The present invention is within the domain of multichannel sound systems and specifically in enabling and controlling individual sound zones to provide user selected sound channels to be rendered in a selected zone. The creation of personal sound zones relies on simultaneous generation of mutual dependent sets of 3D spatial confined regions of high sound pressure (a bright zone) and low sound pressure relative to the bright zone (a dark zone). Two examples of zone configurations are given in Fig. 0a but not restricted to these scenarios.

Technologies of this type may be seen in US2013/0230175 and WO2014/036121. Adequate separation of the bright and dark zone(s) in terms of acoustic contrast should be defined e.g. according to perceptual threshold values, as disclosed by the applicant in

[US20130230175] .

The general setup procedure includes thorough pre-analysis of the specific 3D listening space by means of microphone array measurements and head and torso simulator (HATS) binaural impulse room response measurements according to [US 8,175,286 B2] . In addition, prediction of the sound field using sound field extrapolation algorithms and advanced simulations is also applied.

The system configuration procedure implicates particular processing steps in relation to the pre-analysis as illustrated in Fig. Ob. A first aspect of the invention is a method for creating and controlling personal sound zones in a closed space which is enabled with a plurality of loudspeaker transducers where the method is characterized by: o The creation of personal sound zones relies on simultaneous generation of mutual dependent sets of 3D spatial confined regions of high sound pressure (a bright zone) and low sound pressure relative to the bright zone (a dark zone);

o Adequate separation of the bright and dark zone(s) in terms of acoustic

contrast is defined according to perceptual threshold values;

o A data model of the acoustical characteristic in the closed space is generated: a thorough pre-analysis of the specific 3D listening space by means of microphone array measurements from one or more signal sources; prediction of the sound field using sound field extrapolation algorithms and simulations is applied;

o The data model includes a set of parameters and actual values that depicts the acoustical properties of the target space e.g. being a car cabin.

In a second aspect of the invention the data model include results from in situ measurement of the acoustic transfer function between every loudspeaker transducer to a 3D grid of points defining a volume larger than a human head in a cubic grid of side length 5 cm.

In one embodiment, the data model include results from in situ measurement of the acoustic transfer function between every loudspeaker transducer to a 3D grid of points defining a volume larger than a human head in a cubic grid of side length 5 cm. ID or 2D grids or patterns may also be used, and in general the distance between the points may be any distance, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 cm.

In one embodiment, a number of low frequency transducers, with the frequency range 20 - 300Hz, for example, are distributed around target zones and/or with single control loudspeakers in or nearby one or more of the target zones. Naturally, the frequency range may vary. The lower end of the interval may be 10, 15, 20, 25, 30, 35, 40, 45, of 50Hz or the like, and the upper value of the interval may be 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, or 500 Hz, for example.

In one embodiment, a number of mid frequency transducers, with the frequency range 200- 7000 Hz are mounted on front seat(s) orientated towards target zones at the rear seat(s) or mounted in ceiling angled towards the head of the listener(s). The lower end of the interval may be 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, or 500 Hz, for example. The upper end of the interval may be 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500 or 10000Hz for example.

In one embodiment, one or more high frequency transducers, with the frequency range 7000 - 20000Hz are directed to the centre of one or more of the target zones. The lower end of the interval may be 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500 or 10000Hz for example. The upper interval may be 10, 12, 14, 15, 16, 18, 20, 22, 25 or 30 kHz for example. In one embodiment, the data model includes the Acoustic Contrast Control that represents the energy cancellation approach, and the ratio of the spatially averaged sound pressure levels between the bright zone and the dark zone is maximized.

In one embodiment, the data model includes definitions of one or more loudspeaker arrays configured to have the directional radiation towards individual target zones.

In one embodiment, the data model includes definitions to obtain binaural sound reproduction caused by two different lobes of high sound pressure aiming towards left and right ear respectively.

In one embodiment, the data model includes definitions of one or more loudspeaker arrays configured to have the sound field control towards individual target zones.

In one embodiment, sound zone filters are represented in algorithms as a finite impulse response filter.

In one embodiment, sound zone filters are procedures referred to by the data model as external constraints.

In one embodiment, a defined perceptual model is referred to by the data model.

In one embodiment, the data model of the acoustical characteristic in the closed space is generated though also measurements made by a head and torso simulator (HATS) binaural impulse room response measurements;

In the following, preferred embodiments are described with reference to the drawing, wherein:

Summary of Figures

Figure 0 displays the zone concept and pre-analysis steps Figure 1 displays reproduction of bass frequencies Figures 2 and 3 display reproduction of midrange frequencies Figure 4 displays reproduction of high frequencies Figure 5 displays the System Overview of one embodiment of the invention

Figure 6 displays the Constraint Solver of one embodiment of the invention

Figure 7 displays a sound zone configuration example

Figure 8 displays a 3D microphone arrangement In a preferred embodiment reproduction methods are adjusted according to transducer frequency domain.

