Hearing device

Abstract

Described herein is a hearing device (1) having a device base body (2) which is worn on the body, in particular the head, of a user; a CW radar unit (10) which is arranged in or on the device base body (2) and is designed to transmit an unmodulated CW radar signal and to receive a corresponding reflected radar signal; and a control unit (6), which is designed to detect a signal part characterizing the micro-Doppler effect from a radar reception signal, which is output by the CW radar unit (10) as a function of the received reflected radar signal, and to derive therefrom the distance of the device base body (2) to an object (20) located in the environment of the user.

Description

Technical Field

[0001] This invention relates to a hearing device, such as a hearing aid. Background Technology

[0002] Hearing devices are typically used to output sound signals to the wearer's ear. This output is achieved through an output transducer, usually transmitted acoustically as airborne sound waves via a speaker (also called a "hearing tube" or "receiver"). Such hearing aids are commonly referred to as hearing aids (or simply hearing aids). For this purpose, hearing aids typically include an acoustic input transducer (especially a microphone) and a signal processor designed to process the input signal (also called the microphone signal) generated from ambient sound by the input transducer using at least one signal processing algorithm typically specific to the user, thereby at least partially compensating for the hearing loss of the hearing aid wearer. Especially in the case of hearing aids, in addition to a speaker, the output transducer can also be a so-called bone conduction earpiece or a cochlear implant, which is used to mechanically or electrically couple sound signals to the wearer's auditory system. Furthermore, some hearing aids can protect or improve the hearing of users with normal hearing, such as improving speech comprehension in complex auditory environments. Such devices are also called "personal sound amplification products" (PSAPs). Hearing devices also include other devices such as so-called tinnitus maskers, headset receivers, and headphones.

[0003] Typical structures for hearing devices, especially hearing aids, are behind-the-ear (BTE) and in-the-ear (IdO or ITE) hearing devices. These names refer to their intended wearing position. BTE devices have a (main) shell worn behind the ear. This type can be distinguished as either having a speaker located within the shell, meaning sound is typically transmitted to the ear through a sound tube worn in the ear canal, or having an external speaker placed in the ear canal. In-the-ear (ITE) hearing devices, however, have a shell worn inside the ear or even entirely within the ear canal.

[0004] The signal processor in most hearing devices (using at least one signal processing algorithm) is also configured to recognize different auditory conditions and adjust signal processing accordingly. To this end, some hearing devices store auditory programs (usually implemented through a specific set of parameters for the corresponding signal processing algorithm), which are then "activated." Common auditory programs include music, conversations in quiet environments, and conversations with background noise. Some auditory programs also activate or deactivate different filters and alter their effect on the received signal. Understanding the user's environment is beneficial for such auditory programs, but also for obtaining better filtering settings, such as for speech recognition or improved speech reproduction. To locate sound sources (e.g., televisions, audio playback devices), multiple microphones can be used to generate and utilize directionality. When using two hearing devices (one for each ear), the distance between the two devices can also be used for better localization. However, non-acoustically active objects cannot be located, or can only be located through detectable sound reflections. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to enable the localization of non-acoustically active objects through hearing devices.

[0006] The technical problem described herein is solved by a hearing device. The advantages of this invention, and some of its inventive embodiments and improvements, are revealed in the following description.

[0007] The hearing device according to the invention has a device base that can be worn on a user's body, particularly the head. The hearing device is particularly a "behind-the-ear" (BTE) hearing aid, having a built-in or external ("in-the-ear receiver RIC" or "external receiver unit ERU") speaker. The hearing device also has a CW radar unit (continuous wave radar) arranged within or on the device base and configured to transmit unmodulated CW radar signals and receive corresponding reflected radar signals. Furthermore, the hearing device has a controller configured to detect signal portions characterizing the micro-Doppler effect from the received radar signals and thereby determine the distance from the device base to objects, particularly fixed in position, in the user's surrounding environment, the received radar signals being provided by the CW radar unit based on the received reflected radar signals.

[0008] The radar unit is preferably a "standard radar chipset," which integrates transmitting and receiving antennas, a signal generator, and other necessary components. This has an economic advantage because commercially available radar units can be used.

