WO2017175448A1 - 信号処理装置、信号処理方法、及びプログラム - Google Patents
信号処理装置、信号処理方法、及びプログラム Download PDFInfo
- Publication number
- WO2017175448A1 WO2017175448A1 PCT/JP2017/002219 JP2017002219W WO2017175448A1 WO 2017175448 A1 WO2017175448 A1 WO 2017175448A1 JP 2017002219 W JP2017002219 W JP 2017002219W WO 2017175448 A1 WO2017175448 A1 WO 2017175448A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- sound
- acoustic device
- noise reduction
- signal
- sound collection
- Prior art date
Links
Images
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
- G10K11/17821—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the input signals only
- G10K11/17823—Reference signals, e.g. ambient acoustic environment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/80—Head-rests
- B60N2/879—Head-rests with additional features not related to head-rest positioning, e.g. heating or cooling devices or loudspeakers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
- B60R11/02—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof
- B60R11/0217—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof for loud-speakers
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
- G10K11/17813—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
- G10K11/17817—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the output signals and the error signals, i.e. secondary path
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
- G10K11/17813—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
- G10K11/17819—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the output signals and the reference signals, e.g. to prevent howling
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1785—Methods, e.g. algorithms; Devices
- G10K11/17853—Methods, e.g. algorithms; Devices of the filter
- G10K11/17854—Methods, e.g. algorithms; Devices of the filter the filter being an adaptive filter
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1785—Methods, e.g. algorithms; Devices
- G10K11/17857—Geometric disposition, e.g. placement of microphones
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1787—General system configurations
- G10K11/17875—General system configurations using an error signal without a reference signal, e.g. pure feedback
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1787—General system configurations
- G10K11/17879—General system configurations using both a reference signal and an error signal
- G10K11/17881—General system configurations using both a reference signal and an error signal the reference signal being an acoustic signal, e.g. recorded with a microphone
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
- H04R3/005—Circuits for transducers, loudspeakers or microphones for combining the signals of two or more microphones
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
- B60R2011/0001—Arrangements for holding or mounting articles, not otherwise provided for characterised by position
- B60R2011/0003—Arrangements for holding or mounting articles, not otherwise provided for characterised by position inside the vehicle
- B60R2011/0012—Seats or parts thereof
- B60R2011/0017—Head-rests
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/10—Applications
- G10K2210/128—Vehicles
- G10K2210/1282—Automobiles
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/301—Computational
- G10K2210/3019—Cross-terms between multiple in's and out's
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/321—Physical
- G10K2210/3221—Headrests, seats or the like, for personal ANC systems
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/50—Miscellaneous
- G10K2210/506—Feedback, e.g. howling
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2410/00—Microphones
- H04R2410/05—Noise reduction with a separate noise microphone
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2499/00—Aspects covered by H04R or H04S not otherwise provided for in their subgroups
- H04R2499/10—General applications
- H04R2499/13—Acoustic transducers and sound field adaptation in vehicles
Definitions
- the present disclosure relates to a signal processing device, a signal processing method, and a program.
- Patent Document 1 discloses an example of a technique called noise canceling.
- a user for example, a driver
- an in-vehicle device such as a car navigation device
- the user has a speaker installed in the vehicle.
- the user will listen to the voice guidance output from the acoustic device.
- a sound collection unit for example, a microphone
- Sound from other acoustic devices may be collected.
- the sound collection result of the sound from another acoustic device may affect the processing for reducing the noise, and may manifest as a phenomenon such as so-called howling.
- a signal processing apparatus and a signal processing method capable of reducing the influence of noise in a more preferable manner even in an environment where the user listens to the sound output in the released space. And propose a program.
- the generation unit that generates the first noise reduction signal for driving the first acoustic device that outputs the first sound for reducing noise, and the predetermined sound collection unit, The first sound propagating from the first acoustic device via the first propagation path, and the second sound propagating from the second acoustic device different from the first acoustic device via the second propagation path.
- an acquisition unit that acquires a sound collection result including the sound, and the generation unit uses the sound collection result and a second noise reduction signal for driving the second sound device.
