Method and device for adapting an audio output to the user of a vehicle, as well as motor vehicle

Abstract

Method for adapting an audio output to users of a vehicle, wherein the vehicle is designed with separate audio zones for different seating positions, in which - for different users of the vehicle, an individual set of parameters describing the frequency-dependent hearing ability of the respective user is determined (2); and - by means of the respective individual parameter set in the vehicle for multiple users, depending on the seating position, a suitable correction of the audio output signal is made by a frequency response and dynamic range adjustment for different frequency ranges (4).

Description

[0001] The present invention relates to a method for adapting an audio output to the user of a vehicle. The present invention further relates to a device for carrying out the method and a vehicle that is configured to carry out such a method or that includes such a device.

[0002] Audio playback is now standard equipment in motor vehicles. This includes radio and media playback via the vehicle's built-in radio or infotainment systems, which may also be connected to mobile devices such as cell phones. Furthermore, voice output can be provided by driver assistance systems, for example, when a navigation system provides information about the route.

[0003] To ensure the audibility of audio signals while driving, an automatic volume control can be implemented. This system adjusts the volume of the playback device to the ambient noise level. As ambient noise increases, the audio signal's volume level is raised, making it less distracting and allowing the listener to hear and understand the audio signals more clearly. This adjustment applies to all audio signals in the same way.

[0004] A vehicle audio system with voice output, in which the volume is automatically adjusted based on previous volume settings, is disclosed in US 8 050 419 B2. In this system, when voice output begins, the initial volume setting is automatically adjusted if it is detected that the user has repeatedly increased the volume during previous voice outputs.

[0005] German patent DE 10 2014 218 065 B4 discloses a method and a device for adjusting the acoustic parameters of a personalized driver assistance system, in particular a parking aid. This is intended to reduce the risk of warning tones from a driver assistance system no longer being perceived due to hearing loss at high frequencies. For this purpose, the driver is first identified, and in the case of a hard-of-hearing driver, an interior camera is used to check whether the driver is wearing a hearing aid. If it is detected that the hearing aid is missing and the frequencies of the driver assistance system's warning tones are normally above the threshold frequency perceived by the driver, the frequencies are reduced to below this threshold frequency to enable the driver to perceive the warning tones even without a hearing aid.

[0006] In DE 10 2011 076 484 A1, an acoustic signal is processed for playback, and listening scenario information is provided for a simulated listening scenario. The simulated listening scenario influences the perception of the signal and / or defines a signal type. For playback, parameter settings are recorded by the user, reflecting the listener's individual preference in light of the simulated listening scenario. The playback of the signal is then modified according to these playback parameter settings.

[0007] US Patent 2017 / 0048619A1 discloses a method for processing audio output, taking into account the hearing characteristics of a user and the characteristics of an audio device, in particular headphones, connected to an electronic device. The electronic device is configured to capture identification information and characteristics of the audio device, select audio adaptation information, modify an audio signal at least partially based on the audio adaptation information, and transmit the modified audio signal to the audio device.

[0008] German patent application DE 10 2014 210 606 A1 discloses a method for adapting audio signals in a vehicle. A driving-dependent audio signal, to be output by an acoustic output unit of the vehicle, and information regarding the hearing ability of a vehicle occupant are determined. The driving-dependent audio signal is adapted based on the information regarding the occupant's hearing ability and output via the acoustic output unit.

[0009] It is an object of the invention to provide an improved method and an improved device for adapting an audio output to users of a vehicle.

[0010] This problem is solved by a method having the features of claim 1 and by a corresponding device according to claim 7. Preferred embodiments of the invention are the subject of the dependent claims.

[0011] The invention is based, firstly, on the understanding that hearing ability exhibits a complex frequency dependence due to effects such as the sidetone threshold and so-called masking, and that this dependence varies for different users depending on their anatomical conditions, age, and any existing hearing impairment. Building on this, the invention is based on the further understanding that speech intelligibility when using voice output in a vehicle can be optimized by personalized adaptation to the hearing ability of the individual user.