[0009] This invention is based on the consideration that "classical" radar ranging methods typically use pulse and / or frequency-modulated radar signals. However, these methods cannot be used with the CW radar unit used in this invention and require relatively high computational power and energy consumption. CW radar can be used for speed or motion detection, for example, by utilizing the Doppler effect. Although objects passing by the user (e.g., passing vehicles, pedestrians, cyclists, etc.) may have a brief effect on the user's hearing, this effect is negligible, especially for signal processing adaptation, due to its relatively short duration. However, this invention is still based on the understanding that motion detection can be used for ranging. But here, it does not detect the motion of the object, but only the change in the relative distance of the object to the moving user, because the starting point of this invention is that people usually move at least slightly. Therefore, it is almost impossible for a user of a hearing device to keep their head completely still. Even a slight movement is sufficient to detect the so-called micro-Doppler effect in the reflected and received radar signals.

[0010] In this context and the following, the "micro-Doppler effect" should be understood in particular as an effect similar to the "known" Doppler effect but significantly weaker. Compared to the overall motion of an object typically detected by the Doppler effect, such as a moving airplane, pedestrian, or moving car, the micro-Doppler effect is weaker and usually involves only localized motion of the object (e.g., airplane propellers, helicopter rotors, body vibrations, pedestrian arm swings). This typically produces sidebands relative to the Doppler frequency shift caused by the overall motion of the object. Therefore, the "characteristic" nature of this micro-Doppler effect refers to certain signal portions that indicate such an effect in terms of amplitude and / or frequency. It is known that when the human body moves, not only does the whole body move, but small movements always occur in its various parts. For example, the human head constantly undergoes at least small movements. Hearing devices worn on the head also experience these small movements. The micro-Doppler effect is described in “Micro-Doppler Effect in Radar: Phenomena, Models and Simulations” by VC Chen, F. Li, S.-S. Ho and H. Wechsler, published in IEEE Transactions on Aerospace and Electronic Systems, Vol. 42, No. 1, pp. 2-21, January 2006, doi: 10.1109 / TAES.2006.1603402.

[0011] As mentioned above, the micro-Doppler effect caused by minute movements can be detected relatively easily using a CW radar unit. While the equivalent value filter typically present in the baseband of such CW radar units filters out the equivalent value generated by the mixture of CW radar and reflected radar signals in the baseband, this is only true if the CW radar unit and the target remain stationary. However, once the micro-Doppler effect occurs—that is, if the device substrate moves slightly relative to the user's head, causing a slight movement in the CW radar unit—this equivalent value will be detected (i.e., no longer filtered out by the filter).

[0012] Preferably, this equivalent value is typically used as a measure of the signal strength of the received reflected radar signal.

[0013] According to a suitable implementation, the controller is configured to decompose the radar received signal, at least the portion of the signal that is characterized for the micro-Doppler effect, into frequency components, particularly by means of a fast Fourier transform.

[0014] According to a preferred embodiment, the controller is configured to determine the digital FFT value, and in particular its equivalent value, of the representative signal portion in order to arrive at the distance. Preferably, the controller is configured, as described above, to treat the digital FFT value with respect to the equivalent value as a measure of signal strength. This method is based in principle on the understanding that the digital FFT value increases as the distance to an object, such as a room wall, increases. Therefore, this information can be used to determine the distance to the object.

[0015] Preferably, the controller is configured to compare the FFT value with a plurality of stored FFT comparison values, each associated with a distance value, in order to derive the distance. The plurality of FFT comparison values ​​are preferably stored in a table (“lookup table” / “LUT”), which is in turn stored in the controller, more specifically, in memory associated with the controller. This is a computationally inefficient method.

[0016] Suitablely, the controller is also configured to, in order to derive the distance, bring the (digital) FFT value of the representative signal portion close to the frequency range of 0 Hz (i.e., 0 + / - 20 Hz) (that is, to determine the digital FFT value of the equivalent value at or near 0 Hz). This is based on the consideration that, in this example, the "target object" is preferably stationary (especially the walls of the user's room, etc.) and no motion should be detected.

