefore associated with the first vehicle seat and is arranged in a position laterally offset relative to the central speaker array, wherein the central speaker array has corresponding at least a first and a second seat speaker assigned to the head area. The second vehicle seat can be correspondingly configured with a third and a fourth seat speaker. Further vehicle seats that may be adjacent to the center of the listening environment can be correspondingly configured.

[0014] In addition, the audio system also includes a signal processing unit connected to the speaker array and the seat speakers. The signal processing unit includes at least one processor and memory for processing audio signals and generating audio signals, and sends the generated audio signals to the speakers so as to manipulate the speakers to generate sound signals. The signal processing unit is configured so that it receives an input audio signal. The signal processing unit generates a first center audio signal and a second center audio signal based on or using the input audio signal. The signal processing unit manipulates the first speaker using the first center audio signal based on processing the input audio signal, and manipulates the second center speaker using the second center audio signal. The second center audio signal is inverted with respect to the first center audio signal and is shifted forward or delayed in time by a predetermined time period, as described in more detail with reference to the accompanying drawings. By delaying the manipulation of the second center speaker using the inverted audio signal, the zero point in the radiation characteristic of the speaker array or in other words the minimum value in the sound pressure generated by the speaker array moves in the direction of the head area of ​​the first vehicle seat.

[0015] The first head area may have a central side or central side area, which is directed or oriented toward the center of the listening environment and / or directed toward the direction of the second vehicle seat. The zero point may be oriented or positioned toward the central side area of ​​the head area. The zero point may at least partially intersect or overlap with the central side area. Typically, one ear of the listener may be located in this area, so that the listener perceives a smaller sound pressure with this ear than with another ear directed outward. Therefore, the central side area may also be referred to as an ear area or an inner ear area. Therefore, the ear area may be a partial area of ​​the ideal head area, in which the (middle, i.e., centrally directed) ear of the passenger / listener in an ideal or typical sitting position is located. The first zero point may extend between the first vehicle seat and the second vehicle seat, or be located between the vehicle seats. The second zero point may extend between the first vehicle seat and the second vehicle seat, or be located between the first vehicle seat and the second vehicle seat. Both the first and second zero points may extend between the first vehicle seat and the second vehicle seat or be located between them. The corresponding zero point axis describing the first and / or second zero points may extend between the vehicle seats from the center of the speaker array. A speaker axis connecting the centers of the center speakers may extend between the first vehicle seat and the second seat.

[0016] In other words, in the described sound system with a center loudspeaker array, the dipole pattern generated by the superposition of the first and second center loudspeakers with the aid of inversion has a zero point. The zero point is a point or area at which the sound pressure is reduced to a minimum by interference. The zero point can also be referred to as an area or axis with a sound pressure minimum or sound pressure suppression. At the zero point, the sound pressure is greatly reduced or equal to zero, and near the zero point, the sound pressure is also reduced in any case. By targeted manipulation of the loudspeaker array, the position of the zero point can be influenced and thus the directional characteristics. The movement of the zero point results in a displacement of the area with minimized sound pressure. The zero point is used to influence the perception of the center point of the virtual sound source.

[0017] The first zero point in the radiation characteristic of the sound signal of the loudspeaker array is not centered but rather displaced laterally to the ideal head area of ​​the first vehicle seat. The zero point is therefore at least partially located in an area in which the middle ear of the passenger, i.e., pointing toward the center of the sound system, is located. This area can be referred to as a side area facing the center, which can be positioned adjacent to the head area or at least partially intersects with the head area on a hemisphere facing the center of the head area. This ensures that, on the central side of the head area, in particular in the edge area where the listener's ears are located, a lower sound pressure is present due to the playback of the audio input signal due to the zero point, and the positioning of the presented sound events is affected.

[0018] The first zero point reaches the ideal head region in the vicinity of an ear of a person sitting on the first vehicle seat, which ear faces the other vehicle seat in the same viewing direction of both persons on the two vehicle seats.

[0019] The null point generates a reduced sound pressure, wherein the center of the virtual sound field is therefore centered directly in front of the head area as perceived by the listener. Additionally, the signal processing unit controls the first seat speaker with the first seat speaker audio signal based on the processing of the input audio signal, and controls the second seat speaker with the second seat speaker audio signal. The sound signals of the seat speakers overlap with the sound signals of the speaker array, and a spatial sound surround of the virtual sound field around the head area is generated based on the virtual sound field perceived centered in front of the passenger.

[0020] In some examples, the head area, in particular the ear area, can be located at least partially in the near field of the loudspeaker. For example, the near field can refer to a distance in a non-reflecting open space, for example less than 1 / 4 of the wavelength of the lowest frequency to be reproduced, but due to multiple reflections in the vehicle, the distance of the seat loudspeaker should be selected to be smaller.

[0021] The first seat speaker can be positioned in the near field area in the left hemisphere of the first head area associated with the first vehicle seat, while the second seat speaker is positioned in the near field area in the right hemisphere of the first head area. Therefore, the first seat speaker can be located near the left half of the head area, in other words, in the near field area of ​​the left ear of the listener, while the second seat speaker corresponds to the right half, and vice versa. This arrangement can produce a spatial sound surround around the listener's head. Here, the seat speakers are arranged near the head area, in particular on the central side area (ear area). In some examples, the ear area is less than 20 cm or 15 cm or 10 cm or 5 cm away from the seat speaker. Among them, as a reference, for example, the membrane of the speaker (or the center point of the membrane), or the center point of the speaker, or the point of the speaker closest to the head area, and the ear of the listener, or the center point of the ear area, or the point of the ear area closest to the speaker can be selected.

