Method for controlling communication playback between a hands-free device and a user in a motor vehicle, and hands-free device

Abstract

To provide a method for effectively canceling noise of a hands-free device from inside a vehicle to the surroundings of the vehicle, and a hands-free device. The present invention relates to a method for controlling communication playback between a hands-free device (12) and a user (14) of a motor vehicle (10), the method including using a control device (16) electronically connected to the hands-free device (12) to control and / or at least partially modify at least one acoustic signal (20) emitted from at least one speaker (18) electronically connected to the hands-free device (12) for communication playback; The method includes detecting parameters for detecting a vehicle usage context using at least one first detection device (22) electronically connected to the hands-free device (12); detecting a person (24) in a surrounding area (26) of the vehicle (10) using at least one second detection device (30) electronically connected to the hands-free device (12); detecting a position (32) of the person (24) relative to the vehicle (10); and, depending on the detected position (32), at least in part by a control device (16), modifying a volume and / or speech intelligibility rating of an acoustic signal (20) emitted from at least one speaker (18) and directed toward the position (32) where the person (24) is located.

Description

[Technical Field]

[0001] The present invention relates to a method for controlling the playback of a communication between a hands-free device and a user of a motor vehicle according to the preamble of claim 1. Furthermore, the invention relates to such a hands-free device. [Background technology]

[0002] A hands-free device in a motor vehicle allows communication playback or conversation without using a mobile terminal or a mobile phone. In particular, this must prevent accident situations that may occur due to the driver's inattention when holding a mobile phone. In this case, measures are provided to protect communication playback, for example by using more secure connections and by noise cancellation functions, as well as by positioning the respective components of the hands-free device.

[0003] Patent Document 1 below discloses an automotive audio system including an audio detector for detecting ambient noise outside the vehicle and an audio processing module for processing the ambient noise and identifying an event outside the vehicle therefrom, and providing a warning to the occupants in response to the event.

[0004] Patent Document 2 below discloses a notable in-vehicle privacy system. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2015 / 0137998 A1 [Patent Document 2] UK Patent Application Publication No. 2565518 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the problem of insufficient noise cancellation from the interior of the vehicle to the surroundings of the vehicle to prevent eavesdropping by third parties in the immediate surroundings of the vehicle while the hands-free device is in operation remains.

[0007] The object of the present invention is to provide a method and a hands-free device with which noise cancellation of a hands-free device from the interior of a motor vehicle to the surroundings of the motor vehicle is particularly effective. [Means for solving the problem]

[0008] This problem is solved by a method according to the invention with the features of claim 1 and by a hands-free device according to the invention. Advantageous embodiments of the method according to the invention can also be considered as advantageous embodiments of the hands-free device according to the invention, in which case the hands-free device comprises means for carrying out the method steps in particular. Advantageous developments of the invention are explained by the dependent claims, the following description and the figures.

[0009] A first aspect of the invention relates to a method for controlling communication playback between a hands-free device and a user of a motor vehicle, in which a control device electronically connected to the hands-free device controls at least one loudspeaker electronically connected to the hands-free device, in particular multiple loudspeakers electronically connected to the hands-free device, for the communication playback, by modifying a respective acoustic signal (audio signal) emitted by each loudspeaker for the communication playback.

[0010] In order to achieve the object of the invention, and thereby to provide a method by which noise cancellation of a hands-free device from the interior of a motor vehicle to the surroundings of the motor vehicle is particularly effective, it is provided according to the invention to carry out a number of method steps which are described below.

[0011] In a first method step, parameters for detecting a vehicle use context are detected using at least one first detection device electronically connected to the hands-free device. Thus, during a call via the hands-free device in a vehicle, the vehicle use context, i.e., driving on a highway, waiting at a red light, parking in front of an outdoor pool, or an open sliding roof or side window, is detected for this purpose via the detection device installed in the vehicle. For example, the vehicle's speed and geographic location are also detected when answering or making a call. If the vehicle is traveling at high speed in a sparsely populated area, chance bystanders may not be able to eavesdrop on the call because they can only see or hear the vehicle for a short time. On the other hand, if the vehicle is traveling slowly or stationary with the sliding roof open near an outdoor pool or a market, chance bystanders may be able to eavesdrop on the call for a long period of time.

[0012] In a second method step, people in the vicinity of the vehicle, in particular in the immediate vicinity of the vehicle, are detected by at least one second detection device electronically connected to the hands-free device depending on the parameters of the vehicle use context. Thus, in addition to the vehicle use context, a potential eavesdropper context is also detected. This eavesdropper context may depend in particular on the expected density of people in a particular location, and in particular on the time of day, the day of the week, the weather, etc. This eavesdropper context can be detected by the second detection device installed in the vehicle.

