Motor vehicle and methods for operating a motor vehicle

Abstract

Motor vehicle (10) with at least one sound transducer (12) designed to be operated at least temporarily in a first switching state, wherein the sound transducer (12) in the first switching state converts an acoustic signal into an electrical signal, wherein the sound transducer (12) is configured to receive, in the first switching state, an acoustic signal describing a sound source (18) external to the vehicle in an external environment of the motor vehicle (10), to convert it into an electrical signal describing the sound source (18) and to transmit the electrical signal describing the sound source (18) to a control device (14) of the motor vehicle (10), wherein the control device (14) is configured to receive the electrical signal describing the sound source (18) and to forward it to an output device arranged in a motor vehicle interior, wherein the output device is configured to receive the electrical signal describing the sound source (18) and to output it as a warning message representing the sound source (18) in the motor vehicle interior, wherein the output device has a computing unit configured to convert the electrical signal into the warning message representing the sound source (18), wherein the warning message comprises a rising and falling visual and haptic signal representing the sound source (18), wherein the vehicle-external sound source (18) is an ambulance or a police car with a siren, wherein the output device is configured to reproduce a rising and falling siren as a rising and falling light signal and as a rising and falling haptic signal visually and haptically in the vehicle interior, wherein the haptic signal comprises a vibration of a steering wheel of the vehicle, wherein the sound transducer (12) is designed to continuously receive the acoustic signal describing the sound source (18) for a dynamic live adjustment of the corresponding output in the vehicle interior.

Description

[0001] The invention relates to a motor vehicle with at least one sound transducer and a method for operating such a motor vehicle. The sound transducer of the motor vehicle is configured to be operated, at least temporarily, in a first switching state, in which it converts an acoustic signal into an electrical signal. In other words, the sound transducer can be operated as a microphone in the first switching state.

[0002] Modern vehicles typically feature effective acoustic insulation. This means that noises emitted by external sound sources in the vehicle's surroundings are often poorly perceived, or even completely inaudible, within the acoustically insulated interior. While this is advantageous because it prevents distractions from external noises, it can also create problems. For example, a vehicle occupant might not hear an approaching siren or at least be unable to accurately determine its direction of approach. Similarly, interactions with other road users can be difficult, as the vehicle's good acoustic insulation can make it hard for the occupant to hear a horn or bicycle bell, for instance.This means that the vehicle occupant or driver must rely on their visual impressions of the surroundings when navigating their vehicle. This does not contribute to increased road safety for all road users.

[0003] It is known that motor vehicles are equipped with microphones to record sounds emitted by the vehicles themselves. For example, US 2020 / 022 68 56 A1 describes a motor vehicle in which the loudspeakers installed in the vehicle can be used as microphones. These microphones can record acoustic signals generated by components of the vehicle during operation. This enables vehicle diagnostics based on sound recordings made inside the vehicle.

[0004] US Patent 9,914,391 B2 describes a motor vehicle equipped with loudspeakers designed to emit an outward-facing warning tone to announce the vehicle's approach. One of the loudspeakers can also be used as a microphone to pick up the tone emitted by the other loudspeakers and compare it to a reference tone. This ensures that the warning tone emitted by the motor vehicle always matches a predetermined reference tone.

[0005] The aforementioned solutions deal with recording and analyzing noises produced by a motor vehicle itself. This cannot contribute to an improved perception of the surroundings of a vehicle occupant.

[0006] The acoustic reproduction of external sounds within the vehicle interior is known from DE 10 2015 221 361 A1 and DE 10 2018 200 008 A1. Isolated acoustic reproduction within the vehicle interior can confuse a vehicle occupant and therefore does not contribute to improving the perception of the surroundings.

[0007] DE 43 34 890 A1 describes a motor vehicle with a sound transducer mounted on an outer surface of the vehicle's body. The sound transducer receives signals which are fed to a microprocessor which, upon matching signal patterns, generates a warning signal that is output inside the vehicle as an acoustic and / or visual signal.

