EP1371264A1

EP1371264A1 - Method and device for operating a sound system

Info

Publication number: EP1371264A1
Application number: EP02719647A
Authority: EP
Inventors: Helmut Wörner
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-17
Filing date: 2002-02-28
Publication date: 2003-12-17
Also published as: DE10113088A1; WO2002076149A1

Abstract

The invention relates to a method and a device for operating a sound system, whereby signals which are emitted from an analog signal source are amplified, transmitted to the individual loud speakers in a sound system and emitted therefrom. The aim of the invention is to produce a method or a device for operating such a sound system which can reduce the cost of the equipment considerably in a simple manner and which offers simpler and less expensive possibilities for controlling the sound thus emitted, in addition to better control of ambient noise. According to the invention, the signals from the signal source (5) are digitalized and transmitted via a digital network (3, 4) to interfaces (2) of individual loud speakers (1) or groups of loud speakers (1), whereupon they are evaluated, converted into analog signals and then emitted via the loud speakers (1).

Description

Method and device for operating a public address system

The present invention relates to a method and a device for operating public address systems, in which signals originating from an analog signal source are amplified and transmitted to the individual loudspeakers of a public address system and output by these. Such a public address system therefore generally has a plurality of loudspeakers which can be controlled or activated by at least one control center. However, this should also include public address systems which can not only be activated from a single control center, but which may also be controlled and put into operation from several different points. Appropriate methods and devices are well known, e.g. from airports and train stations, department stores and shopping centers, schools, office and conference buildings.

The conventional public address systems are relatively complex since they normally require complete cabling from one or more control centers, which must cover all loudspeakers. If, in addition, individual loudspeakers or loudspeaker groups are to be addressed separately from the other loudspeakers, additional control lines are required to selectively switch individual loudspeakers on or off so that an announcement is only output via part of the loudspeakers of the entire system, e.g. if this announcement is only made for a limited number of people who are in the area concerned. This is e.g. known from the individual platforms of train stations, where announcements relating to a train entering or leaving a certain platform are only made via the loudspeakers arranged along this platform.

It is understood that this causes considerable additional effort in the creation and planning of the entire speaker system. Another disadvantage is that in most conventional systems the control center has no control over whether the sound signals emitted by the loudspeakers are understandable for the persons for whom they are intended.

At train stations, for example, it is quite possible that passengers on a platform should receive information via the loudspeakers installed there, but that they cannot understand this information because, for example, a train is entering or passing on a neighboring track. However, the spokesman in the corresponding control center does not notice this. As a rule, this causes annoyance for the passengers, especially if they do not receive important information as a result, so that they may move one to another. Missing the train on the track. In other situations, loudspeakers are perceived as very annoying if they reproduce speech information or music excessively loud in relation to the ambient noise. This, too, is generally not recorded and controlled from a control center, at least in the case of large public address systems.

Although public address systems are already known in which the sound signals emitted by the loudspeakers are checked by means of microphones, and noise can also be detected, this requires considerable additional equipment outlay because the signals picked up by the corresponding microphones are amplified and routed back separately to the control center Need to become.

Compared to this state of the art, the object of the present invention is to provide a method and a device for operating such a public address system, which have a considerably lower outlay in terms of apparatus and at the same time also offer simpler and less complex options for comparing the sound output Control ambient noise better.

With regard to the method mentioned in the introduction, this object is achieved in that the signals emanating from the signal source are digitized and transmitted via a digital network to the interfaces of individual loudspeakers or groups of loudspeakers, evaluated, converted back into analog signals and via the corresponding one or more Speakers are output.

Digital networks, e.g. Parts of the telephone network, the Internet, so-called "intranets" and also smaller local networks, such as the ethernet have become almost ubiquitous in the meantime, so that in many cases one can fall back on existing networks if a suitable sound system is to be installed. In any case, however, the PA system can be combined with the construction of corresponding digital networks that also serve purposes other than PA.

It is understood that in such a public address system, as a rule, an interface should be assigned to each individual loudspeaker or also to a group of loudspeakers, at which the digitized data is recorded, optionally evaluated and converted back into analog signals, which are then transmitted via the loudspeaker in question be issued.

In addition to the previously digitized analog signals, which correspond to the originally entered sound signals, the digitized data preferably also contain digital control signals, by evaluating the decentralized loudspeakers or loudspeaker groups in a desired manner.