[0013] In a third method step, the position of a person relative to the vehicle is detected, so that in addition to the potential eavesdropper context, the second detection device can be used to detect people and their positions in the immediate surroundings of the vehicle.

[0014] In a fourth method step, the control device modifies the volume and / or speech intelligibility rating of the acoustic signals emitted from at least one speaker and directed at least partially toward the person's location, depending on the detected location. For example, a second detection device is used to detect the location of a person standing around the vehicle, and the location data is transmitted to the control device. The control device is configured to at least partially reduce the volume of these acoustic signals by controlling each speaker whose acoustic signals are directed at least partially toward the person's location. This measure provides directional noise reduction depending on the person's location, thereby reducing the acoustic signals so that the communication playback is less likely to be eavesdropped on by people around the vehicle.

[0015] Therefore, the quality and volume of the sound signal generated by the speaker must be modified. A good speech intelligibility system provides a clear, distinct, and easily intelligible sound output. Here, the very sound output is modified depending on the person's position so that the person barely hears, or hears as inaccurately as possible, what the sound output is coming from the speaker. To achieve this, the sound signal directed toward the person is at least partially modified. In particular, this allows certain areas of the vehicle's interior to be particularly strong, while other areas of the interior are particularly weak. Therefore, hands-free devices have spatial adjustment capabilities that can be used to adapt the communication playback to the acoustic conditions in the vehicle interior, thereby improving the sound quality and comfort during calls and during the playback of the communication.

[0016] In an advantageous embodiment of the present invention, the first detector is an optical detector and / or the second detector is an optical detector. Therefore, in particular, the first detector can be configured as an internal camera and the second detector as an external camera, whereby images from the vehicle interior and the surroundings are captured and transmitted to a control device for analysis. The control device, for example, is configured as an electronic computing device and analyzes the images using software or algorithms to detect the respective parameters or positions of people around the vehicle. Depending on the detected data and parameters, the control device can take further measures to reduce noise. For example, an image of a person on the sidewalk to the right of a parked vehicle is recorded by the vehicle's external camera. The image data is evaluated in the vehicle's electronic computing device or control device and assigned to an object class with pixel accuracy, for example, using computer vision (CV) methods. This makes it possible to recognize and locate people in the images.

[0017] In a further advantageous embodiment of the invention, the first detection device is provided as a sensor device and / or the second detection device is provided as a sensor device, for example the two detection devices may be formed as sensor devices with a microphone, an ADAS signal receiver and a motion sensor, which detect the position of the windows and sliding roof, the speed of the vehicle and the presence of people in the vicinity.

[0018] In a further advantageous embodiment of the present invention, a second detection device is used to detect the trajectory of a person's position change around the vehicle. In addition to potential eavesdropper context, people in the immediate vicinity of the vehicle can be detected by the second detection device, for example, formed as a sensor device with the vehicle's external sensor system, using additional components, such as cameras, LiDAR, radar, and ultrasound, arranged for more efficient detection of parameters and positions. Thus, by detecting the trajectory of people and their position changes, the positions of people, particularly those in the immediate vicinity of the vehicle, relative to the vehicle's orientation can be detected at all times. This allows the control device to continuously control the sound reduction in response to the moving people. If the second detection device is an optical detection device, it is possible to determine the movement of people relative to the vehicle, i.e., relative to the orientation of the camera, which is fixed relative to the vehicle's orientation, from a sequence of images / camera images taken in time.

[0019] Likewise, an embodiment of the invention in which the control device is wirelessly connected to a data center has proven advantageous. This allows for the detection of potential eavesdropper contexts in addition to the vehicle usage context, such as data on the expected density of people in a particular location, as well as data on the time of day, the day of the week, the weather, etc. This eavesdropper context can then be transmitted from the central data center to the vehicle via a wireless data communication device. Thus, for example, it can be determined that good weather is due to sunshine and high temperatures, and that the fact that it is a Sunday means that there is a particularly high number of people, and therefore that particularly strong noise reduction is required.