[0017] According to a particularly suitable embodiment, the hearing device also includes an inertial measurement unit (IMU) disposed within or on the device substrate. The hearing device (“IMU”) is configured and designed to determine at least a change in the orientation of the device substrate in space. The IMU may be, for example, composed of or contain a triaxial accelerometer or other gyroscope sensor. The controller is preferably configured in this case to, when the IMU determines a change in the orientation of the device substrate, subsequently determine the distance from the device substrate to an object, at least subsequently, using the CW radar unit. The controller is particularly designed to “verify” by the IMU whether the device substrate (and therefore likely the user) is moving and whether it is within a range of movement, such as a small movement of only 0.5 to 10 cm (or at most 5 cm) or a larger movement (e.g., walking in a room, rotating the entire body, etc.). This allows for the differentiation of the micro-Doppler effect in the received (reflected) radar signal caused by user movement from the micro-Doppler effect caused by object movement (e.g., the movement of a door, window sash, or plant leaf). To determine distance, the micro-Doppler effect caused by the user's own movement is useful. Optionally, the controller is also configured to determine whether the range of motion detected by the inertial measurement unit matches the "intensity" of the micro-Doppler effect.

[0018] According to a suitable improvement, the controller is further configured to create an environmental map based on the distance and spatial angle information determined by the inertial measurement unit (IMU) from the user's perspective. This environmental map includes the distances between the hearing device and objects in the user's surrounding environment, particularly walls and / or other objects in the space where the user is located. This method is based on the consideration that the device body is always worn on the user's head in approximately the same position, and therefore, any changes in positioning detected by the IMU are characteristic of head rotation and thus also changes in the direction of vision. The IMU is arranged or mounted within or on the device body such that the 0° direction of the IMU at least approximately corresponds to the user's neutral line of sight (preferably the sagittal direction). If the user, or at least their head, rotates, a map can be created by progressively "scanning" the room where the user is located using a CW radar unit.

[0019] Knowing the distances to objects within a room, especially to the room's walls, is highly beneficial for signal processing. This is because the echo of one's own or others' voices against the walls (also known as "reverberation") can cause unpleasant sound effects, particularly reducing speech perception. Knowing the distances helps reduce such effects, for example, by appropriately setting filters. The controller is preferably also configured to take the distances to the walls into account in order to adjust parameters in signal processing, particularly by adjusting filter parameters accordingly. Here, for example, at least the basic settings of the corresponding filters can be considered. For reverberation filters, settings are known to be suitable for small or large rooms, rooms filled with objects, etc. Based on the various distances, at least a rough three-dimensional map of the user's room can be created. Information about the presence of other people or numerous pieces of furniture (e.g., the direction of uneven wall spacing along the horizontal and vertical directions) can be collected and taken into account.

[0020] According to another suitable embodiment, the controller is configured to average the digital FFT values ​​over a preset time period, particularly 5 to 40 seconds, preferably 15 to 30 seconds, in order to determine the distance. This can improve the accuracy of distance measurement, and in particular reduce short-term effects on the measurement.

[0021] Especially when the CW radar unit used lacks an equivalent value filter in the baseband, according to an advantageous implementation, the controller is configured to use a Kalman filter on the radar received signal to determine the range. Because there is no such equivalent value filter, the equivalent value can be measured even without the micro-Doppler effect. Therefore, in this case, multiple equivalent values ​​can be measured (especially continuously in time). These equivalent values ​​can be used to determine the range, with particularly advantageous accuracy improved by the Kalman filter. The application of the Kalman filter is known in this principle, especially in the field of radar measurement.

[0022] According to a suitable implementation, the controller is configured to obtain motion information about the user's body parts, particularly the user's hands, based on the radar received signal, especially the frequency representation of the radar received signal, and to identify input commands for changing the signal processing parameters of the hearing device based on this motion information. The controller is particularly configured to identify and evaluate such body movements (at least within the detection range of the CW radar unit) using the micro-Doppler effect, particularly in the 0Hz frequency deviation range. Detecting the movement of various body parts via the micro-Doppler effect is known herein (see, for example: Geisheimer, JL, Greneker, E. and Marshall, WS: High-Resolution Doppler Model of Human Gait, Proceedings of the SPIE Conference on Radar Technology, 2002).

[0023] In this context and the following, the conjunction “and / or” should be understood as meaning that the features connected by the conjunction can appear together or as alternatives to each other. Attached Figure Description

[0024] The embodiments of the present invention are further described below with reference to the accompanying drawings. In the drawings:

[0025] Figure 1 A schematic diagram of a hearing device with a CW radar unit is shown.