Reproduction method - bass frequencies

FREQUENCY RANGE: approx. 20-300 Hz

SOURCE LAYOUT: 4-8 loudspeakers (woofers) distributed around target zones and/or with single control loudspeakers in or nearby one or more of the target zones. All loudspeakers receive signals that are radiated in all target zones.

TARGET: the creation of one zone of high sound pressure level (bright zone) simultaneously reproduced with another zone of low sound pressure level (dark zone) relative to the bright zone; a zone being a 3D spatially confined region, that is larger than a human head, within an enclosed space in which monaural sound is reproduced.

CONTROL METHOD: Acoustic Contrast Control represents the energy cancellation approach, and the ratio of the spatially averaged sound pressure levels between the bright zone and the dark zone is maximized. The phase of the resulting sound field is not taken into account. The implementation of the control method is augmented with a number of performance related measures to improve the "quality" of the target for filter calculation. Alternative hybrid methods are described in [PCT/EP2014/050081] and [WO 2013/135819] which are hereby incorporated by reference.

SETUP: In situ measurement of the acoustic transfer function between every loudspeaker to a ID, 2D or 3D grid of points defining a volume larger than a human head in a cubic grid of side length of e.g. 5 cm. Advanced pre- and post-processing schemes may be introduced in the calculation of the filter for each loudspeaker.

Reproduction method - midrange frequencies FREQUENCY RANGE: approx. 200-7000 Hz SCENARIO #1 : DIRECTIONAL RADIATION

SOURCE LAYOUT: 2x(7+2) loudspeakers mounted on front seat orientated towards target zones at the rear seats or mounted in ceiling angled towards the head of the listener.

Individual array and signal flow in front of each target zone.

TARGET: Focusing of the sound field generated by each array towards the respective target zones. Each array distributes high energy towards the centre of the zone and attenuates the sound field towards the centre of the car compartment and side windows. Each zone is controlled by a specific array individually. CONTROL METHOD: Acoustic Contrast Control, and/or least mean square optimization of the directivity and/or spatial sound field. Optimization made either based on anechoic measurements in the cube (directivity control) or utilizing in situ measurements (sound field control) .

SETUP: Directional radiation measurements of arrays measured on e.g. a half circle with radius equal to target distance and/or in situ measurement of the acoustic transfer function between every loudspeaker to a ID, 2D or 3D grid of points defining a volume larger than a human head in a cubic grid of side length of e.g. 5 cm or a ID, 2D or 3D grid of points sampling volume around each ear of the target listener.

VARIATIONS: when each array produces two different lobes of high sound pressure aiming towards left and right ear respectively, binaural sound reproduction methods can be introduced, as illustrated in fig. 2.b.

Reproduction method - midrange frequencies

FREQUENCY RANGE: approx. 200-7000 Hz

SCENARIO #2: SOUND FIELD CONTROL SOURCE LAYOUT: 2x(7+2) loudspeakers mounted on front seat orientated towards target zones at the rear seats or mounted in ceiling angled towards the head of the listener and a spatial 3D distribution. All loudspeakers receive signals to all target zones. TARGET: Optimization of the sound field generated by the total amount of loudspeakers towards the respective target zones.

CONTROL METHOD: Acoustic Contrast Control, and/or least mean square optimization of the sound field. The implementation of control method is augmented with a number of performance related measures to improve the "quality" of the target for filter calculation.

SETUP: In situ measurement of the acoustic transfer function between every loudspeaker to a 3D grid of points defining a volume larger than a human head in a cubic grid of side length of e.g. 5 cm or a ID, 2D or 3D grid of points sampling volume around each ear of the target listener. Advanced pre- and post-processing schemes may be introduced in the calculation of the filter for each loudspeaker.

Reproduction method - high frequencies

FREQUENCY RANGE: approx. 7000-20000 Hz

SOURCE LAYOUT: a single lens aiming towards the centre of the target zone or two lenses aiming towards each ear of the listener in each target zone for binaural reproduction. The width of the main lobe is optimized for each purpose individually.

TARGET: Passive control of the directivity of a single loudspeaker (tweeter) in order to focus energy towards the target zone and attenuate leakage sound energy towards the other zones and side windows.

CONTROL METHOD: 3D geometry optimization of acoustic lenses and influence of baffling. SETUP: FEM simulation optimization and verification in situ. In further aspects of the invention the data model may be:

• The Acoustic Contrast Control that represents the energy cancellation approach and the ratio of the spatially averaged sound pressure levels between the bright zone and the dark zone is maximized.