[0008] German patent DE 10 2007 028 400 B3 describes a method for signaling the approach of a vehicle with right-of-way to a driver. The acoustic signals emitted by the vehicle with right-of-way are recorded and detected by a microphone. The signals are then subjected to pattern recognition and a pattern comparison with reference patterns stored in the vehicle. If there is sufficient similarity with a reference pattern, it is concluded that the signals are those of a vehicle with right-of-way. In this case, a warning is issued to the driver.

[0009] German patent DE 10 2010 022 165 A1 describes the detection of an acoustic warning signal emitted by an emergency vehicle. The vehicle is equipped with an acoustic detection unit that detects the warning signal. The warning signal is identified, and the driver of the vehicle is alerted to the presence of the emergency vehicle by the sound of a warning signal.

[0010] DE 35 35 833 A1 describes four receivers mounted on the exterior of a motor vehicle, which are used to evaluate signal levels and determine the position of an emergency vehicle. This position is then transmitted to a direction indicator in the vehicle's warning system.

[0011] It is an object of the present invention to improve the perception of the environment in a motor vehicle interior and thus contribute to increased road safety.

[0012] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments of the invention are described by the dependent patent claims, the following description, and the figures.

[0013] The invention provides a motor vehicle with at least one sound transducer. The sound transducer is designed to be operated, at least temporarily, in a first switching state, in which the sound transducer converts an acoustic signal into an electrical signal. In other words, the sound transducer can be operated, at least temporarily, as a microphone.

[0014] The transducer is designed to receive, in its first switching state, an acoustic signal describing a sound source external to the vehicle in its surrounding environment, to convert this signal into an electrical signal describing the sound source, and to transmit this electrical signal to a control device of the vehicle. In other words, the transducer is arranged on the vehicle such that it is oriented towards the surrounding environment. This allows it to receive sounds emitted by the external sound source as an acoustic signal. Preferably, several such transducers are arranged on the vehicle, and in particular, an arrangement can be chosen that provides 360-degree coverage for receiving acoustic signals from the vehicle.In other words, the motor vehicle can be equipped by the transducers of the transducer arrangement to receive sounds from all directions surrounding it as acoustic signals.

[0015] The conversion of the received acoustic signal into an electrical signal describing the sound source can occur in the transducer according to the well-known principle of electrodynamic conversion. As is known, a transducer is a device that converts acoustic signals, as alternating sound pressures, into electrical signals, for example, electrical voltage, or conversely, converts electrical voltage into acoustic signals. The transducer can operate according to the electromagnetic, electrodynamic, electrostatic, and / or piezoelectric principle.

[0016] The control device according to the invention is designed to receive the electrical signal describing the sound source from the sound transducer and to forward it to an output device located in a vehicle interior. The output device can, for example, be implemented as a vehicle information system. The vehicle information system can have various display and / or output devices that enable the output of visual and / or haptic and / or acoustic signals or information.

[0017] According to the invention, the output device is designed to receive the electrical signal describing the sound source from the control device and to output it as a warning signal representing the sound source in the vehicle interior. In other words, the output device has a corresponding communication interface to the control device in order to receive the electrical signal. The output device also has a processing unit designed to convert the electrical signal into a warning signal representing the sound source. The external sound source is an ambulance or a police car with a siren, and the rising and falling pitch of the siren is visually represented as a rising and falling light signal in the vehicle interior.Similarly, according to the invention, a haptic signal that rises and falls in volume is provided, namely a vibration of the motor vehicle's steering wheel in rhythm with the siren. The possibilities for acoustic reproduction are discussed in detail below.

[0018] The invention offers the advantage that ambient noise or acoustic signals emitted by external sound sources in the vehicle's surroundings are perceptible inside the vehicle. This advantageously increases road safety. In other words, the improved acoustic insulation of a vehicle's shell or outer skin is overcome by the inventive transmission of ambient noise into the vehicle's interior.