[0020] Also advantageous are embodiments of the invention that use a third detection device to detect additional sound levels and / or additional speech intelligibility ratings around the vehicle. In this case, the third detection device may be configured as an external microphone or include multiple external microphones. The external microphones of the vehicle can detect sounds radiating from the interior to the exterior, and the resulting sound pressure levels and speech intelligibility ratings can be recorded or calculated by a control device or an electronic computing device. For example, speech intelligibility can be measured by performing amplitude modulation of noise in the frequency range of, for example, 125 Hz to 10 kHz using a subliminal STIPA test signal (Speech Transmission Index for Public Address Systems) and inferring or quantifying the loss of speech intelligibility from the loss of variability in the recorded external microphone signal.

[0021] Furthermore, it has proven to be an advantageous embodiment of the present invention that the acoustic signal is at least partially modified by the control device depending on the additional volume and / or the additional speech intelligibility level detected in the vehicle's surroundings. In particular, control (adjustment) of a hands-free device can also be performed. In this case, the control depends on various factors, such as the type of vehicle, the type of hands-free system, and the user's personal settings. Thus, the control device as a volume controller and / or sound quality controller is controlled by the user, for example, via the steering wheel, and a third detection device detects the volume and / or speech intelligibility level of the outside world and transmits at least one signal to the control device, thereby at least partially reducing the volume and / or at least partially modifying the speech intelligibility level depending on the position or trajectory of detected people in the surroundings. In particular, the frequency can also be adjusted by an equalizer so that the sound reaching the surroundings is at least partially reduced. For example, frequency bands can be selectively increased or decreased.

[0022] Similarly, embodiments of the present invention that use a fourth detection device to detect individual users have also proven advantageous. Individual vehicle users can be identified or detected by various methods, such as capturing images from a fourth detection device configured as an internal camera. Further common methods include facial recognition using "computer vision," a personal vehicle key as the fourth detection device, or a personal PIN code, which allows recorded data of a user or front passenger to be clearly assigned to a single person. Thus, physiological and driving-specific characteristic values / data of the vehicle can be detected, processed, and assigned to individual individuals by a fourth detection device installed in the vehicle. For example, possible changes in speech intelligibility can be made depending on the user inside, with different frequencies being changed for younger users than for older users.

[0023] Finally, in a further advantageous embodiment of the invention, the acoustic signals are at least partially controlled by the control device depending on the detected individual user data. Information about the user or driver or front passenger can be used to detect or extend a user profile via a fourth detection device, for example formed as an internal sensor system, and thereby to modify the acoustic signals according to the user, thus preserving privacy. For example, the user's age or sound characteristics can be referenced from the user profile or approximately determined from images from the internal camera, and the settings can be controlled to assist that person.

[0024] A second aspect relates to a hands-free device for a vehicle, comprising an electronically connected control device for controlling communication playback between the hands-free device and a user, the control device being configured to at least partially control multiple speakers electronically connected to the hands-free device and the respective volumes of the acoustic signals emitted from the respective speakers for communication playback. At least one first sensing device electronically connected to the hands-free device can detect parameters for detecting a vehicle use context, and at least one second sensing device electronically connected to the hands-free device can detect a person around the vehicle and their position relative to the vehicle in response to the vehicle use context parameters. The control device can reduce the volume of the acoustic signals emitted from the speakers, at least partially directed toward the person's position, in response to the position. For example, the first sensing device can be configured as an optical sensing device, and / or the second sensing device can be configured as an optical sensing device. Alternatively, the first sensing device can be configured as a sensor device, and / or the second sensing device can be configured as a sensor device. The second sensing device can be used to detect a trajectory from changes in the position of a person around the vehicle. It is also possible to wirelessly connect the control device to the data center, thereby detecting, among other things, ambient ambient data. A third detection device can be used to detect a volume of sound around the vehicle, thereby allowing the control device to control the acoustic signal at least in part in response to the detected volume of sound around the vehicle. A fourth detection device can be used to detect individual users, thereby allowing the control device to control the acoustic signal at least in part in response to the detected individual user data.

[0025] In other words, with the described method and the described vehicle hands-free device, it is possible to prevent eavesdropping on conversations taking place via the vehicle hands-free device from outside, or at least to reduce the intelligibility of speech outside the vehicle, so that it becomes extremely difficult to hear conversations in the immediate surroundings of the vehicle. The subject of the present invention therefore makes it possible to increase the privacy of the driver and passengers, and thereby also the feeling of luxury inside the vehicle by digital means (English: digital luxury).