It goes without saying that the so-called "control center" does not have to be a single, central point, but that such a control center can be arranged at any point in this network due to the known properties of digital networks, and in particular that several different control centers in this digital one Network may be present, and of course coordination between these different control centers may have to take place in order to avoid the simultaneous output of signals from different control centers via the same loudspeakers.

The additional control information is, in particular, address information, with each individual loudspeaker or at least each interface, which may also be assigned several loudspeakers, being assigned a digital address, which is generally also referred to as an IP address (IP = Internet Protocol). An essential evaluation step in these systems is to determine whether certain sound signals are to be output at all via a specific loudspeaker or via a group of loudspeakers. This is done simply by assigning the corresponding sound signals to the respective address of the loudspeakers or loudspeaker groups via which the signals are to be output.

Other control signals can e.g. Contain information about volume and frequency-dependent amplification functions.

The loudspeakers in question are preferably active loudspeakers which have their own power supply, amplification and control system, that is to say independent of the control center. The intelligent interfaces expediently not only have an evaluation logic by means of which the control data contained in the digitized data are evaluated and implemented, but which are also capable of independently controlling the sound signals output. For example, the ambient noise occurring in the immediate vicinity of a loudspeaker or a loudspeaker group is recorded, digitized and directly in a microprocessor of the respective interface e.g. are processed in such a way that additional signals are superimposed on the sound signals to be output, e.g. sound signals that are inverse to the ambient noise.

Corresponding feedback signals, which are obtained, for example, from microphones or sound pressure meters in the vicinity of a loudspeaker or a loudspeaker group, can of course also be sent back to a control center via the digital network after digitization, which then derives the necessary control information and the volume based on the Adjust feedback signal or can also add inverse signals to ambient noise. Such a central solution is quite feasible for smaller networks, but the decentralized solution is preferable for larger networks.

The so-called MP-3 or H323 standard is expediently used for the digitized data. These standards are common and proven for the compression and transmission of digitized sound data and enable fast transmission without delay and with high quality.

Further advantages, features and possible uses will become clear from the following description of a preferred embodiment and the associated figures. Show it:

1 shows a diagram of a public address system that is controlled via a digital network and FIG. 2 shows a schematic detailed view of a loudspeaker with an associated one

Interface.

A control center can also be seen in FIG. 1, which is also referred to as a sound network management system (SNMS). This control center is equipped with a control unit that enables targeted control of specific loudspeakers or loudspeaker groups using hardware and software. This control center 5 is connected to a network 3 via an interface 6, the network 3 e.g. can be the internet or an intranet. With 4 is a local network, e.g. an ethernet. It goes without saying that the control center 5 can also be connected directly to the Ethernet 4 or that the individual loudspeakers 1 or their interfaces 2 can also be connected directly to the Internet or intranet 3.

A number of loudspeakers 1 can be seen in FIG. 1, each of these loudspeakers 1 also being able to stand for a whole group of loudspeakers. An interface 2 is assigned to each loudspeaker or each loudspeaker group, which in turn has an individual IP address. Sound signals, for example an announcement via a microphone 12, originating from the control center 5 are digitized and forwarded via the interface 6 into the network 3 and from there into the network 4. This data, which is compressed and digitized according to the MP-3 standard, for example, also contains address information by means of which individual speakers or speaker groups 1 are addressed in a targeted manner. The data transmitted on the network 4 are recorded in the intelligent interface 2 and the interface 2 checks whether the address information contained in this data means that the loudspeaker 1 assigned to it or the corresponding group of loudspeakers 1 should output these signals. If this is the case, the digitized data are converted into analog data by the interface and output via the loudspeaker 1, whereby in the digitized Data may contain other control signals, for example via the volume and timbre. The individual loudspeakers or loudspeaker groups 1 are therefore preferably active loudspeakers or else as a group they have a common amplifier which processes the analog data in accordance with the control signals. Each of the interfaces 2 expediently also contains a processor, as can be seen more clearly in FIG. In FIG. 2, the intelligent interface 2 assigned to a loudspeaker 1 is enlarged again and shown with more details. As can be seen, the interface 2 initially contains an Ethemet interface 11, on the assumption that the network in question, to which the individual loudspeakers 1 are coupled here, is an Ethernet. The data received via the Ethernet or a corresponding input are further processed in a processor 10, that is to say primarily separated according to pure sound data and control data. The sound data are forwarded to a digital / analog converter 7 and are then output by the loudspeaker 1 after appropriate amplification. A corresponding amplifier and its control by processor 10 are not shown.