[0019] The invention also includes embodiments that offer additional advantages.

[0020] One embodiment provides that the output device comprises at least one loudspeaker located in the vehicle interior, wherein the control device is configured to transmit the electrical signal describing the sound source to the loudspeaker, and wherein the loudspeaker is configured to output the electrical signal describing the sound source as a warning tone representing the sound source in the vehicle interior. For example, one of the loudspeakers of the vehicle's entertainment system can be used as the loudspeaker. The processing unit of the output device described above can be configured to transmit the electrical signal received from the control device directly to the loudspeaker, so that the loudspeaker reproduces the acoustic signal emitted by the external sound source as a true-to-life reproduction of the acoustic signal in the vehicle interior.In other words, the sound reproduced inside the vehicle could be an unaltered reproduction of the external sound source. In the case of the siren described above, a warning tone in the form of a siren would be reproduced inside the vehicle. However, it is also conceivable that the acoustic signal is not reproduced accurately, but rather that the processing unit of the output device converts the electrical signal transmitted by the control unit in such a way that the warning tone representing the sound source sounds different inside the vehicle than the external sound source.

[0021] The described acoustic reproduction of the warning signal, representing the external sound source, as a warning tone inside the vehicle offers the advantage that such a warning tone can be immediately perceived by a driver. Particularly in combination with visual and / or haptic feedback, this results in a particularly effective warning function for the vehicle occupants.

[0022] Another embodiment provides that the at least one sound transducer is configured to transmit directional information about the sound source to the control device together with the electrical signal describing the sound source. This directional information describes the direction in which the sound source is located from a predetermined point inside or on the vehicle. Alternatively or additionally, the directional information describes the distance between the sound source and the predetermined point. To detect the directional information, the at least one sound transducer can, for example, take into account the intensity of the acoustic signal. The lower the intensity of the acoustic signal, the further the external sound source must be from the predetermined point inside the vehicle.An intensity distribution measured over a detection range of at least one sound transducer can also provide information about the direction in which the sound source is located from the predetermined point.

[0023] Preferably, the motor vehicle according to the invention comprises a plurality of sound transducers arranged around the vehicle. Such an arrangement of sound transducers makes it particularly easy to determine the directional information. The transducer that records the highest intensity of the acoustic signal can therefore be identified as the transducer in the direction of the external sound source. In other words, this transducer is looking most directly at the sound source of all the other transducers.

[0024] According to the embodiment described here, the control device is configured to transmit the directional information to the output device. For example, the directional information can be modulated onto the electrical signal. The output device is configured to display the warning message in the vehicle interior, taking the directional information into account. In the case of visual output, this can be done, for example, by displaying arrows pointing in the direction of the sound source. In the case of haptic output, the directional information can be reproduced, for example, via haptic signals distributed spatially within the vehicle interior. In this way, the directional information can be reproduced in the vehicle interior in such a way that a spatial sense of the direction in which the sound source is located is created.

[0025] Preferably, the output device is designed to select, based on directional information, the loudspeaker in the vehicle interior that is closest to the predetermined point in the vehicle interior or on the vehicle in the direction in which the sound source is located from that predetermined point. For example, if the external sound source is located to the left rear of the vehicle, the warning tone can be emitted by a loudspeaker located also at the rear left of the vehicle interior. In particular, a combination of the aforementioned output methods can create a particularly realistic spatial sense of the direction in which the sound source is located within the vehicle interior. This advantageously improves the detection of an approaching sound source.In other words, the direction from which the relevant noise originates can be identified and the corresponding sound output from the same direction via the interior sound system. This also provides the vehicle occupant with intuitive directional information.

[0026] The transducer is designed to continuously receive the acoustic signal describing the sound source, enabling dynamic, real-time adjustment of the corresponding output in the vehicle interior. For example, if the external sound source approaches the vehicle, the acoustic warning tone inside the vehicle can increase in volume. If the external sound source moves away, the warning tone can decrease in volume.