[0026] Further advantages, features and details of the present invention will become apparent from the following description based on preferred embodiments and drawings. The features and combinations of features mentioned in the above description and the following description of the figures and / or shown only in the figures can be used not only in the respective combinations presented, but also in other combinations or alone without departing from the scope of the present invention. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a first schematic diagram illustrating a first embodiment of a method for controlling communication playback between a hands-free device of a vehicle and a user using a data network; [Figure 2] FIG. 2 is a second schematic diagram illustrating a second embodiment of the method, in which the position or trajectory of a person is detected. [Figure 3] FIG. 3 is a third schematic diagram illustrating a third embodiment of the method, in which a microphone is used. [Figure 4] 1 is a flow chart of a possible sequence of the method. [Figure 5] 4 is a further flow chart of a further possible procedure of the method. DETAILED DESCRIPTION OF THE INVENTION

[0028] In the figures, identical elements and elements with the same function are provided with the same reference numerals.

[0029] 1 is a first schematic diagram illustrating a first embodiment of a method for controlling communication reproduction between a hands-free device 12 and a user 14 in a motor vehicle 10, in which a controller 16 electronically connected to the hands-free device 12 is used to at least partially control and / or modify the volume and / or speech intelligibility rating of each of a number of speakers 18 electronically connected to the hands-free device 12, the respective acoustic signals 20 emitted from each speaker 18 for communication reproduction.

[0030] In a first method step S1, parameters for detecting a vehicle use context are detected using at least one first detection device 22 electronically connected to the hands-free device 12. Thus, during use of the hands-free device 12 in the vehicle 10, the vehicle use context is detected by the first detection device 22 attached to the vehicle 10 and / or by a second detection device 30 disposed in the vehicle 10. Parameters such as an open sliding roof near an outdoor pool, a market, or a forest can also be detected. In a second method step S2, people 24 in the surroundings 26 of the vehicle 10, particularly the immediate surroundings 26, are detected using at least one second detection device 30 electronically connected to the hands-free device 12 in response to the vehicle use context parameters. Thus, in addition to the vehicle use context, a potential eavesdropper context is also detected. This eavesdropper context may depend, in particular, on the density of people 24 expected in a particular location, as well as, in particular, on the time of day, day of the week, weather, etc. In a third method step S3, the position of the people 24 relative to the vehicle 10 is detected. Thus, in addition to the potential eavesdropper context, the second detection device 30 can be used to detect people 24 in the surroundings 26 of the motor vehicle 10 and their positions 32. In a fourth method step S4, the control device 16 modifies the volume and speech intelligibility rating of the acoustic signals 20 emitted from the speakers 18 and directed at least in part toward the positions 32 of the people 24 in response to the positions 32. For example, the second detection device 30 is used to detect the positions 32 of people 24 standing in the surroundings 26 of the motor vehicle 10, and the resulting position data is transmitted to the control device 16. The control device 16 is configured to at least in part reduce the volume and speech intelligibility rating of the acoustic signals 20 by controlling each speaker 18 whose acoustic signals 20 are directed at least in part toward the positions 32. This measure performs directional noise modification and / or noise reduction and / or modification in response to the positions 32 of the people 24, thereby modifying the acoustic signals 20 to make the communication playback less susceptible to eavesdropping by people 24 in the surroundings 26 of the motor vehicle 10.

[0031] 1 in particular shows a motor vehicle 10 in which a first detector 22 is provided as an optical detector and / or a second detector 30 is provided as an optical detector, whereby a user / driver 14 is detected from camera images using the first detector 22 configured as an interior camera. Furthermore, the surroundings 26 are also detected using the second detector 30 configured as an exterior camera. The images are transmitted to a control device 16 for evaluation, which may be configured as an electronic computing device or be electronically connected to or include such a device. Thus, the control device 16 detects vehicle use contexts and potential eavesdropper contexts, as well as persons 24 in the immediate surroundings 26 and their positions 32 relative to the vehicle. Furthermore, the control device 16 obtains information from an internal microphone 22a and an external microphone 30a, thereby enabling possible noise reduction and / or classification control, which will be discussed in more detail in other figures.

[0032] In this case, the control device 16 is wirelessly connected to a data center 34. This allows for the identification of a potential eavesdropper context in addition to the vehicle usage context, for example obtaining data on the expected density of people 24 at a particular location, as well as data on the time of day, day of the week, weather, etc. This eavesdropper context can then be transmitted from the central data center 34 to the vehicle 10 via a wireless data communication device 33.