[0012] In the inventive method for adapting audio output to users of a vehicle equipped with separate audio zones for different seating positions, an individual set of parameters describing the frequency-dependent hearing ability of each user is determined for each user of the vehicle. Using the respective individual set of parameters, a suitable correction of the audio output signal is made in the vehicle for several users, depending on their seating position, by adjusting the frequency response and dynamics for different frequency ranges.

[0013] According to the invention, this enables, in particular, a more easily understandable voice output for the respective user. This can increase driving safety, as safety-relevant information, such as warnings about accidents along the route or hazardous objects on the road, can be received more reliably. Messages not related to driving safety can also be understood more clearly, thus increasing user comfort. Likewise, improved audio playback from the other party during telephone calls or when listening to music, audiobooks, etc., is achieved.

[0014] According to one embodiment of the invention, a hearing test is performed for each of the different users, and based on the results of the respective hearing test, an individual set of parameters describing the hearing ability of the respective user is generated.

[0015] Preferably, the hearing test is conducted using the vehicle's built-in speakers. This allows the user's hearing ability to be determined under precisely the same conditions as the subsequent audio output. Since the perception of audio output also depends on the room acoustics of the playback location, these are taken into account when generating the individual parameter set and during any subsequent correction using this set.

[0016] According to one embodiment of the invention, the respective individual parameter set is linked to a user profile of the respective user, with different user profiles being created for different users of the vehicle. This makes it possible to make different corrections to the audio output signal for different users in one vehicle after selecting the respective user profile. Likewise, the same correction can be made for the same user in several vehicles using their personal user profile.

[0017] According to a further embodiment of the invention, one or more parameters describing the vehicle or its environment can additionally be taken into account during the correction. Since the masking effects of human hearing also play a role in the user's hearing ability, whereby the desired sound signals are partially or completely masked by the background noise signals depending on the frequency, even better audibility of the audio output can be achieved in this way.

[0018] Preferably, the parameters include the current speed of the vehicle, currently measured background noise and / or current operating parameters of noise reduction systems in the vehicle.

[0019] Accordingly, a device according to the invention for adapting an audio output to users of a vehicle which is designed with separate audio zones for different seating positions comprises that for different users an individual parameter set describing the frequency-dependent hearing ability of the respective user is determined and a correction filter, using the respective individual parameter set in the vehicle for several users, depending on the seating position, makes a suitable correction of the audio output signal by means of a frequency response and dynamic range adjustment for different frequency ranges.

[0020] According to one embodiment of the invention, correction curves are stored in at least one look-up table, which are used for correcting the audio output signal.

[0021] According to a further embodiment of the invention, signal processing blocks for IIR filters, FIR filters or dynamic processors in different frequency bands are provided.

[0022] The invention also relates to a motor vehicle in which the inventive method or device is used.

[0023] Further features of the present invention will become apparent from the following description and the claims in conjunction with the figures. Fig. Figure 1 schematically shows a flowchart of a method according to the invention for adapting an audio output to the user of a vehicle; and Fig. Figure 2 schematically shows a block diagram of a device according to the invention.

[0024] To better understand the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. It is understood that the invention is not limited to these embodiments and that the described features can also be combined or modified without departing from the scope of protection of the invention as defined in the claims.

[0025] Fig. Figure 1 schematically shows a flowchart of a method according to the invention for adapting an audio output, in particular a speech signal, to the user of a vehicle. According to method step 1, the user first performs a hearing test to determine an audiogram that represents their frequency-dependent hearing sensitivity. This can be done, for example, using a mobile device such as a mobile phone, tablet computer, or laptop computer, on which a computer application for conducting a hearing test, a so-called hearing test app, is installed. The computer application can display a graphical user interface by which the user can, for example, specify whether they are performing the hearing test with headphones or in another way, select the type of headphones, and, if necessary, answer questions about age and gender in order to make suitable default settings for the hearing test.