[0027] Another embodiment provides that the control device is configured to forward the electrical signal describing the sound source to the output device only when a relevance criterion is met. This advantageously prevents irrelevant acoustic signals from being transmitted into the vehicle interior. The relevance criterion can be met, for example, when the intensity of the acoustic signal reaches or exceeds a predetermined threshold. In other words, the acoustic signal from the external sound source is preferably only transmitted into the vehicle interior if the sound source is loud enough. The relevance criterion can also describe a dependency on a frequency range of the acoustic signals or the acoustic signal of the external sound source.For example, the described transmission into the vehicle interior can be made dependent on whether the external sound source emits noise from a specific sound spectrum or frequency spectrum. This could, for instance, be the frequency range of a siren. Another example of a fulfilled relevance criterion is the direction from which the acoustic signal reaches the vehicle. For example, only signals originating from the side and / or rear of the vehicle, or approaching the vehicle, can be transmitted.

[0028] According to an advantageous further development, the control device is designed to determine whether the relevance criterion has been met, taking into account sensor data acquired by other sensors of the vehicle. For example, the control device can compare this data with an image simultaneously captured by a vehicle camera. For instance, a situation may arise where the vehicle is honked at. It may be unclear whether the horn signal is actually directed at the vehicle or another vehicle. If the camera recording can verify that, for example, the vehicle following the vehicle emits a flashing headlight signal at the same time as the detected horn signal, it can be verified that the horn signal actually pertains to the vehicle in question. In this case, the relevance criterion would be met, and the signal would be passed through.

[0029] Another embodiment provides that the at least one transducer is designed to be switchable and configured to operate, at least temporarily, in a second switching state, which differs from the first. In the second switching state, the transducer converts an electrical signal into an acoustic signal. In other words, the transducer functions as a loudspeaker in the second switching state. The transducer can therefore be designed to be switchable, meaning that it can be operated alternately in the first and second switching states. To establish the respective switching state, the control device is configured to transmit a switching signal describing the respective switching state to the transducer. The command chain for establishing the desired switching state thus preferably begins at the control device.This is electrically connected to the transducer, with the electrically conductive connection potentially including a switch or switching element which, depending on its switching state, ensures that the transducer operates in either the first or second switching state. The control device can receive the command to transmit the respective switching signal, for example, via manual user input from a vehicle occupant. In other words, it may be possible for the vehicle occupant to trigger a switch between the switching states by manually operating a corresponding button or by using a voice command.

[0030] Preferably, the control device is designed to transmit the switching signal relating to the respective switching state to the sound transducer as a function of the current driving speed of the motor vehicle, in particular automatically.

[0031] According to an advantageous embodiment, the transducer is configured to receive, in the second switching state, an electrical signal describing the current operating state of the motor vehicle, convert it into an acoustic signal describing the current operating state, and emit this acoustic signal into the external environment of the motor vehicle. In other words, the at least one transducer is preferably an external sound loudspeaker of the motor vehicle. It is known to provide external sound loudspeakers, for example, on electric or hybrid-powered motor vehicles, since these emit no or only very quiet engine noise. By emitting acoustic signals corresponding to the missing engine noise, such a motor vehicle can, for example, draw the attention of a pedestrian or cyclist.According to the embodiment described here, such an external sound loudspeaker, designed as a switchable transducer, can be operated as a microphone in addition to its function as an external sound loudspeaker. This offers the advantage that the external sound loudspeakers already present in the vehicle can also be used as microphones with particular efficiency.

[0032] The current operating state of the vehicle, which is reflected in the operation of the external sound speaker, can include, for example, the vehicle's current speed. In other words, the sound emitted by the external sound speaker can be louder the faster the vehicle is currently traveling. Such external sound speakers are generally operated up to a speed of 20 km / h, as at higher speeds the rolling noise of the vehicle's tires or air resistance noise produces a sufficiently loud sound. In other words, the external sound speakers are not used as speakers when the vehicle is traveling faster than 20 km / h. Ideally, the external sound speakers are also not used as speakers when the vehicle is stationary.