A microphone 8 and a Db meter 9 are additionally provided at the interface 2, which e.g. Record ambient noise or the sound pressure coming from the speakers. The output signals from microphone 8 and Db meter 9 are or are preferably also digitized and are either processed by processor 10 or are routed back to control center 5 via the network.

The processor preferably processes this data itself, e.g. Analyzes ambient noises picked up by the microphone 8 and then superimposes additional signals on the sound signals output via the digital / analog converter, which signals correspond to the inverse of the ambient noises picked up by the microphone 8. In this way, ambient noise is suppressed and the desired sound signals emanating from the loudspeaker 1 are easier to understand. The volume of the loudspeaker 1 can be controlled via the signals measured with the aid of the Db meter 9.

The use of the MP-3 or H323 standard has the advantage that the sound signals are transmitted and transmitted with practically no time delay and in very good speech or sound quality.

The effort, that is to say the creation of a digital network, is comparatively low, especially since such digital networks are often already present anyway or only require a slight expansion or can also be used in some other way.

It is understood that the system according to the invention can also be applied to other areas, e.g. Video surveillance systems, fire alarm systems, etc. can be transmitted.

Claims

P atentans u che

1. A method for operating a public address system in which signals emanating from an analog signal source (5) are amplified and transmitted to loudspeakers (1) and emitted by them, characterized in that the signals emanating from the signal source (5) are digitized and via a digital network (3, 4) to interfaces (2) of individual loudspeakers (1) or groups of loudspeakers (1) are transmitted, evaluated, converted back into analog signals and then output via the loudspeaker (s) (1).

2. The method according to claim 1, characterized in that in addition to the digitized analog signals, additional digital control signals are transmitted to the interfaces (2).

3. The method according to claim 2, characterized in that the individual interfaces are assigned digital addresses and that the control signals contain at least one address signal.

4. The method according to any one of claims 1 to 3, characterized in that the evaluation of the signals received at the interface (2) of a loudspeaker (1) or a group of loudspeakers (1) comprises at least the decision whether the associated analog signals via the or the loudspeakers (1) assigned to this interface (2) are to be output or not.

5. The method according to any one of claims 2 to 4, characterized in that the control signals comprise information about the volume of the signals to be output from the loudspeaker (1).

6. The method according to claim 5, characterized in that the control signals comprise further sound information.

7. The method according to any one of claims 1 to 6, characterized in that the MP-3 or the H323 standard are used for the digitized data.

8. The method according to any one of claims 1 to 6, characterized in that in the environment of a speaker or a common interface assigned group of speakers (1) ambient noise and / or the outgoing from the speakers Sound recorded, digitized and processed by a local microprocessor or possibly transmitted back to a control center via the digital network.

9. Device for operating a public address system with a plurality of decentralized loudspeakers (1) which can be controlled from at least one control center, characterized in that the loudspeakers (1) are connected to the at least one control center (6) via a digital network.

10. Device for operating a public address system according to claim 9, characterized in that the digital network is the Internet, an intranet, an Ethernet or a combination of the aforementioned networks.

11. The device according to claim 9 or 10, characterized in that each speaker is assigned to a local interface and that each interface is assigned a digital address via which the speaker can be activated.

12. Device according to one of claims 9 to 11, characterized in that each loudspeaker or at least one group of loudspeakers each having a common interface is assigned a microphone which detects both ambient noise and the sound emanating from the loudspeaker in question , and that further devices are provided by which the microphone signals are digitized and transmitted back to the at least one control center.

13. Device according to one of claims 9 to 12, characterized in that each loudspeaker or each interface is assigned an evaluation logic which is able to evaluate the transmitted digitized and control signals containing signals to decide whether these signals via the or the speakers (1) assigned to the relevant interface (2) are to be output.

14. Device according to one of claims 9 to 13, characterized in that each speaker or each interface is assigned a microprocessor which, among other things, detects the ambient noise captured and digitized by a microphone and is capable of using corresponding sound signals via a sound generator to send out the speaker.

15. The device according to one of claims 9 to 14, characterized in that each speaker or at least groups of speakers each have their own power supply and are designed as active speakers. Device according to one of claims 9 to 15, characterized in that a Db measuring device is assigned to each loudspeaker or each group of loudspeakers.