[0022] In a further example, the loudspeaker can be positioned, for example, less than 15 cm, 20 cm, 30 cm or 40 cm from the center of the head area in order to produce a good sound impression in the near field. The first and second seat loudspeakers can be positioned in the rear hemisphere or the front hemisphere of the first head area. The seat loudspeakers can be headrest loudspeakers arranged in the headrest of the first vehicle seat. The corresponding situation applies to the seat loudspeakers of the second vehicle seat. The seat loudspeakers can be arranged centrally with respect to the ideal head area of ​​the respective vehicle seat.

[0023] The first and second center speakers are arranged in a compact spatial configuration. Here, the distance between the speakers can, for example, be less than 100% or <75% or <50% or <25% or <10% or <5% of the diameter of one of the speakers, or, for example, less than 5 mm or <10 mm or <20 mm or <30 mm or <5 cm or <10 cm. In other words, the distance between the centers of the first speaker and the second speaker can be selected so that the distance is less than half the speaker diameter of the first speaker plus half the speaker diameter of the second speaker plus 5 mm or 10 mm or 20 mm or 30 mm or 5 cm or 10 cm. Alternatively, it is possible that the center speakers are arranged directly adjacent to each other. Thereby, the position of the zero point in the radiation characteristic of the center speaker array can be effectively controlled.

[0024] In the sound system, the first and second center speakers may respectively include broadband speakers or mid-high frequency speakers. The first and second speakers may be configured to radiate sound signals using the same frequency range and / or the same radiation characteristics. The first and second center speakers may be the same speaker. For example, it is also possible that each center speaker consists of a speaker pair, i.e. a middle speaker and a tweeter. In this case, the speaker pairs, i.e. the middle speaker and the tweeter must be arranged one after the other in the longitudinal direction. The center speaker may be arranged in the dashboard of the vehicle or in the roof of the vehicle. The sound system may include at least two center speakers, and the two center speakers may be configured as mid-high frequency speakers, for example, as speakers with the same structure. The two main speakers are positioned so that they are, for example, embedded in the dashboard of the vehicle or in the ceiling of the roof, and therefore embedded in the middle in front of the vehicle seat.

[0025] The orientation of the central loudspeaker array can be defined by a connecting line, i.e. an axis, in which the center points of the first and second loudspeakers lie. This axis can also be referred to as the loudspeaker axis. It is possible that the loudspeaker axis is oriented along the longitudinal axis of the vehicle, i.e. parallel to the longitudinal axis (longitudinal axis) of the vehicle. In order to visualize the spatial orientation, one can imagine the position and orientation of the loudspeakers in a three-dimensional projection onto the vehicle floor or onto the X / Y plane. This means that when viewing the vehicle from above (top view), the orientation of the loudspeaker axis relative to the vehicle axle can be seen.

[0026] In some examples, the speaker axis can be positioned at an angle greater than 5° or 10° or 20° or 30° or 45° or 60° relative to the longitudinal axis, for example. By rotating the speaker axis, the audio output can be optimally adapted to the position of the vehicle seat and the lateral and longitudinal position relative to the seat position.

[0027] The signal processing unit generates and uses corresponding specific audio signals for corresponding speakers to control. The first and / or second center audio signals may include audio signals related to the input audio signal.

[0028] For example, correlated audio signals may include signals that are significantly similar or related to the original input audio signal, particularly signals that are related to its waveform or pattern. This means that changes or patterns in one signal generally follow or mirror similar changes or patterns in the other signal. The term "correlated audio signals" in the patent claims excludes decorrelated signals such as those that occur in reverberation effects.

[0029] In some examples, correlation may include that the two signals have similar waveform patterns, meaning that the peaks and valleys of the correlated signal correspond to the peaks and valleys of the input audio signal. Another indication of correlation may be a coherent phase relationship between the two signals, such that the phase structure of the two signals remains constant relative to each other despite possible shifts over time. Furthermore, analysis over a frequency range may confirm that the two signals have similar spectral content, indicating correlation of their frequency patterns. Finally, a correlated signal may have a specific energy or amplitude relationship to the original input audio signal, indicating that it is derived from the original signal by a specific amplification or attenuation process.

[0030] The audio system may be configured such that the seat speaker audio signals correlated with the input audio signal and / or the center audio signal include decorrelated audio signals.

[0031] To achieve improved spatial audio perception in the vehicle, the seat speaker audio signals do not directly reflect the input signal. This may be referred to as decorrelation. The decorrelated audio has little or no identifiable relationship to the original input audio signal. The decorrelated signal typically includes spatial effects such as multiple reflections, diffuse field effects, or reverberation effects, where a complex combination of many reflected sound waves aggregate and produce a signal that is significantly different from the original signal.

