A SOUND OUTPUT UNIT AND A METHOD OF OPERATING IT

Abstract

A system and a method for outputting sound where one or more first sound outputting units are identified and other, second, sound outputting units define a sound delay in accordance with the relative positions between each sound outputting unit and the first sound outputting unit(s). Microphones may be added to e.g. determine the amount and positions of persons.

The system may also use Intelligent cameras to determine number of people their position the room face direction and age distribution in order optimize audio level and equalisation of the frequency response—like in a church with many elder people or in a young audience at a live concert.

Claims

1. A method of operating a plurality of sound output units positioned in a room, space or venue, each sound output unit comprising: a position determining element, an audio signal input, a sound generator, and a signal delay circuit configured to set a delay between the audio signal input and the sound generator, the method comprising: identifying one or more first sound output unit(s) of the plurality of sound output units, determining, for each of one or more second sound output units, not comprising a first sound output unit, and by the positioning determining elements of the first sound output unit(s) and the second output unit: a relative distance from the pertaining second sound output unit to the first unit(s) and, based on the distance, a delay setting of the signal delay circuit of the pertaining second sound output unit.

2. A method according to claim 1, further comprising the step of determining a direction of the second sound output unit(s).

3. A method according to claim 1, the method further comprising the step of receiving, by one or more microphones, sound from surroundings of at least one of the second sound output units.

4. A method according to claim 1, further comprising the step of estimating, based on the sound received, a number of persons in the surroundings of the second output unit(s).

5. A method according to claim 1, further comprising the step of rotating one or more second sound output unit(s).

6. A system comprising a controller and a plurality of sound output units, each sound output unit comprising: a position determining element, an audio signal input, a sound generator, and a signal delay circuit configured to set a delay between the audio signal input and the sound generator, the controller being configured to identify one or more first sound output unit(s) of the plurality of sound output units, each of one or more second sound output units of the plurality of sound output units, not comprising a first sound output unit, being configured to: determine, based on an output from the positioning determining elements of the first sound output unit(s) and the second output unit, a relative distance from the pertaining second sound output unit to the first unit(s) and determine, based on the distance, a delay setting of the signal delay circuit.

7. A system according to claim 6, wherein at least one of the second sound output units comprises a direction sensor.

8. A system according to claim 6, wherein at least one of the second sound output units comprises one or more microphones.

9. A system according to any of claim 6, wherein the position determining element is detachable from the sound generator.

10. A sound output unit for use in the system according to claim 6.

Description

[0092] In the following, preferred embodiments will be described with reference to the drawing, wherein:

[0093] FIG. 1 illustrating a system according to the invention for delivering sound from a stage,

[0094] FIG. 2 illustrates a first embodiment of a sound output unit according to the invention,

[0095] FIG. 3 illustrates a second embodiment of a sound output unit according to the invention, and

[0096] FIG. 4 illustrates a map of sound pressure.

[0097] In FIG. 1, a stage 12 is illustrated as is a number of sound output units 14, 16, 18 and 20 for outputting sound from signals received from the stage.

[0098] Sometimes, the units 14 and 16 suffice to deliver a suitable sound pressure in the venue. Sometimes additional units 18 and 20 may be required positioned further into the crowd to be entertained. Sometimes additional units are required.

[0099] However, when multiple units can be heard by the same person in the audience, it is desired that the two units are synchronized to not hear an echo or experience phase problems. In practice, this means that the sound from the closest unit is delayed compared to that from the unit farther away, so that the sound from both units reaches the person at the same time.

[0100] Sound delay is set electronically in a unit by varying parameters of a circuit thereof between the audio input and the sound generator.

[0101] In FIG. 2, a sound output unit 14 is illustrated which has a sound generator 22 and electronics 26 configured to receive the audio signal and feed an electrical signal to the sound generator 22. The electronics 26 may comprise an amplifier, an equalizer and/or other filters for imposing adapting a signal before feeding a corresponding signal to the sound generator.