[0033] According to an advantageous embodiment, the control device is designed to transmit the switching signal regarding the respective switching state to the transducer, depending on the current speed of the vehicle. Preferably, this transmission occurs automatically. In other words, the control device automatically switches the transducer from the second to the first switching state as soon as the vehicle is not using the transducer as an external sound speaker. If the vehicle has a plurality of such transducers, the control device can also select specific transducers, switching only those selected from the second to the first switching state when they are not being used as external sound speakers. The remaining transducers can continue to be operated as external sound speakers.This advantageously allows both the functionality of the external sound speaker and the functionality of the inventive transmission of acoustic signals from external sound sources into the vehicle interior to be provided simultaneously.

[0034] The invention further relates to a method for operating a motor vehicle with at least one sound transducer. The sound transducer is configured to be operated, at least intermittently, in a first switching state, wherein the sound transducer converts an acoustic signal into an electrical signal in the first switching state. According to one method step, the sound transducer receives as an acoustic signal a signal describing a sound source external to the vehicle in an external environment of the motor vehicle. The sound transducer then converts the received signal into an electrical signal describing the sound source. The electrical signal is transmitted by the sound transducer to a control device of the motor vehicle. According to a further method step, the control device receives the electrical signal describing the sound source from the sound transducer and forwards it to an output device located in the interior of the motor vehicle.The output device receives the electrical signal describing the sound source and outputs it as a warning message representing the sound source in the vehicle interior.

[0035] The invention also includes further developments of the method according to the invention, which have features already described in connection with the further developments of the motor vehicle according to the invention, and vice versa. For this reason, the corresponding further developments of the method according to the invention are not described again here.

[0036] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0037] The invention also includes combinations of the features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0038] For use cases or application situations that may arise during the procedure and are not explicitly described here, it may be provided that, according to the procedure, an error message and / or a request for user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0039] The invention also includes the control device for the motor vehicle. The control device can comprise a data processing device or a processor unit configured to carry out an embodiment of the method according to the invention. For this purpose, the processor unit can comprise at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (Field Programmable Gate Array) and / or at least one DSP (Digital Signal Processor). Furthermore, the processor unit can comprise program code configured to carry out the embodiment of the method according to the invention when executed by the processor unit. The program code can be stored in a data memory of the processor unit. The processor circuitry of the processor unit can, for example, comprise at least one circuit board and / or at least one SoC (System on Chip).

[0040] As a further solution, the invention also includes a computer-readable storage medium comprising program code which, when executed by a processor circuit of a computer or a computer network, causes it to execute an embodiment of the method according to the invention. The storage medium can, for example, be provided at least partially as a non-volatile data storage medium (e.g., as flash memory and / or as an SSD - solid state drive) and / or at least partially as a volatile data storage medium (e.g., as RAM - random access memory). The storage medium can be located within the processor circuit's data storage. Alternatively, the storage medium can also be operated, for example, as an app store server on the internet. The computer or computer network can provide a processor circuit with at least one microprocessor.The program code can be provided as binary code or assembler and / or as source code of a programming language (e.g. C) and / or as a program script (e.g. Python).

[0041] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a schematic representation of a motor vehicle according to an advantageous embodiment of the present invention; Fig. 2 a schematic representation of a method for operating a motor vehicle according to the invention.

[0042] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0043] In the figures, identical reference symbols denote functionally equivalent elements.

[0044] Fig. Figure 1 shows a schematic representation of a motor vehicle 10 with two exemplary sound transducers 12. The sound transducers 12 can be configured as switchable sound transducers 12, whereby in a first switching state they can convert an acoustic signal into an electrical signal and in a second switching state an electrical signal into an acoustic signal. The sound transducers 12 are electrically connected to a control device 14 of the motor vehicle 10. The control device 14, in turn, is electrically connected to several interior loudspeakers or loudspeakers 16, wherein the loudspeakers 16 are designed to emit acoustic signals into a motor vehicle interior. The loudspeakers 16 can be loudspeakers 16 that are integrated into an infotainment or entertainment system of the motor vehicle 10.