[0033] 2 is a second schematic diagram illustrating a second embodiment of the method, in which the position or trajectory of the person 24 is detected. In this case, the position of the person 24 or the trajectory of the person's 24 position change in the surroundings 26 of the motor vehicle 10 is detected using a second detection device 30, particularly using additional components arranged to more efficiently detect parameters and positions 32, such as a camera, LiDAR, radar, or ultrasound. Thus, by detecting the person 24 and the position or the trajectory of the position change, the position 32 of the person, particularly in the immediate surroundings 26 of the motor vehicle 10, relative to the vehicle's orientation can be detected at any time. This allows the control device 16 to continuously control the sound modification depending on whether the person 24 is stationary or moving. Therefore, an optical detection device as the second detection device 30 can determine the movement of the person 24 relative to the motor vehicle 10, i.e., the movement of the person 24 relative to the orientation of the camera, which is fixed relative to the vehicle's orientation, from a sequence of images / camera images taken in time. In this case shown in FIG. 2, the driver's side speaker 18a is controlled at a louder volume than a further speaker 18b near the person 24, in this case on the passenger side and in the central part of the vehicle 10.

[0034] FIG. 3 is a third schematic diagram illustrating a third embodiment of the method, in which a microphone is used. In particular, the first detection device 22 and / or the second detection device 30 are provided as respective sensor devices, which may, for example, have their own microphones. Thus, in particular, the control device 16 receives information from the internal microphone 22a and the external microphone 30a, thereby enabling possible control of noise reduction. That is, the vehicle 10 is shown in which the speaker 18 plays a voice message or a call, while an acoustic signal 20 is recorded by the external microphone 30a outside the vehicle and transmitted to the control device 16 for evaluation. This also allows for a control loop. If the recorded acoustic signal A exceeds a predetermined value, the control device 16 can perform appropriate noise reduction.

[0035] In particular, voice messages or conversations played through the interior speaker 18 are recorded and analyzed by the control device 16, or the voice intelligibility is quantified. For example, the grade of an automated transcript can be quantified at the time of creation, e.g., by statistics regarding the probability that each individual word was clearly recognized. This results in a quantified voice intelligibility value Q1 within the vehicle. At the same time, a voice intelligibility value Q2 outside the vehicle is calculated using the external microphone 30a. The values ​​of Q1 and Q2, or a value calculated therefrom, such as the ratio of Q1 to Q2, are transmitted to the control device 16, which then modifies the speaker control accordingly. That is, the generated audio or sound signal A is modified so that the conversation inside the vehicle 10 is maximally recognized and minimally recognized in the area outside the vehicle, i.e., the surroundings 26. For example, the Q1 / Q2 quotient can be maximized for this purpose.

[0036] FIG. 4 shows a flowchart of a possible sequence of steps of the method, in which, after a start 36, a first query 38 is made to inquire whether a dialogue should be played through the speaker 18 of the vehicle 10. If the first query 38 is negative (N), the method is stopped by a stop command 40 and a new start 36 is prepared via a first loop 42. If the first query 38 is positive (J), three exemplary commands 46, 48, and 50 are executed in a first control device 44, which may be configured as an electronic computing device. Using the first command 46, parameters are detected according to the vehicle usage context obtained from data detected by the first detection device 22, which may be configured as a sensor device. Using the second command 48, a potential eavesdropper context is detected, in which ambient parameters, such as weather data, are detected by the second detection device 30, which may be configured as an external sensor. Similarly, information can be received from a data center 34, which is wirelessly connected to the first control device 44, and this information can be taken into account for noise reduction and / or noise modification. Next, the person 24 is detected using a third command 50, in which the second detection device 30, configured as, for example, an external sensor, detects the position 32 of the person 24 in the surroundings 26 of the vehicle 10. By combining the data and / or information and / or parameters, the control device 44, configured as an electronic computing device, transmits a fourth command 52 to the second control device 54, thereby performing vehicle-use context-dependent control 56 of the speaker 18. This action performs directional noise reduction and / or scaling depending on the position 32 of the person 24, thereby reducing the acoustic signal 20 so that the communication playback is less likely to be eavesdropped on by people 24 in the surroundings 26 of the vehicle 10. The method then begins anew from start 36 via a second loop 58.

[0037] 5 shows a flowchart of a further possible step of the method. Here, the first control device 44, configured as an electronic computing device, is provided with a further command 60, by which a quantification of the audio content recognition is calculated, as explained in FIG. 3, for which data is detected by the internal and external microphones 22a, 30a of the respective detection devices 22, 30. Therefore, a further control 62 of the speaker 18 is performed by the second control device 54 in order to reduce the quality of the audio signal 20 to the external surroundings 26, as well as the volume and intensity. However, the quality of the audio signal 20 is maintained or improved within the vehicle 10. A further query 64 then queries whether the conversation, and thus the communication playback, should be terminated.