[0032] By decorrelating the seat speaker audio signals from the input audio signal, it means that they do not have the same characteristics or patterns of the input signal. This may mean that although both signals come from the same audio source, the waveform of the signal played through the seat speakers changes significantly compared to the input audio signal. The phase relationship between the two signals may be inconsistent or variable, whereby the coherent structure of the initial signal is interrupted. The spectral content of the decorrelated signal may differ from the input audio signal by more than a predetermined limit value over the frequency range. The energy or amplitude relationship may also not be constant or predictable, indicating independent amplification or attenuation processing of the seat speaker signals. The purpose of this decorrelation is to ensure an ambient and spatial sound experience in the vehicle interior space.

[0033] The sound system may be configured such that the seat speaker audio signals include audio signals provided with reverberation based on the input audio signal and / or the center audio signal. The sound system may be designed such that the sound signals emitted by the speakers in the seats are processed using echo or reverberation. The reverberation may be based on the original audio input and / or the audio signal of the center speaker.

[0034] The sound system may include at least one third and fourth seat speakers positioned in a second head area associated with the position of a second vehicle seat. For example, the first head area may be arranged in a left hemisphere of the listening environment, and the second head area may be arranged in a right hemisphere of the listening environment. The center of the compact speaker array is arranged between the first listening area and the second listening area in a lateral direction. The center of the compact speaker array may be positioned between the first head area and the second head area on a longitudinal axis, in particular a middle axis or an axis of symmetry. The signal processing unit of the system may also be configured such that, based on processing of an input audio signal, it controls the third seat speaker by a third seat speaker audio signal, and controls the fourth seat speaker by a fourth seat speaker audio signal, so as to generate a spatial sound surround of a virtual sound field around the second head area.

[0035] In some examples, the first and second seat speaker audio signals can be generated based on or using the position of the first head region in the listening environment. In some examples, the third and fourth seat speaker audio signals can be generated based on or using the position of the second head region in the listening environment. Thus, an interactive and immersive listening environment can be generated for two listeners.

[0036] In these examples, an improved and spatial sound surround can be generated for two passengers of a vehicle by placing an additional counterpart of the seat speakers near the second head area, typically near the front passenger side. By positioning the compact speaker array and the additional seat speakers near the respective listening positions, an immersive sound experience can be generated with a sound field in front of the listener and also around the listener (surroundings) with a surround spatial sound for the two respective passengers of the vehicle, the sound field being respectively perceived in a longitudinal position centered in front of the respective passenger.

[0037] The first and second central loudspeakers, in particular the center of the loudspeaker, can be arranged between the first head area and the second head area on an axis passing through the center. This can help the driver and the front passenger to experience a harmonious and centered sound experience in the vehicle.

[0038] The first zero point of the compact loudspeaker array can be moved in the direction of the head area of ​​the first vehicle seat. The second zero point of the compact loudspeaker array can be moved in the direction of the head area of ​​the second vehicle seat, the second zero point being symmetrical with respect to the first zero point about a longitudinal axis passing through the centers of the first and second center loudspeakers.

[0039] The first and second center loudspeakers, in particular their centers or center points, can be arranged on a longitudinal symmetry axis or symmetry plane of the first and second head regions, in other words can be positioned longitudinally one after the other. In other words, the connecting line between the centers of the loudspeakers or the loudspeaker connection axis can extend in the longitudinal direction.

[0040] Speakers closer to the vehicle seat or listening position / head area may receive a delayed signal.

[0041] However, it is also possible that the connecting line extends at an angle of less than 5°, less than 10°, less than 20°, less than 45°, less than 60°, or less than 90° relative to the longitudinal direction. In a particularly preferred example, the angle may be 90° or 0°.

[0042] The position of the center of the loudspeaker array can differ from the central position with respect to the transverse direction and can be positioned accordingly adapted with respect to the longitudinal direction so that the first zero point and the second zero point extend in the direction of the first head region or the second head region.

[0043] The compact speaker array generates zero points on both sides of the speaker axis or in two half spaces about the speaker axis, which can be referred to as the first zero point and the second zero point. In other words, the speaker array can form zero points on both sides of the connecting axis or connecting plane between the first center speaker and the second center speaker.

[0044] In a particularly preferred example, the central loudspeaker can be arranged in a longitudinal arrangement, i.e. in the longitudinal direction on the longitudinal axis of the vehicle interior, in particular on the middle axis between the head areas. Due to the symmetry of the directional characteristics of the array, two seats or their head areas can be addressed or overlapped at a zero point, respectively.

[0045] The first and / or second loudspeaker may have a symmetrical radiation characteristic. In this case, the zero point or the axis of the zero point may also extend symmetrically with respect to the connection axis or the connection plane.

[0046] The first zero point can be oriented toward the first head region, in particular toward the center side region, where the listener's ears are positioned, and the second zero point can be oriented toward the second head region, in particular toward the center side region, where the ears of the other listener are positioned. Thus, the impression of a virtual sound field centered on the seat can be created for one or both listeners.

[0047] One of the first or second center loudspeakers may be closer in the longitudinal direction to the center of the listening environment or to the vehicle seat or to at least one of the head regions. The center loudspeaker may be operated using the center audio signal delayed by the time period.