· Definitions of one or more loudspeaker arrays configured to have the directional radiation towards individual target zones.

• Definitions to obtain binaural sound reproduction caused by two different lobes of high sound pressure aiming towards left and right ear respectively. • Definitions of one or more loudspeaker arrays configured to have the sound field control towards individual target zones.

In yet other aspects of the invention: · The sound zone filters are represented in algorithms as a finite impulse response filter.

• The sound zone filters are procedures referred to by the data model as external

constraints.

• A defined perceptual model (ref PA 2014 00083; included by reference) is referred to by the data model.

Parameters that interact via relations, and are partly or fully included in the data model :

• Acoustic contrast

• Reproduction error

• Planarity

· Seat/zone configuration

• Loudspeaker layout (location and type)

• Privacy (VIP teleconference) - masking of sound events

• In-car communication

• Occupancy

· Audio programme

• Sound imaging / staging (Binaural reproduction / Stereo / surround sound)

• Velocity / RPM of vehicle engine

• External (road) noise

• Internal noise

· Reproduction level

• Equalization (e.g. "mood")

• Ambient conditions (e.g. temperature and static pressure)

• "room gain" - adaptation to environment

• Loudspeaker driver condition (e.g. voice coil temp., linear range)

In the preferred embodiment the data model is implemented as a constraint model in terms of a table.

This constraint table can be accessed by a constraint solver to deduce legal combinations that constitute one or more configurations of system components being at least: media sources, sound transducers, amplifiers, equalizers. As room temperature may influence the acoustical properties in a room, different temperature intervals may be included as parameters in the constraint data model. Thus, the initial (usually 3D) analysis of the room preferably is executed in different temperature conditions, with the result to be applied at run time to address legal adjustment parameters accordingly.

In the preferred embodiment, a constraint solver handles parameters/variables of different types:

• Boolean with a values set like On/off, True/false, Logical "1 or 0"

• Integer, e.g. "10"

· Integer intervals, e.g. "0 to 100"

• Real, e.g. "12.88"

• Real intervals, e.g. "17.5 to 21.5"

• Symbolic, e.g. "Left", "Right" "Centre" The attributes per variable are defined and interpreted as enumerated options, like: One sound channel is defined : "Channel: Attrib(Left, Right, Centre)". Numeric are defined and interpreted individually or in intervals, like: Amplifier levels is defined: "AmpLevel: Integer (0, 1, 2, 3, 4, 5)", or

"AmpLevel: Integer (0 -> 5)".

A defined variable may be a candidate for a resource calculation and/or an optimization procedure according to a specified performance requirement.

This enables an implicit cost function to be enabled when a certain combinations of variables included in the solution space for the legal combination in which the addressed parameter is part.

An equation may interact with the constraint table variables in alternative modes of operation:

Examples of a set of generic constraint tables, in which an equation Zx is addressed, are: Constraint table 1 :

PI and P2 and P3 and P4 and Zl Or (PI and P5 and P6) Or (P7 and P8) Constraint table 2:

PI and P2 and P3 Or (PI and P5 and P6) Or (P7 and P8) and Z2 An example of an equation is: Zl= PI + P2 + n*P3 In which the variables P1,P2,P3

• are selectable as input/output parameters in the constraint table;

• are included as variables in the calculation, and with the result Zl;

• and Zl is input/output parameter in the constraint table.

Thus:

P1,P2,P3,P4 may be selected unconditionally if the Zl variable is unselected/uncalculated.

P1,P2,P3 variable values will be constrained if Zl has been selected/calculated.

Alternative values for one or all of the P1,P2,P3 might be forced which may imply that Zl to be recalculated as the constraint table to be reevaluated.

Another example of an equation is: Z2= PI + P4 in which the variables P1,P4 are from different constraint tables. Thus, the processing is in principle as disclosed above, just including the two constraint tables to be reevaluated in parallel.

Figure 5 displays a preferred System Overview, in which there are two functional entities and related subsystems: a) Analyze & Simulate and b) Run Time environment. Analyze and Simulate is the subsystem applied to analyze the space (room) of the target, e.g. a car cabin:

• The system is operated based on functional requirements, specifications and

parameter pre-sets, defined for the current application, being e.g. a car audio/video rendering system including individual sound zones enabled as 3D-sound spaces and rendered via a multi-channel audio system.

• The acoustical characteristics and the behavior of the specific target space is analyzed via an advanced robotic system enabled with a plurality of microphones and sound signals, that automatically scans the space, and identify one set of parameters for this specific target.

The parameters are according to the requirements defined for e.g., but not limited to: the number of passengers and location in the car, positions of the heads of the passengers, the number and location of sound channels (transducer units), the number and placement of sound zones, type of media (music/speech) and alike.