[0038] If "no" N, i.e. if the further inquiry 64 is denied, the first control device 44, configured as an electronic computing device, is again instructed via a loop 66 to sense data and / or information and / or parameters, thereby achieving a new noise reduction in the surroundings 26, which can be repeated at defined time intervals. If "yes" J, i.e. if the further inquiry 64 is confirmed, the method is started again anew from the start 36 via a second loop 58.

[0039] In particular, to carry out the method, a hands-free device 12 of a vehicle 10 is provided that includes an electronically connected control unit 16 for controlling communication playback between the hands-free device 12 and a user 14, the control unit being configured to at least partially control a number of speakers 18 electronically connected to the hands-free device 12 and the respective volume of an acoustic signal 20 emitted from each speaker 18 for communication playback. In this case, a parameter for detecting a vehicle use context can be detected using at least a first detection unit 22 electronically connected to the hands-free device 12, and a person 24 in a surrounding 26 of the vehicle 10 and a position 32 of the person 24 relative to the vehicle 10 can be detected using at least a second detection unit 30 electronically connected to the hands-free device 12 and in response to the vehicle use context parameter. Using the control unit 16 and in response to the position 32, the volume of the acoustic signal 20 emitted from the speaker 18 and directed at least in part toward the position 32 of the person 24 can also be reduced, thereby achieving noise reduction in the surroundings 26.

[0040] In other words, Figures 1-5 illustrate three particular technical implementations for preventing or at least reducing speech intelligibility outside the vehicle 10, which make eavesdropping on the conversations of the user 14 extremely difficult, and which can be implemented individually or in combination.

[0041] In this case, in a first implementation, calls made via the hands-free device 12 can be played back in a context-dependent manner using the sound system installed in the car 10, without significantly reducing the quality of the audio playback, thereby improving the privacy of the user 14. To this end, the speaker 18 is controlled in a context-dependent manner during audio playback, as shown in the flowcharts of Figures 4 and 5.

[0042] For example, if the person 24 is on the right side of the vehicle 10, the left speaker 18 can take over playback. As the person 24 moves from the rear right to the front left, the control of the speaker 18 can be adapted to the person's trajectory through the vehicle 10, gradually moving from the front left to the rear right. This effect can be enhanced by using a special 3D audio playback format. Furthermore, if the person 24 is standing directly to the side of the vehicle 10, the volume of the sound signal 20 or audio signal and the resulting over-radiation can be temporarily reduced.

[0043] In a second implementation, the frequency-dependent sound insulation properties of the vehicle 10 can be exploited by "pitch-shifting" (evenly changing all frequencies) or "pitch correction" (various frequency-dependent changes) of the sound signal 20 or audio signal, or alternatively or additionally by using an equalizer (a combination of high-pass and low-pass filters) to filter the sound signal 20 or audio signal, which may generally vary depending on the type and equipment characteristics of the vehicle, thereby reducing the level of sound signals in the surroundings 26 of the vehicle 10.

[0044] In particular, boosting the low frequencies of the sound signal 20 or audio signal results in two competing, counteracting effects. On the one hand, because high frequencies are generally attenuated more strongly by the interior space of the vehicle 10 than low frequencies, boosting these low frequencies equally can be used to achieve a relative increase in sound insulation. On the other hand, however, depending on the sonic characteristics of the sound signal 20 or audio signal, low resonant frequencies may arise that are often barely audible but that become perceived much louder when boosted. Therefore, boosting low resonant frequencies may be considered to cause a particularly undesirable increase in perceived speech intelligibility outside the vehicle 10.

[0045] Thus, boosting the low frequencies of the acoustic signal 20 or audio signal may advantageously improve the sound insulation of the vehicle 10 without significantly reducing perceived speech intelligibility for a young user 14, provided that the low resonant frequencies of the acoustic signal 20 or audio signal are not present in the sound signature of interest. Furthermore, it may be recognized from a user profile of hearing aid wear or based on audiometric measurements performed in the vehicle 10 that boosting the low frequencies is only possible in certain frequency ranges without excessively reducing speech intelligibility for the user.

[0046] In this case, special codecs that can optionally modify pitch and speaking style can compensate for changes and / or alienation of sound characteristics (e.g. dialect, accent, etc.) to preserve or additionally harmonize the original sound characteristics in order to improve speech intelligibility.

[0047] Alternatively, if only the low frequencies of the sound signal 20 or audio signal are reduced, speech intelligibility will be reduced only slightly inside the vehicle 10, as the high frequency audio signal components will be well perceptible, while these high frequency sound or audio signal components will be attenuated in the immediate surroundings 26 of the vehicle 10 due to the sound insulation of the vehicle 10.