[0045] In the Fig. In the example shown, the sound transducers 12 can be in their first switching state. At least the one shown in Fig. The transducer 12, shown on the right, receives an acoustic signal describing a sound source 18 located outside the vehicle 10. The transducer 12 converts this acoustic signal into an electrical signal, which it then transmits to the control device 14 via a communication link designated here as 20. The control device 14 receives the signal and forwards it to an output device (not explicitly shown here), the loudspeakers 16 being part of the output device. The control device 14 thus forwards the signal to the loudspeakers 16. The loudspeakers 16 are configured to receive the signal describing the sound source 18 from the control device 14 and to output it as a warning tone representing the sound source 18 inside the vehicle.

[0046] The 12 sound transducers can be used in the Fig. The transducers 12 shown in Figure 1 can also be operated in the second switching state. In the second switching state, the transducers 12 receive an electrical signal from the control device 14 via a communication link designated here as 22. This signal can, for example, describe the current operating state of the vehicle 10. In the second switching state, the transducers 12 are configured to convert the electrical signal into an acoustic signal and emit it into the external environment of the vehicle 10. In other words, the transducers 12 can be operated as external sound speakers for the vehicle 10 in the second switching state.

[0047] In Fig.Figure 2 shows a schematic representation of a method for operating a motor vehicle 10. The motor vehicle 10 comprises at least one sound transducer 12, which is configured to be operated at least temporarily in a first switching state, wherein the sound transducer 12 converts an acoustic signal into an electrical signal in the first switching state.

[0048] In process step S1, the transducer 12 receives an acoustic signal describing a sound source 18 located outside the vehicle 10. In step S2, the transducer 12 converts the acoustic signal describing the sound source 18 into an electrical signal and transmits this to a control device 14 of the vehicle 10. In step S3, the control device 14 receives the electrical signal describing the sound source 18 from the transducer 12 and forwards it to an output device located in the vehicle interior. Finally, in step S4, the output device receives the electrical signal describing the sound source 18 from the control device 14 and outputs it as a warning message representing the sound source 18 in the vehicle interior.

[0049] Overall, the examples show how the external sound speakers of a motor vehicle can be used to detect and transmit relevant external noises into the interior of a motor vehicle.