[0026] Figure 2 The diagram shows a graph illustrating the frequency domain representation of two reflected radar signals.

[0027] Figure 3 This shows a schematic diagram of the overlay between polar coordinates and a spatial map.

[0028] In all the accompanying drawings, parts that correspond to each other are always given the same reference numerals. Detailed Implementation

[0029] Figure 1 The diagram schematically illustrates a hearing aid, specifically a hearing assistive device, referred to as hearing aid 1. Hearing aid 1 includes a housing 2, which is worn on the user's head, specifically behind the ear. Hearing aid 1 also has multiple electronic components arranged within the housing 2. These electronic components include two microphones 4, a signal processor 6 (also called a "controller"), a power source 8 (specifically a rechargeable battery, including control circuitry for charging control and power supply), and a CW radar unit, referred to as a "radar chipset 10". Here, housing 2 constitutes the device base of hearing aid 1. The microphones 4 are connected to the signal processor 6, which processes (mixes, filters, amplifies, etc.) the microphone signals. The output signal generated by signal processor 6 is transmitted to speaker 12 of hearing aid 1. In this embodiment, speaker 12 is mounted within housing 2, but alternatively, it can be worn as an external speaker in the ear canal.

[0030] Signal processor 6 is configured to process the microphone signal, for example, based on the dimensions of the user's room, specifically the distance between the user and the room walls. This is because the distance between the hearing aid 1 and the walls can, for example, influence filters, such as by better adjusting or activating a so-called reverberation filter. This is done to estimate the user's surrounding environment and objects, specifically the room walls 20 (see...). Figure 3 The signal processor 6 is configured to implement the method described in the following detailed description, given the distance between the signal processor and the signal processor.

[0031] Signal processor 6 is configured to control radar chipset 10 to transmit unmodulated CW radar signals. These CW radar signals are reflected by walls and other objects within the radiation range of the transmitting antenna of radar chipset 10 (e.g., a 3dB radiation angle of 65 degrees, not shown in detail). The reflected radar signals are received by the receiving antenna of radar chipset 10 (not shown in detail). Radar chipset 10 then outputs the received radar signal to signal processor 6.

[0032] The signal processor 6 is configured to detect a portion of the radar received signal that is characterizable for the micro-Doppler effect caused by at least one of the walls 20. Furthermore, the signal processor 6 is configured to infer the distance between the object, at least one wall 20, and the hearing aid 1 based on this "characteristic" signal portion.

[0033] Therefore, signal processor 6 converts the radar received signal into its frequency representation using a Fast Fourier Transform (FFT). Since the wall 20 (or other object) is considered stationary, 0Hz (or + / - 10-20Hz if necessary) is taken as the relevant frequency for the micro-Doppler effect. Here, in the frequency representation of the radar received signal (see...),... Figure 2 The micro-Doppler effect that can be identified in the radar is caused by slight movement of the user and therefore the housing 2 (and radar chipset 10). Therefore, the micro-Doppler effect is caused not only by the movement of the "target" but also by the movement of the transmitter and / or receiver.

[0034] Figure 2 The dashed curve in the image exemplifies the FFT plot of the radar received signal when the housing 2 remains stationary and a stationary object is detected. In this case, only noise is detected. Figure 2 The case of the shell 2 worn on the head is also shown, where only stationary objects (solid lines) are detected. It can be seen that there is a peak in the radar received signal in the 0Hz range.

[0035] For 0Hz, signal processor 6 first determines the power of the radar-received signal and compares this value (also known as the digital FFT equivalent) with a table storing the corresponding distances for each power value. Here, the highest amplitude is assumed to be a wall as the object. This method is based on the consideration that walls within a room are likely to be objects with the highest reflectivity.

[0036] The hearing aid 1 also includes an inertial measurement unit 30, such as a 3D accelerometer, for detecting the orientation of the hearing aid, particularly the housing 2, in space. The signal processor 6 is configured to perform the aforementioned distance measurement between the hearing aid 1 and objects in the surrounding environment only when the inertial measurement unit 30 detects movement of the hearing aid 1. Thus, the signal processor 6 can easily determine that the micro-Doppler effect present in the radar received signal is caused by the movement of the user or at least the hearing aid 1, or particularly when the inertial measurement unit 30 does not detect user movement, for example, by the movement of large objects in the user's surrounding environment.