[0048] The "pitch shift" or "pitch correction" control strategy accordingly depends on the frequency-dependent sound insulation properties of the vehicle 10, which vary with respect to the acoustic system in the vehicle's interior space and with respect to the measurement location relative to the vehicle 10, and on the sound characteristics of the reproduced speech signal. The frequency-dependent and direction-dependent sound insulation properties can be acoustically measured during development of the vehicle 10, and the sound characteristics can be determined from the speech signal in real time by digital audio signal processing.

[0049] In a third implementation, by using an external microphone 30a attached to the motor vehicle 10, the sound signal 20 or audio signal can be modified so that the sound signal 20 or audio signal, in particular speech, is perceived with maximum speech intelligibility in the interior space of the motor vehicle and with reduced speech intelligibility in the surroundings 26 of the motor vehicle 10. To this end, subliminal STIPA test signals or natural language processing (NLP) methods can be used to automatically convert, for example, the speech content into text.

[0050] If no test signal is used, the difference in the general grade of speech intelligibility dG between the interior space of the motor vehicle 10 and the surroundings 26 can be calculated by measuring / calculating / quantifying the respective grades of speech intelligibility GI of the interior space and speech intelligibility GA of the exterior space and in particular by calculating the ratio of both values, in particular the quotient of both values ​​dG=GA / GI.

[0051] If the same method for determining the speech intelligibility grade is applied based on the sound signals 20 or audio signals played in the motor vehicle 10 and the sound signals 20 or audio signals recorded in the surroundings 26 of the vehicle 10 or from audio information recorded simultaneously from the interior and exterior microphones 22a, 30a, the respective grades of speech intelligibility can be calculated / quantified and compared.

[0052] For example, a speech intelligibility rating can be calculated from an automatic transcription of the conversation using NLP methods, i.e., again, speech reproduction in the automobile 10 can be improved so that the ambient transcription is maximally poor and the in-car transcription is maximally good, or a weighting between the two extremes is achieved. For example, speech intelligibility GI in the interior space can be weighted more strongly than poor intelligibility GA in the ambient (exterior) space, e.g., dG=GA / GI^alpha.

[0053] The grade of the automatic transcript can be quantified, for example, by generating statistics on the probability that each individual word is clearly recognized. This results in a quantified speech intelligibility value GI inside the vehicle 10. Simultaneously, the speech intelligibility GA outside the vehicle is calculated using the external microphone 30a. The GI and GA values, or a value calculated therefrom, such as the GI to GA ratio, are transmitted to the control device 16. The control device 16 then modifies the speaker control, i.e., the generated sound signal 20 or audio signal, so that the speech inside the vehicle 10 is maximally intelligible and minimally intelligible in the surroundings 26 of the vehicle 10. For example, this can be achieved by minimizing the GA / GI quotient using optimization methods known from the prior art, as shown in FIG. 3.

[0054] The vehicle 10 may generally be any vehicle on land, water or in the air. Thus, the vehicle 10 may be a (road) motor vehicle 10 such as a car, truck or bus, or it may be an airplane, seaplane, emergency vehicle 10, construction equipment, agricultural vehicle or military vehicle 10. In particular, it may also be a rail vehicle, for example a train, a suspended railway, a magnetic levitation railway or a capsule that glides on an air cushion in a nearly vacuum tube or is suspended by magnetic forces.

[0055] User 14 may be anyone within vehicle 10, such as the driver, a passenger in the front seat, or any other person in a vehicle provided for transporting people.

[0056] Furthermore, the automatic enhancement of the acoustic signal 20 or audio signal described above may additionally depend on the vehicle usage context and the eavesdropper context, as well as the person 24 recognized in the surroundings 26 of the vehicle 10. To that end, as shown in the flowchart of Figure 5, microphones at different locations outside the vehicle 10 are used, thereby reducing the recognition grade of the speech content by modifying the audio signal for the external microphone 30a closest to the person 24.

[0057] Furthermore, a relatively expensive-looking luxury car stopped at a red light, with the driver of the relatively expensive-looking luxury car discussing business, may contain particularly sensitive or confidential information. The current vehicle usage context (a stopped vehicle 10) and the potential eavesdropper context (a densely populated urban area) may detect a growing need to modify the communication playback using an acoustic device installed within the vehicle 10 to protect the privacy of the user 14 as much as possible. To achieve this, first, the low frequencies of the acoustic signal 20 or audio signal are reduced. If the user 14 of the vehicle 10 is recognized as relatively young from a stored user profile and / or from interior camera images evaluated using computer vision techniques, speech intelligibility within the vehicle 10 may be reduced only slightly or not at all, since the user 14 will still be able to perceive the high-frequency audio signal components well.