[0026] Various techniques can be used for hearing tests. For example, different test signals of varying pitch and volume can be played sequentially through headphones connected to a mobile device. The user indicates when they can hear each tone, for instance, by pressing a button on the device used for the hearing test. This also allows for testing how well the test signals can be perceived in the presence of background noise, as this better represents everyday listening situations. In this way, hearing ability can be examined, particularly with regard to the so-called passivity threshold and masking. To test not only audibility but also recognition, short words, individual vowels, or numbers can be played instead of individual tones for the hearing test.For example, by displaying several similar-sounding words, vowels or numbers on a screen and then having the user make a selection, it can be checked when the user recognizes them correctly or no longer correctly.

[0027] Instead of using headphones, the hearing test can also be performed using the vehicle's infotainment system by playing the test signals through the system's speakers. For this purpose, the computer application used to conduct the hearing test can be installed in the vehicle as part of a driver assistance system, allowing the vehicle's controls to be used for user input. Similarly, if the computer application is installed on the user's mobile device, the device can be paired with the vehicle, for example via Bluetooth, to use the infotainment system's speakers for the test signals.Finally, instead of using a computer application installed on the mobile device or the assistance system, a computer application installed on a server can also be accessed via a mobile data connection between the vehicle and the server to perform an online hearing test.

[0028] After completion of the hearing test, information about the user's hearing ability may be displayed on a screen of the mobile device or infotainment system.

[0029] The results of the hearing test are used in step 2 to generate an individual parameter set for the user. This parameter set then enables frequency response and dynamic range adjustment for different frequency ranges of the audio signal during future audio output through digital signal processing, thus optimizing perception and intelligibility for the user.

[0030] If the hearing test in procedure step 1 is performed using headphones, the audiogram for the left and right ear is available separately. To adjust the audio output in the vehicle, it may then be necessary to generate common correction values ​​for the user's frequency-dependent hearing sensitivity from this separate information by "downmixing" the audiograms. The user can then, if necessary, weight whether the left or right audiogram should be given more weight.

[0031] If the hearing test is performed via the vehicle's speakers, it is a "mono measurement" of the user's acoustic perception, as the hearing sensitivity of each ear is not determined separately. If the audio output in the vehicle is then to be via a multi-channel audio playback system, such as a stereo speaker system, the correction values ​​resulting from the "mono measurement" are applied identically to both stereo signal paths of the audio signal to be output. Alternatively, it is also possible to route a mono sum signal of the audio signal through a correction filter. Which of the two corrections is used depends on the specific application.

[0032] It is also possible to import an existing audiogram from an acoustician or ear doctor into the hearing test app, possibly by transferring it from a digital health card.

[0033] In process step 3, the generated parameter set is linked to a user profile. This individual user profile may already be stored on the mobile device or the vehicle's infotainment system and may already contain presets, such as the user's favorite radio stations, and then simply be supplemented with the parameter set. Alternatively, a new user profile can be created if none already exists for that user. Different user profiles can also be created for different users of the vehicle. If the user profile is stored on the mobile device, the user can use it in multiple vehicles. In vehicles with separate audio zones for different seating positions, the appropriate adjustment can be applied for one or more users, depending on their seating position.This allows multiple corrections or adjustments to be made in parallel, enabling the best possible audio / speech playback for the respective user.

[0034] In process step 4, the parameter set is then used to correct the audio output signal by adjusting the frequency response and dynamic range for different frequency ranges of the audio signal. During this audio signal correction, suitable algorithms can also incorporate other parameters relating to the vehicle or its environment. For example, the vehicle's current speed provides a measure of the driving noise, which can be considered as background noise. Similarly, engine noise can be taken into account by evaluating the current engine speed. Furthermore, the current vehicle position, which can be determined from GPS signals, can be used to infer the typical acoustic conditions of the vehicle's surroundings. Likewise, the actual background noise can be measured by a microphone integrated into the vehicle.This can also include measurements of background noise from noise reduction systems, such as the noise reduction technologies ANC, EOC and RNC.

[0035] In step 5 of the process, the corrected audio signal is then played back to the user via the vehicle's infotainment system. The audio signal can be output through the vehicle's built-in speakers. Alternatively, it can be transmitted to headphones or a hearing aid, preferably wirelessly connected to the infotainment system. The user can adjust the audio output volume manually or automatically to a desired level.