[0048] The center audio signal of a loudspeaker closer to the center of the listening environment can have a time delay relative to another center audio signal. A person skilled in the art is aware of different signal processing techniques in order to manipulate the phase and time offset of an audio signal. For this purpose, for example, a delay filter, an all-pass filter, a phase shifter or a time offset block in a digital signal processor are included. They can be used to shift the second center audio signal in time relative to the first center audio signal. Similarly, in audio technology, methods for inverting audio signals are prior art. For this purpose, for example, an inverter or a digital signal processing device can be used. The loudspeakers and seats of the center loudspeaker array are placed with high spatial precision, for example, on defined mounting points. Therefore, the sound field simulation of a given loudspeaker arrangement can predetermine and optimize the resulting directional characteristics or the position of the zero point in a computational manner, for example, by optimization. Therefore, the time offset can be optimized with the help of simulation. The radiation characteristics of the loudspeaker system can be measured by measurement methods, such as near-field scanning. Therefore, the following technology is known to the person skilled in the art, namely all necessary simulation, measurement and optimization technologies, in particular in the adjustment of loudspeaker positioning, signal inversion and time offset between channels, in order to realize the used control of the loudspeaker signals and the positioning of the loudspeakers for the desired directional characteristics and the control of the zero point in the head area.

[0049] A corresponding method is provided for generating a virtual sound field in a vehicle interior.

[0050] The method for generating a virtual sound stage in a vehicle interior is based on an audio system having the following components: a loudspeaker array arranged in the middle of the vehicle interior, having a first and a second center loudspeaker, at least one first and a second seat loudspeaker, which are positioned in the vicinity of a first head area, which is associated with a laterally offset position of a first vehicle seat, and a signal processing unit, which is connected to the loudspeaker array and the seat loudspeakers and receives an input audio signal in order to generate a corresponding audio signal of the loudspeaker.

[0051] The method is performed by a signal processing unit and includes the following steps.

[0052] In one step, an input audio signal is received by a signal processing unit. In another step, based on the processing of the input signal, a first center speaker is controlled with a first center audio signal and a second center speaker is controlled with an inverted and delayed second center audio signal. As a result, the zero point of the radiation characteristic is shifted in the direction of the head area of ​​the first seat and a reduced sound pressure is generated, whereby the center of the virtual field is positioned in the middle in front of the head area. In another step, also based on the processing of the input signal, a first seat speaker is controlled with a first seat speaker audio signal and a second seat speaker is controlled with a second seat speaker audio signal, whereby a spatial sound surround is generated around the head area.

[0053] The method may also include one or more features or steps, or any combination of features or steps, described in conjunction with the sound system disclosed herein.

[0054] The method may be a computer-implemented method, for example executed by at least one computing device.

[0055] A computing device for generating a virtual sound field in the interior space of a vehicle, such as a computing device or a computer or a signal processing unit, includes a computing unit (processor), a storage unit (memory), and an optional interface for receiving and providing audio signals, wherein the storage unit includes commands executable by the computing unit, and when executed by the computing unit, these commands cause the computing unit to perform steps of any method or any combination of methods according to the present disclosure.

[0056] The computer program or computer program product comprises instructions which, when executed by a processor, cause the processor to perform the steps of any method or any combination of methods according to the present disclosure.

[0057] For example, a computer program may include software that can be loaded into a memory of a programmable control device or a computing unit of a medical imaging system. When the computer program product is run in the control device, the described method can be performed using this computer program product. In this case, the computer program product may require program tools, such as libraries and auxiliary functions, in order to implement the described method. In other words, the claims for the computer program product should in particular protect software that can execute the described method. In this case, the software can be source code (such as C++) that still has to be compiled and bound or only interpreted, or it can also be an executable software code, which only has to be loaded into the corresponding computing unit or control device for execution.

[0058] The computer-readable data carrier includes instructions that, when executed by a processor, cause the processor to perform the steps of any method or any combination of methods according to the present disclosure. For example, data and instructions for executing the disclosed methods may be stored in a distributed database, in particular a cloud.

[0059] For example, the data carrier can be a DVD, a magnetic tape, a hard disk or a USB stick on which electronically readable control information, in particular the described software, is stored. When the data carrier reads this control information (software) and stores it in a control device or a computing unit of the magnetic resonance system, the described method can be executed.

[0060] The sound system, the computing device, the computer program or the computer program product and the computer-readable data storage are configured to perform any method or any combination of methods according to the present disclosure.

[0061] For such a device, a computer program, a cloud solution and an electronically readable data carrier, technical effects corresponding to the technical effects of the device according to the present disclosure can be achieved.

[0062] A vehicle includes any audio system according to the present disclosure.

[0063] Although the features described above and in the following detailed description are described in conjunction with specific examples, it should be understood that these features can be used not only in corresponding combinations, but also alone or in any combination, and features from different examples of systems, devices and methods can be combined with each other and are therefore related to each other, unless otherwise explicitly stated.

[0064] Therefore, the above summary should only provide a brief overview of features of some embodiments and implementations and should not be construed as limiting.Other implementations may include other features besides those described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The disclosure is explained in more detail below with reference to preferred exemplary embodiments and with reference to the accompanying drawings.

[0066] Here, the same reference numerals in the drawings denote the same or similar elements. The drawings are schematic diagrams of various embodiments of the claimed solution, wherein the elements shown in the drawings are not necessarily shown to scale. Instead, the various elements shown in the drawings are reproduced so that their functions and common purposes are understandable to a person skilled in the art.

[0067] Figure 1 Dipole radiation characteristics of first and second center speakers without signal delay according to a non-claimed example are shown.

[0068] Figure 2 FIG. 1 shows a circuit diagram with signal delay according to various embodiments. Figure 1 The dipole radiation characteristics of the center speaker.