[0102] In addition, the unit 14 comprises a position determining element 28 which in FIG. 2 is an integral part of the unit 14. The element 28 comprises communication capabilities, such as an antenna, configured to communicate with other positioning determining elements. The positioning determining element 28 may additionally be configured to output a signal to the electronics 26 for controlling a delay caused by the electronics 26. In this situation, the audio signal for the unit may be received as described in relation to FIG. 3.

[0103] The position determining element may additionally be configured to, itself, receive the audio signal to be output from the sound generator. Then, the position determining element may itself generate or impose the determined delay, so that the signal output of the position determining element is already delayed. The position determining element may also comprise any amplifiers, filters or the like, so that the signal output of the position determining element may be fed directly to the sound generator.

[0104] The position determining element 28 may alternatively (see FIG. 3) be detachably attached and may have an audio signal output configured to be connected to an audio signal input 24 of e.g. a standard loudspeaker. Then, an audio signal may be fed, such as streamed, to the element 28 which may then feed the signal to the input 24. In this situation, the electronics 26 may be provided in the loudspeaker, or the operation of the electronics 26 may be handled also in the element 28, so that the unit 14 without the element 28 may be a legacy loudspeaker.

[0105] Naturally, the element 28 but also all of the unit 14 may be battery operated. Alternatively, power may be derived from e.g. a cable connected to the input 24 if provided and desired.

[0106] The operation of the system and sound output unit is that one or more sound output units is/are identified. Distances or even relative positions between the individual sound output units are determined using the positioning determining elements 28 and the delays are set in the individual sound output units so that the sound emitted from a non-identified sound output unit is synchronized with the sound output from the identified sound output unit(s).

[0107] If multiple sound output units are identified, a reference position may be determined at a position between these units and the delays set based on the distance or relative position from that position to a sound output unit. In one situation, two units positioned on either side of a stage are identified where after the delays are set in accordance with a position on the stage.

[0108] The positioning determining elements 28 may operate on radio waves and time-of-flight measurements between positioning determining elements 28. Time of flight may be determined using e.g. 2.4 GHz transmission with FLRC or LoRa modulation, which may also be used for transmitting the actual audio signal as well as carrying additional data, such as settings, distances, positions, sensor output and the like.

[0109] Based on such determination, all positioning determining elements may know their relative position to other positioning elements and thus determine the delay.

[0110] Often, one or more positioning determining elements or units 14 may be determined at or close to the desired source of the sound or the starting point of desired sound propagation. In one situation, the source of the sound is a stage on which one or more artists perform or one or more speakers speak. In other situations, a position in or around a center P of an area or a crowd may be identified (see FIG. 1). In a further situation, another element may be identified, such as a microphone used by an artist, such as on the stage. Thus, as the artist moves around, including in the audience, the delay will follow this position.

[0111] A sound generating unit or a positioning determining element may be identified by operation of e.g. a push button or the like on the unit or element. A bi-stable element thus may have a “master” setting and a “slave” setting, for example.

[0112] Alternatively, a separate controller 40, which may be handheld, may be used for identifying one or more unit(s) or element(s). The units and elements may communicate to determine relative distances and/or positions, which may be represented on a map or other illustration in which the controller may identify one or more units or elements. This identification information may then be output to the units or elements and the delays set accordingly.

[0113] An example of a map is seen in FIG. 4 in which the sound output units are indicated as squares with arrows indicating the direction of emission of sound and where an area A is illustrated in which the sound pressure is above a predetermined threshold. An area B is also indicated in which the sound pressure is lower than the same or another threshold limit. Thus, it may be desired to add a unit directing sound to the area B or to move and/or rotate the unit to the lower left so that it emits sound toward the area B.

[0114] This knowledge may be used for other purposes also, as will become clear below.

[0115] A number of additional functionalities may be incorporated in the unit 14 or the element 28, such as a directional sensor, such as a sensor capable of estimating a sound output direction of the sound generator 22, or a predetermined direction of the housing of the unit 14, relative to either other units or in relation to a predetermined coordinate system, such as the earth. The directional sensor may thus be a compass or a directional antenna capable of not only receiving a signal from another unit but also to determine a direction of such received signal.