Claims

[1] Motor vehicle (10) with at least one sound transducer (12) designed to be operated at least temporarily in a first switching state, wherein the sound transducer (12) in the first switching state converts an acoustic signal into an electrical signal, wherein the sound transducer (12) is configured to receive, in the first switching state, an acoustic signal describing a sound source (18) external to the vehicle in an external environment of the motor vehicle (10), to convert it into an electrical signal describing the sound source (18) and to transmit the electrical signal describing the sound source (18) to a control device (14) of the motor vehicle (10), wherein the control device (14) is configured to receive the electrical signal describing the sound source (18) and to forward it to an output device arranged in a motor vehicle interior, wherein the output device is configured to receive the electrical signal describing the sound source (18) and to output it as a warning message representing the sound source (18) in the motor vehicle interior, wherein the output device has a computing unit configured to convert the electrical signal into the warning message representing the sound source (18), wherein the warning message comprises a rising and falling visual and haptic signal representing the sound source (18), wherein the vehicle-external sound source (18) is an ambulance or a police car with a siren, wherein the output device is configured to reproduce a rising and falling siren as a rising and falling light signal and as a rising and falling haptic signal visually and haptically in the vehicle interior, wherein the haptic signal comprises a vibration of a steering wheel of the vehicle, wherein the sound transducer (12) is designed to continuously receive the acoustic signal describing the sound source (18) for a dynamic live adjustment of the corresponding output in the vehicle interior. [2] Motor vehicle (10) according to claim 1, wherein the output device comprises at least one loudspeaker (16) arranged in the interior of the motor vehicle, wherein the control device (14) is configured to transmit the electrical signal describing the sound source (18) to the loudspeaker (16), wherein the loudspeaker (16) is configured to output the electrical signal describing the sound source (18) as a warning tone representing the sound source (18) in the interior of the motor vehicle. [3] Motor vehicle (10) according to any of the preceding claims, wherein the at least one sound transducer (12) is configured to transmit directional information about the sound source (18) to the control device (14) together with the electrical signal describing the sound source (18), wherein the directional information describes a direction in which the sound source (18) is located from a predetermined point in the vehicle interior and / or wherein the directional information describes a distance that the sound source (18) has to the predetermined point in the vehicle interior, wherein the control device (14) is configured to transmit the direction information to the output device, the output device is designed to output the warning message taking into account the directional information in the vehicle interior. [4] Motor vehicle (10) according to claims 2 or 3, wherein the output device is configured to select, based on the directional information, the loudspeaker (16) in the interior of the motor vehicle for the output of the warning tone which is closest to the direction in which the sound source (18) is located from the predetermined point in the interior of the motor vehicle. [5] Motor vehicle (10) according to one of the preceding claims, wherein the control device (14) is configured to forward the electrical signal describing the sound source (18) to the output device only if a relevance criterion is met. [6] Motor vehicle (10) according to claim 5, wherein the control device (14) is configured to determine whether the relevance criterion has been met, taking into account sensor data acquired by further sensors of the motor vehicle (10). [7] Motor vehicle (10) according to any of the preceding claims, wherein at least one sound transducer (12) is designed to be switchable and is configured to be operated at least temporarily in a second switching state, wherein the sound transducer (12) in the second switching state converts an electrical signal into an acoustic signal, wherein the control device (14) is designed to transmit a switching signal describing the respective switching state to the sound transducer (12) in order to establish the respective switching state. [8] Motor vehicle (10) according to claim 7, wherein the at least one sound transducer (12) is configured to receive, in the second switching state, as an electrical signal, a signal describing a current operating state of the motor vehicle (10), to convert it into an acoustic signal describing the current operating state and to emit the acoustic signal describing the current operating state into the external environment of the motor vehicle (10). [9] Motor vehicle (10) according to one of claims 7 or 8, wherein the control device (14) is configured to transmit the switching signal relating to the respective switching state as a function of a current driving speed of the motor vehicle (10) to the sound transducer (12). [10] Method for operating a motor vehicle (10) according to any one of the preceding claims, wherein the motor vehicle (10) comprises at least one sound transducer (12) which is configured to be operated at least temporarily in a first switching state, wherein the sound transducer (12) converts an acoustic signal into an electrical signal in the first switching state, wherein the sound transducer (12) receives as an acoustic signal a signal describing a sound source (18) external to the vehicle in an external environment of the motor vehicle (10), converts it into an electrical signal describing the sound source (18) and transmits the electrical signal describing the sound source (18) to a control device (14) of the motor vehicle (10), wherein the control device (14) receives the electrical signal describing the sound source (18) and forwards it to an output device arranged in a motor vehicle interior, wherein the output device receives the electrical signal describing the sound source (18) and outputs it as a warning message representing the sound source (18) in the vehicle interior, wherein a computing unit of the output device converts the electrical signal into the warning message representing the sound source (18), wherein the warning message comprises a rising and falling visual and haptic signal representing the sound source (18), wherein the vehicle-external sound source (18) is an ambulance or a police car with a siren, wherein the rising and falling of the siren is reproduced visually and haptically in the vehicle interior as a rising and falling light signal and as a rising and falling haptic signal, wherein the haptic signal comprises a vibration of a steering wheel of the vehicle, wherein the sound transducer (12) continuously receives the acoustic signal describing the sound source (18), so that a dynamic live adjustment of the corresponding output in the vehicle interior takes place.

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