[0058] Furthermore, a comparison of the interior and exterior speech intelligibility, based on the interior and exterior microphone recordings and the quantification of the speech intelligibility grade, optimizes the reproduction characteristics of the audio signal, so that the sound signal 20 or audio signal, in particular the speech, is perceived with maximum speech intelligibility inside the vehicle cabin and with reduced speech intelligibility around the vehicle 10. The optimization of the reproduction parameters may depend, for example, on the sound characteristics of the user 14 and other people participating in the call. When a person 24 moves next to the vehicle 10, this is recognized by the vehicle's sensors, and the position of the vehicle 10 and the trajectory relative to the vehicle 10 are determined. Based on this information, the interior speaker 18 can be controlled to further reduce the radiation of the sound signal 20 in the direction of the person 24.

[0059] In other words, the present invention describes context-sensitive control of communication playback in a vehicle to preserve privacy.

Claims

1. 1. A method for controlling a communication playback between a hands-free device (12) and a user (14) of a motor vehicle (10), wherein at least one speaker (18) electronically connected to the hands-free device (12) is controlled and / or at least partially modifies at least one acoustic signal (20) emitted from the at least one speaker (18) using a control device (16) electronically connected to the hands-free device (12), the method comprising: - sensing parameters for detecting a vehicle usage context using at least one first sensing device (22) electronically connected to said hands-free device (12); - detecting people (24) in the vicinity (26) of the motor vehicle (10) using at least one second detection device (30) electronically connected to the hands-free device (12); - the position (32) of said person (24) relative to said vehicle (10) is detected; In a method comprising: During a call using the hands-free device (12), the person (24) in the surroundings (26) of the vehicle (10) is detected according to the parameters of the vehicle usage context, and according to the position (32) of the detected person (24), the volume and / or speech intelligibility rating of the acoustic signal (20) emitted from at least one speaker (18) and directed at least in part to the position (32) of the person (24) is changed by the control device (16). A method characterized by:

2. The first detector (22) is an optical detector, and / or the second detector (30) is an optical detector.

2. The method according to claim 1, characterized in that

3. The first detection device (22) is a sensor device, and / or the second detection device (30) is a sensor device.

3. The method according to claim 1 or claim 2, characterized in that

4. The second detection device (30) is used to detect a trajectory from changes in the position of a person (24) in the surroundings (26) of the vehicle (10). The method according to any one of claims 1 to 3, characterized in that

5. The control device (16) is wirelessly connected to a data center (34). The method according to any one of claims 1 to 4, characterized in that

6. A third detector (36) is used to detect a further volume and / or a further speech intelligibility rating in the surroundings (26) of the vehicle (10). The method according to any one of claims 1 to 5, characterized in that

7. The acoustic signal (20) is at least partially modified by the control device (16) in response to the additional volume of sound detected in the surroundings (26) of the vehicle (10) and / or the additional speech intelligibility level detected.

7. The method according to claim 6, characterized in that

8. A fourth detection device (38) is used to detect individual users (14). The method according to any one of claims 1 to 7, characterized in that

9. The acoustic signal (20) is controlled at least in part using the control device (16) in response to sensed data about the individual user (14).

9. The method according to claim 8, characterized in that

10. 1. A hands-free device (12) comprising: a control device (14) configured to at least partially control a number of speakers (18) electronically connected to the hands-free device (12) and respective volumes of acoustic signals (20) emitted from each of the speakers (18) for communication playback between the hands-free device (12) and a user (14), the control device (14) being electronically connected to the hands-free device (12) for controlling the communication playback; at least one first detection device (22) electronically connected to the hands-free device (12) capable of detecting a parameter for detecting a vehicle use context; and at least one second detection device (30) electronically connected to the hands-free device (22) capable of detecting a person (24) in a surrounding (26) of the motor vehicle (10) and a position (32) of the person (24) relative to the motor vehicle (10), During a call using the hands-free device (12), the person (24) in the surroundings (26) of the motor vehicle (10) can be detected using the second detection device (30) and depending on the parameters of the vehicle use context, and depending on the position (32) of the person (24), the volume of the acoustic signal emitted from the speaker (18) and directed at least in part to the position (32) of the person (24) can be reduced. A hands-free device (12) characterized in that:

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