[0116] On the basis of an output of a directional sensor, the unit 14 may estimate its angle or direction relative to a desired direction, such a direction toward or away from a position, such as an identified unit or a position between a number of identified units. The unit 14 may determine whether it needs to rotate. Rotation may be a physical rotation of the unit, such as relative to a stand or rig supporting it. Clearly, this rotation may be remote controlled and caused by one or more actuators of the unit or stand/rig. Alternatively or additionally, rotation may be a rotation of sound output direction using a phased array of sound generators.

[0117] A direction may be fed to a processor 40 which may determine a sound pressure or sound intensity map of the scene or venue by overlapping the sound output directions and potentially sound intensity function of each unit 14. Then, it may be determined that the sound intensity at a position is not sufficiently high but that this may be corrected by rotating one or more units to a direction toward or closer to the position. Alternatively, the analysis may reveal that one or more additional units is/are required. Also, the position and direction of this/these may be determined.

[0118] In addition or alternatively, an emission angle of the sound output may be altered. This is rather simple using phased arrays but is also possible using mechanical horns and the like in standard sound generators. This angle may also be taken into account when making the above map and may be altered to arrive at the desired sound intensity map.

[0119] In a particularly interesting embodiment, the unit 14 comprises one or more microphones. A microphone may be used for sensing the sound output intensity of the sound generator of the unit 14 to e.g. ensure that the sound output intensity does not exceed a maximum value.

[0120] A microphone may also be used for determining a sound output intensity from another unit outputting sound toward the unit with the microphone. In this manner, the sound intensity coverage of the scene or venue may be estimated or corrected.

[0121] A microphone may additionally or alternatively be used for detecting or quantifying sound reflections from e.g. solid structures such as walls, buildings, ceilings or the like. This information may be used for determining a distance to such structures and/or for correcting the sound output of the unit, such as by settings in the electronics 26. Additionally or alternatively, the information may be fed to the controller 40 for use in an analysis or planning of the sound providing to the area.

[0122] Microphones may also be used for other purposes. In one situation, the output of the microphone may be used for detecting sounds other than that output from the unit(s) 14, such as noise, persons or the like. The microphone may then be used for generating a signal which may be used for estimating the number of persons in the vicinity of the unit 14. If multiple microphones are present, such as one or more directional microphones, also positions of such persons may be estimated. Then, it may be estimated whether it would be desirable to rotate the unit or the sound output thereof in order to direct the sound toward one or more persons not positioned directly in front of the sound generator 22.

[0123] The number of persons or the amount of noise may also be used for estimating whether the sound output intensity should be increased or lowered. If the amount of noise or number of persons is lower than expected, the sound intensity may be higher than desired, and if the persons make more noise than expected, it may not be possible for everybody to hear the output of the units 14 with the desired sound pressure, so the sound intensity output may be increased. If a person comes too close to the unit 14, the sound intensity may also be reduced to not cause damage to that person's hearing.

[0124] Also, it may be desired to use the units 14 as sound receivers. If used at a convention or speech, the units 14 may be used as microphones to pick up questions from the audience. If multiple units 14 have microphones, a microphone array is generated which may be used to focus the sound reception from a particular position in the audience and thereby reduce the noise generated from other participants. This may be obtained by combining the sound received from multiple units and add the required delays to arrive at the operation of a directional microphone.

[0125] Clearly, such microphones may also be used for surveillance or monitoring of large crowds. Distress calls or agitated yelling may be detected and the position thereof determined, so that assistance may swiftly be directed to the location.

[0126] Thus, one or more microphones may be provided in the unit. Naturally, the microphone(s) may be provided at the desired positions of the unit depending on the desired operation thereof. If it is desired to determine the sound pressure from another unit, the microphone may be provided oppositely to the sound generator, such as at position 34. For crowd surveillance, sound pickup from participants, wall detection or the like, the positions 30 and 32 on the sides of the unit 14 may be desired. Also, a microphone may be directed in the same general direction as the sound generator 22. Clearly, all such microphones may be provided in the element 28 for easy handling and incorporation.