[0069] Figure 3 The positioning of a seat-centered virtual sound field based on the movement of a symmetrical zero point of a center speaker's dipole radiation characteristic is shown according to various embodiments.

[0070] Figure 4 A virtual sound field that surrounds vehicle occupants is shown according to various embodiments.

[0071] Figure 5 A flow chart with steps for executing a method for generating a virtual sound stage according to various exemplary embodiments is shown.

[0072] Figure 6 A schematic diagram of a sound system according to various embodiments is shown, the sound system being configured to generate a virtual sound field. DETAILED DESCRIPTION

[0073] In the following, the concepts of exemplary embodiments are explained in detail with reference to the accompanying drawings.

[0074] In conjunction with the following description of the embodiments, the above characteristics, features and advantages and the ways and methods of how to achieve them become clearer and easier to understand. It should be noted that the description of the embodiments should not be understood as limiting. The scope of the claimed solution should not be limited by the embodiments described later or the drawings which are used for illustration only.

[0075] These drawings may be considered as schematic diagrams, and the elements shown in the drawings are not necessarily shown in scale. On the contrary, different elements are shown so that their functions and their common purposes are apparent to those skilled in the art. Any connection or coupling between a functional block, device, component, module, or other physical or functional units shown in the drawings or described herein may also be realized by direct or indirect connection or coupling. Coupling between components may also be established by wireless connection. Functional blocks may be realized by hardware, firmware, software, or a combination thereof.

[0076] Different techniques for generating a virtual sound field that surrounds the seat position are described in more detail below. The disclosed techniques are described in connection with the interior space of a vehicle, but it is to be understood that these are not limited thereto and can be used in every arbitrary scenario, exterior space or interior space, in which a compact center speaker array and near-field speakers individualized to the listener are arranged. For example, in interior spaces for video projection, conference rooms, movie theaters, any other vehicles such as airplanes or ships, and other situations where the speaker array is not arranged in the middle in front of one or more listeners and there are mechanical structures, such as seats, near the listeners.

[0077] Figure 1 The dipole radiation characteristic of a speaker array without signal delay according to a non-claimed example is shown, the speaker array comprising a first center speaker 1 and a second center speaker 2 .

[0078] exist Figure 1 In the example of , the center loudspeakers are arranged symmetrically with respect to the center axis. One loudspeaker is located in the left hemisphere of the radiation characteristic and the other loudspeaker is located in the right hemisphere of the radiation characteristic. Both loudspeakers operate without signal delay but with an inverted second center audio signal, wherein reference numerals 11 and 12 show first and second zero points in the dipole radiation characteristic extending along the center axis.

[0079] The two loudspeakers 1, 2 are operated in a dipole configuration. This means that the loudspeaker signal of one of the loudspeakers is inverted with respect to the signal of the other loudspeaker, but not time-shifted. This configuration leads to destructive interference in the middle plane between the loudspeakers, whereby nulls 11, 12 are formed in the radiation characteristic. These nulls can extend along a null axis, at which the perceived sound pressure is strongly reduced or essentially zero. In other words, the nulls can be characterized by an axis or direction and extend along this axis or direction.

[0080] As in Figure 1 As can be seen in FIG. 1 , the null point extends along a center plane between the loudspeakers, ie centrally between them.

[0081] For example, a processor, such as a DSP (digital signal processor), can be used to generate and control the null in the radiation characteristic. This can be achieved in such a way that an inverted signal is fed into one of the loudspeakers and / or by adding a time delay to the signal of one of the loudspeakers in order to steer the null to a specific location or in a specific direction, as will be explained in detail later.

[0082] Figure 2 FIG. 1 shows a signal delay with a predetermined time period Δt according to various embodiments. Figure 1 The dipole radiation characteristics of the center speakers 1 and 2.

[0083] As in Figure 2 As can be seen in Figure 1 Similarly, the dipole radiation characteristics of the first center loudspeaker 1 and the second center loudspeaker 2 are produced in FIG. A dashed center axis 13 can be seen in the middle.

[0084] and Figure 1 Differently, in Figure 2 In the embodiment, the zero points 11 and 12 are not arranged along the central axis, but along an axis rotated by a specific angle relative to the central axis. The rotation of the zero point axis occurs in such a way that the second center audio signal of the second center loudspeaker 2 is inverted and additionally delayed in time by a time period Δt relative to the first center audio signal of the first center loudspeaker 1.

[0085] Due to the time delay of the inverted signal at the second center loudspeaker 2 , the resulting null axis is shifted in the dipole radiation characteristic and correspondingly rotated by this angle relative to the center axis between the two center loudspeakers 1 and 2 .

[0086] The dotted speaker axis 14 can be seen between the center points of the center speakers 1 and 2. Figure 1 Differently, due to the signal delay, the dipole radiation characteristic is no longer symmetrical with respect to the center axis 13. However, the zero points 11 and 12 are arranged symmetrically with respect to the speaker axis 14 between the center points of the center speakers 1 and 2, because the center speakers 1, 2 have radiation characteristics symmetrical with respect to the center axis 13, respectively.

[0087] Figure 3 The positioning of a seat-centered virtual sound field based on the movement of the symmetrical zero points 11 , 12 of the dipole radiation characteristics of the center loudspeakers 1 , 2 according to different embodiments is shown.