[0037] In addition, the signal processor 6 is configured to create a map of the space in which the hearing aid 1 is located. To this end, the signal processor 6 detects the current orientation of the hearing aid 1 in the space via the inertial measurement unit 30 and is able to determine the distance to the corresponding wall 20 based on this orientation. Figure 3 This is illustrated using a polar coordinate graph, where 0 degrees is located at the "3 o'clock position". Here, the digital FFT equivalent value is, for example, 0.0628 (assuming no units here), and 0.0623 for 180 degrees. Therefore, the user is located on the central axis of the room. For the 90-degree direction, the digital FFT equivalent value is 0.0334, and for 270 degrees, it is 0.0834. Therefore, the user's back is closer to wall 20 at that location, rather than wall 20 located at 90 degrees.

[0038] To improve accuracy, the signal processor 6 is optionally configured to average the digital FFT values ​​over a 30-second time period and perform five measurements within this time period.

[0039] The technical solutions of the present invention are not limited to the embodiments described above. Instead, those skilled in the art can deduce other embodiments of the present invention from the above description. The various features and design variations of the present invention described according to the various embodiments can also be combined in other ways.

[0040] List of reference numerals

[0041] 1 Hearing equipment

[0042] 2 Equipment casing

[0043] 4 microphones

[0044] 6 signal processors

[0045] 8 Energy

[0046] 10 radar chipsets

[0047] 12 speakers

[0048] 20 walls

[0049] 30 inertial measurement units

Claims

1. A hearing device (1), having - The device substrate worn on the user's body, especially the head (2). - CW radar unit (10), the CW radar unit being disposed within or on the device base (2) and configured to transmit unmodulated CW radar signals and receive corresponding, reflected radar signals, and - Controller (6), the controller is configured to detect the signal portion characterizing the micro-Doppler effect from the radar received signal and thereby determine the distance from the device substrate (2) to an object (20) in the user's surrounding environment, the radar received signal being given by the CW radar unit (10) based on the received reflected radar signal.

2. The hearing device (1) according to claim 1, characterized in that, The controller (6) is configured to decompose the radar received signal, at least the characteristic signal portion, into frequency components, especially by means of a fast Fourier transform.

3. The hearing device (1) according to claim 1 or 2, characterized in that, The controller (6) is configured to determine, in order to obtain the distance, the digital FFT value of the characteristic signal portion, and in particular its equivalent value.

4. The hearing device (1) according to claim 3, characterized in that, The controller (6) is configured to make the FFT value of the characteristic signal portion close to the frequency range of 0 Hz, i.e., 0+ / -20 Hz, in order to obtain the distance.

5. The hearing device (1) according to claim 3 or 4, characterized in that, The controller (6) is configured to compare the FFT value with a plurality of stored FFT comparison values, each of which is associated with a distance value, in order to obtain the distance.

6. The hearing device (1) according to any one of claims 1 to 5, characterized in that, An inertial measurement unit (30) is provided, which is disposed within or on the device base (2) and is configured and designed to determine at least a change in the orientation of the device base (2) in space, wherein the controller (6) is configured to, when the inertial measurement unit (30) determines that the orientation of the device base (2) has changed, at least subsequently determine the distance from the device base (2) to an object by means of the CW radar unit (10).

7. The hearing device (1) according to any one of claims 3 to 6, characterized in that, The controller (6) is configured to average the digital FFT values ​​over a preset time period, particularly 5 to 40 seconds, preferably 15 to 30 seconds, in order to obtain the distance.

8. The hearing device (1) according to claim 6 or 6 and 7, characterized in that, The controller (6) is configured to create an environment map based on the distance and spatial angle information determined by the inertial measurement unit (30) from the user's perspective. The environment map includes the distances between the hearing device and objects in the user's surrounding environment, particularly walls and / or other objects in the space where the user is located.

9. The hearing device (1) according to any one of claims 1 to 8, characterized in that, The controller (6) is configured to use a Kalman filter on the radar received signal in order to determine the distance.

10. The hearing device (1) according to any one of claims 1 to 9, characterized in that, The controller (6) is configured to obtain motion information about the user's body parts, especially the user's hands, based on the radar received signal, especially the frequency of the radar received signal, and to identify input instructions for changing the signal processing parameters of the hearing device (1) based on the motion information.

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