• The result of the Analyze and Simulate function is a complete parameterized data model including combination of parameters that define the "state space" for one actual target (room) enabled with: a physical configuration, a number of sound channels (transducers), one or more listeners, one or more sound zones, one or more of 3D sound spaces, sound zone characteristics (gain, threshold limits).

• The parameterized data model is converted (compiled and compressed) and mapped into a constraint table that relate any relevant parameter with any other relevant parameter. The structure of the table being an n-dimensional state space with direct real time access to any of the defined parameter combinations.

Run Time is the subsystem applied to control the acoustical system functionality in the room of the target, e.g. a car cabin:

• Based on the sensor readings and other inputs (user given of system generated) the acoustical parameters are controlled via stimuli to the system hardware. This, as example, to select an audio source, and request a specific sound zone configuration, and provide it to the user at a certain volume level. • The audio system is reconfigured dynamically according to the defined constraints/relations via the Deduce function, that communication with the relation via the state vector, which acts as an input/output list of parameters and their attributes.

· Certain problem domains may include an optimize function, in which a linear

constraint or formula is computed.

• Media information as channels or streams with audio, video or tele is accessed via the local devices or virtual sources residing on the Internet or in the Cloud.

Figure 6 displays the concept of the constraint solver, and how this interrogates with the application.

The State Vector (20) is the data interface that connects the system parameters to the application program (22).

The system parameters include input values from physical sensors, user given commands and control commands from utility software.

The system parameters include output values to be applied for setting actual variables as deduced (23) from the defined constraints (21). The constraints define a solution space including legal combinations according to the defined relations; thus the solution space is consistent and complete and without any contradictions. In a preferred embodiment the sequence of processing is:

• The state vector is initialized with preset values.

• A change of the state in the State Vector [SV](20), e.g. a user triggered

command/event generates new inputs into the SV.

• The application (22) accesses the SV via the Deduce function (23) which interrogates with the Constraints to determine the consequence of the given input as validated against the defined parameter relations.

• The consequence of this deduction might be new parameter values and updates of the SV accordingly.

• As required in actual application additional constraints, represented in linear

constraints, procedures or formulas might be supported; this supported via the

Optimize function (24). Figure 7 displays an example of a multi-channel sound system including five loudspeaker transducers, each having individual controllable amplifier-, equalizer-, and delay means. The system is configured according to the invention to be enabled with two sound zones for the pleasure of two users. The configuring procedure transforms the physical domain to a virtual sound space enabled access and control by a user.

The basic primitives for the configuring are, but limited to:

• The number of the sound zones to be configured;

• The physical location Χ,Υ,Ζ relative in a room/space of the zones;

· The threshold, i.e. acceptable interference, among the one or more zones;

• The type of sound source, e.g. speech or music, which is selected to be rendered in a selected sound zone;

• The number of sound transducers and type (tweeter, midrange, woofer);

• The physical location Χ,Υ,Ζ relative in a room/space of each of the transducers;

· The characteristics for each amplifier-, equalizer-, and delay means.

• The characteristics of the Χ,Υ,Ζ room/space, like: size, acoustical impedance, room gain, reflections, isolation, reverberations and alike in given positions.

Figure 8 displays the concept of a 3D microphone arrangement (30). A plurality of microphones are installed in mechanical support means that constitute a 3- dimensional grid (30) within which one or more microphones can be positioned relative to a given X,Y and Z position in a 3D coordinate system.

A number of microphones, e.g. five are considered as a set, which is fixated at the same mean. In a preferred embodiment the movement of a set of microphones (36,37,38,39) are enabled with slider means to move along the X axis (35); e.g. one set of microphones is slide from one position (36) to another position (37), or moved from one level/height (38) to another level/height (39).

The grid arrangement is arranged with a number of levels/heights e.g. three (31,32,33) . The movement/slide of the set of microphones may be manually operated or partly or fully motorized. The physical dimensions of the 3D microphone arrangement, are determined by the closed room dimension to analyzed and the required to precision of the measured acoustical parameters.

An application example having a car cabin, which must be in defined in 3D cube grid of side/length 5cm, the dimension are: number of microphones in a set is 20, length along the X-axis, approx. 2.5m, width along the Z-axis approx. 1.5m, and height along the Y axis being in three layers 10cm.

The invention is very applicable in advanced multi channel sound systems in which individual sound zones are desired; such as in closed spaces/room in cars, houses, boats, airplane and alike.

The control systems may include means for adaptive configuring and reconfiguring of sound zones and where the control is based on the information residing in the data model include relations among parameters, and where the data model is accessed by a constraint solver that deduces legal solutions according to control inputs given by e.g. : the user, sensor readings, system software generated events, application generated events and alike.