[0036] Fig.Figure 2 schematically shows a block diagram of a device according to the invention. Data to be output as speech information, such as navigation instructions from a navigation system, warnings from a driver assistance system, or operating instructions for an infotainment system, are supplied to a speech generation unit 6. The speech generation unit 6 generates a synthetic speech signal for this data, which is fed to the correction filter 7.

[0037] The correction filter 7 adjusts the audio spectrum of the speech signal using a parameter set determined for the user through a prior hearing test. The filter can perform corrections in the time domain, but preferably in the frequency domain. For frequency-domain correction, separate filter channels can be used, each processing sub-ranges of the entire frequency spectrum. Furthermore, the correction filter can receive input from a control unit, such as the vehicle's current speed, engine speed, or information about the current ambient noise level.

[0038] Depending on the user's individual parameter set and any additional parameters, the correction filter can determine correction values ​​for the speech signal using one or more lookup tables and perform the corresponding correction. Different correction curves can be stored in the respective lookup tables for this purpose. Furthermore, signal processing blocks for IIR filters (infinite impulse response filters), FIR filters (finite impulse response filters), and dynamics processors in different frequency bands can be implemented. These can be implemented by digital signal processors or digital hardware such as FPGAs or ASICs. When using IIR filters, only the respective parameter sets need to be changed, while using FIR filters requires a complex convolution logic with the storage of corresponding impulse responses as correction filters.The dynamic processors allow the level in each frequency band to be adjusted. For example, the level can be reduced to a specific value, the dynamic range can be limited or increased, a small level can be lowered, or a larger level can be raised.

[0039] The corrected speech signal is then fed to a power amplifier 8, which amplifies the speech signals for playback via one or more loudspeakers. The amplified signal is then output via one or more loudspeakers 9.

[0040] The invention can be used in any area of ​​automotive engineering. Reference symbol list 1. Conducting the hearing test 2 Determination of individual parameter set 3 Linking parameter set and user profile 4. Correction of audio output signal 5. Corrected audio output signal 6 Speech generation unit 7 Correction filters 8 power amplifiers 9 speakers

Claims

[1] Method for adapting an audio output to users of a vehicle, wherein the vehicle is designed with separate audio zones for different seating positions, wherein - for different users of the vehicle, an individual set of parameters describing the frequency-dependent hearing ability of the respective user is determined (2); and - by means of the respective individual parameter set in the vehicle for multiple users, depending on the seating position, a suitable correction of the audio output signal is made by a frequency response and dynamic range adjustment for different frequency ranges (4). [2] Method according to claim 1, wherein a hearing test is performed for each of the different users (1) and, based on the results of the respective hearing test, the individual parameter set describing the hearing ability of the respective user is generated. [3] Method according to claim 1 or 2, wherein the hearing test is carried out via the loudspeakers (9) installed in the vehicle. [4] Method according to one of the preceding claims, wherein the respective individual parameter set is linked to a user profile of the respective user (3) and different user profiles are created for different users of the vehicle. [5] Method according to any of the preceding claims, wherein in addition to the correction one or more parameters describing the vehicle or vehicle environment are taken into account. [6] Method according to claim 5, wherein the parameters include the current speed of the vehicle, currently measured background noise and / or current operating parameters of noise reduction systems in the vehicle. [7] Device for adapting an audio output to users of a vehicle, wherein the vehicle is designed with separate audio zones for different seating positions, in which an individual parameter set describing the frequency-dependent hearing ability of the respective user is determined for different users and a correction filter (7) uses the respective individual parameter set in the vehicle to make a suitable correction of the audio output signal for several users, depending on the seating position, by means of a frequency response and dynamic range adjustment for different frequency ranges. [8] Device according to claim 7, wherein correction curves are stored in at least one look-up table which are used for the correction of the audio output signal. [9] Device according to claim 7 or 8, wherein signal processing blocks are provided for IIR filters, FIR filters or dynamic processors in different frequency bands. [10] Motor vehicle equipped to perform a method according to any one of claims 1 to 6 or comprising a device according to any one of claims 7 to 9.

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