[0088] Figure 3 Two center loudspeakers 1 and 2 are shown, which are also Figure 1 and Figure 2 The dotted central axis extends between the center points of the center speakers 1 and 2.

[0089] Furthermore, head areas 21, 22 are shown, which represent the typical or ideal head position of a person positioned on a vehicle seat offset to the left and right of the center loudspeaker array. A delay Δt is shown at zero points 11, 12, which signals that the audio signals of the center loudspeakers are offset in time with respect to one another.

[0090] Furthermore, the zero points 11, 12 of the resulting dipole radiation characteristic are shown, which are respectively located on axes rotated at a specific angle relative to the central axis between the central loudspeakers. The axes or directions of the zero points 11, 12 are symmetrical relative to the loudspeaker axis and can therefore be controlled to another head area associated with another vehicle seat of the first and second vehicle seats, respectively.

[0091] The positioning of the virtual sound field to the left and right of the center speaker shows that by positioning the zero points 11 and 12 based on the signal delay, the virtual sound field is moved laterally from the center by the reduction of the sound pressure at one of the two ears and is perceived as centered by the person in the seat.

[0092] exist Figure 3 In FIG. 1 , the center loudspeakers 1 and 2 are positioned such that their center points are located on the longitudinal axis between two head positions 21 and 22. The head positions 21 and 22 represent the ideal or typical head area of ​​a person who is positioned on a seat of a vehicle and looking forward in the direction of travel.

[0093] The null points 11 and 12 of the resulting dipole radiation characteristic are directed toward the lateral head regions, in particular toward the centrally directed lateral regions of the head regions 21 and 22. This means that the null points at least partially cover the region of the head region where the listener's ears are located.

[0094] By means of the targeted orientation of the zero points 11 and 12 towards the head area on the side where the ears are located, the perception of the sound source center point of the virtual sound field is centered in front of the respective head area for each listener in the seats 21 and 22 .

[0095] The longitudinal positioning of the center loudspeakers 1 , 2 between the head areas in combination with the lateral orientation of the ear areas with a zero point to the head area thus enables an individual seat-centered perception of the virtual sound stage for each listener in the vehicle.

[0096] Overall, Figure 3 It is shown that by shifting the zero point in the dipole radiation characteristic by means of a signal delay, the positioning of the virtual sound field can be adjusted individually for each listener in the seats 21 and 22 .

[0097] Figure 4 A virtual sound field that surrounds vehicle occupants is shown according to various embodiments.

[0098] Figure 4 A sound system 100 for generating a virtual sound stage in a vehicle interior according to various exemplary embodiments is schematically shown.

[0099] like Figure 4 As shown, a speaker array having a first center speaker 1 and a second center speaker 2 is arranged in a central area of ​​a vehicle, such as in a dashboard or a roof panel of the vehicle. The center speakers 1 and 2 are arranged in a compact spatial configuration.

[0100] The center speakers 1 and 2 respectively include mid-high frequency speakers and are configured with the same frequency range and the same radiation characteristics. The center audio signal of the center speaker array is controlled in correlation with the input audio signal.

[0101] The center loudspeakers 1 and 2 are positioned one behind the other in the longitudinal direction so that their center points are located on the axis of symmetry between the two head positions 21 and 22 in the longitudinal direction.

[0102] These head positions 21 and 22 represent the ideal head area of ​​a person who is positioned on the left and right seats in the vehicle, respectively. Here, the person looks forward in the direction of travel. His head area is arranged laterally offset from the central loudspeakers 1 and 2.

[0103] In each seat there is a pair of seat speakers surrounding the head area. The seat speakers can be integrated in the headrest. In the first seat there is a pair of seat speakers with seat speakers 3 and 4. In the second seat there is a second pair of seat speakers with seat speakers 5 and 6.

[0104] The seat loudspeaker pair is arranged centrally relative to the respective head region and spatially surrounds the head region. Its audio signal is decorrelated with the input signal and may have a reverberation effect, for example.

[0105] Two zero points 11 and 12 are shown between the two center loudspeakers 1 and 2, which are located on axes that are symmetrical (with respect to the loudspeaker axis) and are each rotated with respect to a longitudinal axis passing through the center point of the loudspeaker. The zero points are caused by the dipole radiation characteristic of the center loudspeakers, wherein the audio signal of the second center loudspeaker 2 is inverted and delayed in time with respect to the first center loudspeaker 1.

[0106] The null points 11 and 12 are directed toward the lateral head regions 21 and 22, respectively, more precisely toward the lateral regions of the ears of the person pointing toward the center. Therefore, the null points partially cover the ear regions in the head and generate reduced sound pressure there.

[0107] Thus, for each listener, the perception of the center point of the sound source of the virtual sound field is centered in front of their head area. The virtual sound field is shown by the thick arrow positioned in front of the head area.

[0108] All speakers are connected to a signal processing unit (not shown), which receives input audio signals and generates center speaker and seat speaker signals accordingly, as well as individually controls the speakers.

[0109] By means of a sound system having a center speaker array and side seat speakers, a personalized virtual sound space can be generated for each listener in the vehicle, which provides an impressive, surround sound experience.

[0110] Figure 5 A flow chart according to various embodiments is shown, which has steps for executing a method for generating a virtual sound field.

[0111] The method can be performed, for example, by a signal processing unit of a (vehicle) sound system and starts with step S10. An input audio signal is received in step S20. In step S30, based on the processing of the input audio signal, a first center speaker is controlled by a first center audio signal and a second center speaker is controlled by a second center audio signal which is inverted and delayed relative to the first center audio signal. In step S40, based on the processing of the input audio signal, the seat speakers of a seat speaker pair or two seat speaker pairs are controlled by means of corresponding seat speaker audio signals. The seat speaker audio signals contain audio signals which are decorrelated relative to the input audio signal and / or the center audio signal, thereby producing the effect of a surround virtual sound field which is perceived for each vehicle seat with a separate different center.

[0112] Figure 6 A schematic diagram of a sound system 100 is shown according to various embodiments, the sound system being configured to generate a virtual sound field.

[0113] Figure 6 The schematic diagram shows an audio system 100 for generating a virtual sound field in a vehicle interior space, which includes a signal processing unit 7 connected to center speakers 1 , 2 and seat speakers 3 , 4 , 5 , 6 .

[0114] The signal processing unit 7 comprises at least one processor and memory for processing audio signals, and an interface for receiving and providing audio signals, wherein the memory unit comprises commands executable by the computing unit, which, when executed by the computing unit, cause the computing unit to perform the steps of any method or any combination of methods according to the present disclosure. The center speakers 1 and 2 form a center speaker array. The seat speakers 3, 4 and 5, 6 represent seat speaker arrays, which respectively surround the head area of ​​a person on the seat.

[0115] The signal processing unit receives an input signal and controls the speaker based on the signal to generate a separate surrounding virtual sound field for each listener in the vehicle. The virtual sound field centered on the seat can surround the listener with sound (surround effect), and the virtual sound field extends around the listener.

[0116] From the above, we can draw the following conclusions:

[0117] Typically, the radiation characteristics (directional characteristics) caused by time shift can be simplified as a rotating dipole characteristic. However, in detail, due to the movement of the zero point, the radiation characteristics may not have a complete dipole characteristic (rotating dipole), but have different directional characteristics (polarization patterns) and zero points located at different spatial positions. By controlling the spatial position of the zero point, the zero point is maintained, wherein the zero point is located at a new spatial position, but the pattern around the zero point may change. This can be called a controlled dipole.

[0118] The volume levels of the first and second center audio signals may be adapted based on the time offset of the center audio signal in order to produce a more realistic spatial listening effect.

[0119] Furthermore, in minimum phase tuning, the frequency response of the first and / or second loudspeaker signal may be adapted based on the duration in order to further improve the spatial (ie surround) listening effect.

[0120] The audio signal may correspond to a left or right channel of a stereo audio signal. The other stereo channels may be played to the listener simultaneously through the same sound system by the disclosed method.

[0121] The first center audio signal can be inverted so as to produce a second loudspeaker signal, wherein a radiation characteristic of the loudspeaker is produced which corresponds to an eighth dipole having a zero (zero pole) at its center. The radiation pattern of the eighth dipole is strongly directional, i.e. the energy is radiated mainly in two main lobes perpendicular to the zero axis (or zero plane). The main lobes are located in the direction of the two half sides of the eight, and the dipole characteristic has a zero in the direction of the "loop" of the eight.

[0122] A time shift (of a predetermined duration) may be added to the first or second loudspeaker signal.The spatial position of the null point is determined by the duration of the loudspeaker signals relative to each other, based on interference effects of the sound (pressure) waves.

[0123] The zero point is shifted by the signal and steered towards the listener's ear based on the duration. A virtual sound field is generated in such a way that all loudspeakers send sound signals that can be perceived by the listener based on the corresponding audio signal. For example, by steering the zero point to the listener's right ear, the virtual sound field is shifted to the left for one listener, and vice versa.

[0124] It is also clear to a person skilled in the art that the disclosed technology can be applied to a plurality of application cases in which a compact center speaker arrangement in combination with individual near-field speakers centered on the seats is to produce a spatial listening impression. It is also possible to adapt the duration and the seat speaker audio signals further based on information from a head tracking system which tracks and determines the listening posture of the listener.

[0125] By means of the described techniques, a seat-centered sound field can be generated in front of, to the left and right of, and around the listener. By means of a dipole configuration of the speaker arrangement, a spatial listening experience can be provided with reduced computational effort and in combination with seat speakers. For example, a phantom image can be generated in the middle (0°) in front of the listener, and a sound field can be generated that extends left and right in front of the listener and surrounds the listener (+-180°). In other words, the sound field can provide a sound surround for the listener, wherein the sound field extends around the listener, and the center of the sound field is perceived as the middle in front of the seat position.

[0126] The seat speakers in the seat speaker pair can be arranged in the near field and / or diffuse field relative to the head position simultaneously or separately. The distance between one or both speakers and the listener, or the position of the typical listening posture of the listener, can be less than 1m, preferably less than 0.5m, or more preferably less than 0.3m. It is understandable to those skilled in the art that other distances between the speakers and the listener are also possible.

[0127] It is also conceivable that the duration during the playback of the audio signal is changed (in stages or continuously) and the first and second seat loudspeakers are actuated using the seat loudspeaker signals generated with the changed duration. Here, for example, head tracking information can be taken into account.

[0128] In summary, the disclosed technology is based on the following findings. A compact center speaker array consisting of at least two center speakers generates a dipole radiation characteristic with movable zero points by inversion and time delay of audio signals. These zero points can be directed specifically toward the head area of ​​the listener on the side of the ears. As a result, a reduced sound pressure is generated in this area. As a result, for each listener, the perception of the center point of the sound source of the virtual sound field is centered in front of his head. An impression of a personalized sound field centered on the seat position is generated. The seat speakers arranged around the head area respectively supplement this effect through spatial sound surround. Its decorrelated audio signals with reverberation effects produce an immersive feeling. The combination of these two components - the center sound map caused by zero point coverage and the spatial sound surround caused by the near-field speakers - uses a central virtual field and an immersive sound environment to cause an improved sound experience.

Claims

1. An audio system for generating a virtual sound field in the interior space of a vehicle, comprising: a loudspeaker array comprising at least a first and a second central loudspeaker, the loudspeaker array being arranged laterally in the vehicle interior between a first vehicle seat and a second vehicle seat, a pair of seat speakers in each of the two vehicle seats, wherein a respective pair of seat speakers is arranged in each of the two vehicle seats such that an ideal head area of ​​a person sitting in the respective vehicle seat is arranged between the respective pair of seat speakers, a signal processing unit connected to the speaker array and the seat speaker pair and providing an audio signal to the speaker for generating a sound signal, The signal processing unit is configured to: - receiving an input audio signal; -Based on the processing of the input audio signal, the first center speaker is controlled by a first center audio signal, and the second center speaker is controlled by a second center audio signal which is inverted and delayed relative to the first center audio signal, whereby the first zero point in the radiation characteristics of the sound signal of the speaker array is not centered but is moved laterally to reach the ideal head area of ​​the first vehicle seat.

2. The sound system according to claim 1, wherein: The zero point reaches the ideal head region in the vicinity of an ear of a person sitting on the first vehicle seat, which ear faces the other vehicle seat when the viewing direction of both persons on both vehicle seats is the same.

3. The sound system according to claim 1, wherein: The seat speaker is a headrest speaker which is arranged centrally in the headrest of the first vehicle seat with respect to the ideal head area.

4. The sound system according to claim 1, wherein: The first and second center speakers are arranged in a compact spatial configuration, wherein the distance between the speakers is less than 50% or 25% or 10% of the diameter of one of the center speakers, or wherein the center speakers are arranged directly adjacent to each other.

5. The sound system according to claim 1, wherein: The first center speaker and the second center speaker respectively include mid / high frequencies, in particular have the same frequency range and the same radiation characteristics, and are arranged in a dashboard or a roof panel of the vehicle.

6. The sound system according to claim 1, wherein: The first center audio signal and / or the second center audio signal comprises an audio signal related to an input audio signal.

7. The sound system according to claim 1, further comprising: Based on the processing of the input audio signal, the seat speakers of the seat speaker pair are actuated by means of corresponding seat speaker audio signals, wherein the first and second seat speakers of the seat speaker pair are actuated without a time delay with respect to one another.

8. The sound system according to claim 7, wherein: The seat speaker audio signal includes an audio signal that is decorrelated with the input audio signal and / or with the center audio signal.

9. The sound system according to claim 7 or 8, wherein: The seat speaker audio signal comprises an audio signal provided with reverberation based on an input audio signal and / or a center audio signal.

10. The sound system according to claim 1, wherein: The first head region is arranged in a left hemisphere of the speaker array and the second head region is arranged in a right hemisphere of the speaker array, and the center of the compact speaker array is arranged on a longitudinal axis between the first head region and the second head region.

11. The sound system according to claim 1, wherein: The first zero point of the speaker array is at least partially located in a side area pointing toward the center of the first head area, and the second zero point of the speaker array is at least partially located in a side area pointing toward the center of the second head area, and the second zero point is symmetrical to the first zero point about a speaker axis, and the speaker axis extends through the center of the first and second center speakers.

12. The sound system according to claim 11, wherein: The speaker axis extends between a first vehicle seat and a second vehicle seat.

13. The sound system according to claim 1, wherein: The first center speaker and the second center speaker are arranged on a longitudinal symmetry axis relative to the center of the first and second head regions.

14. A method for generating a virtual sound field in a vehicle interior space based on an audio system, the audio system comprising the following components: a loudspeaker array comprising at least a first and a second central loudspeaker, said loudspeaker array being arranged centrally in the vehicle interior between a first vehicle seat and a second vehicle seat, - a pair of seat speakers in each vehicle seat, wherein: In each vehicle seat, a corresponding pair of seat speakers is arranged such that an ideal head area of ​​a person sitting on the vehicle seat is arranged between the corresponding pair of seat speakers, a signal processing unit connected to the compact speaker array and the seat speakers and configured to receive an input audio signal and based thereon provide a corresponding audio signal to the speaker for generating a sound signal; The method is performed by the signal processing unit and comprises the following steps: - receiving an input audio signal; -Based on the processing of the input audio signal, the first center speaker is controlled by the first center audio signal, and the second center speaker is controlled by the second center audio signal which is inverted and delayed relative to the first center audio signal, whereby the first zero point in the radiation characteristics of the sound signal of the speaker array sound is not centered but moved laterally to reach the ideal head area of ​​the first vehicle seat.

15. A vehicle comprising the sound system according to claim 1.

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