- a signal processing apparatus that generates the first noise reduction signal based on a cancellation signal based on the cancellation signal.
- the processor generates a first noise reduction signal for driving a first acoustic device that outputs a first sound for reducing noise, and a predetermined sound collection.
- the first acoustic wave propagating from the first acoustic device via the first propagation path, and the second acoustic device different from the first acoustic device via the second propagation path.
- a signal processing method is provided that is generated based on a cancellation signal based on two noise reduction signals.
- the computer generates a first noise reduction signal for driving a first acoustic device that outputs a first sound for reducing noise, and a predetermined sound collection.
- the first acoustic wave propagating from the first acoustic device via the first propagation path, and the second acoustic device different from the first acoustic device via the second propagation path.
- a program generated based on a cancellation signal based on the second noise reduction signal is provided.
- FIG. It is explanatory drawing for demonstrating another example of the schematic structure of the noise reduction system which concerns on the modification 1.
- FIG. It is explanatory drawing for demonstrating the change of the propagation environment of the sound output from the acoustic device 11 according to the position of a user's head. It is explanatory drawing for demonstrating the change of the propagation environment of the sound output from the acoustic device 11 according to the position of a user's head. It is an example of the block diagram which paid its attention to the signal processing of the noise reduction system which concerns on the modification 1.
- FIG. It is a functional block diagram which shows one structural example of the hardware constitutions of the information processing apparatus which comprises the noise reduction system which concerns on the embodiment.
- FIGS. 1 and 2 are explanatory diagrams for describing an example of a schematic configuration of the noise reduction system according to the present embodiment.
- the user mainly listens to the sound output to the space released from the acoustic device such as a speaker, unlike when listening to the sound via headphones or earphones. It is assumed to be used in such an environment.
- the noise reduction system 1 As a specific application example of the noise reduction system 1 according to the present embodiment, a road due to a driving sound of an engine, a motor, etc., a vibration received by a vehicle from a road surface, or the like with respect to a sound or sound from an in-vehicle device such as a car navigation device. Reduction of the influence of noise such as noise can be mentioned. More specifically, in the noise reduction system 1 according to the present embodiment, the acoustic device 11 and the sound collection unit 13 are positioned in the vicinity of the left and right ears of the user U11 sitting on a seat installed in the vehicle. Is supported.
- acoustic device 11a when the acoustic device 11 and the sound collection unit 13 supported in the vicinity of the left ear of the user U11 are explicitly shown, they are referred to as “acoustic device 11a” and “sound collection unit 13a”. Similarly, when the acoustic device 11 and the sound collection unit 13 supported in the vicinity of the right ear are explicitly shown, they are referred to as “acoustic device 11b” and “sound collection unit 13b”.
- the acoustic devices 11 a and 11 b and the sound collection units 13 a and 13 b are provided on the headrest portion 81 of the seat 83 installed in the vehicle.
- FIG. 2 shows an example of the installation positions of the acoustic devices 11 and the sound collectors 13 when the acoustic devices 11a and 11b and the sound collectors 13a and 13b are installed in the vehicle.
- the upper diagram in FIG. 2 schematically shows the positional relationship among the user U11, the acoustic devices 11a and 11b, and the sound collection units 13a and 13b when the seat 83 on which the user U11 sits is viewed from above. It shows.
- the lower diagram of FIG. 2 schematically illustrates the positional relationship among the user U11, the acoustic device 11b, and the sound collecting unit 13b when the seat 83 is viewed from the right side with respect to the traveling direction of the vehicle. Is shown. In the lower diagram, the acoustic device 11a and the sound collecting unit 13a are not shown in order to make the configuration easier to understand.
- each of the acoustic devices 11 a and 11 b is installed in the headrest portion 81. More specifically, the acoustic device 11 a is installed at a position on the left side in the headrest portion 81, and the acoustic device 11 b is installed at a position on the right side in the headrest portion 81. Note that each of the acoustic devices 11a and 11b is mainly installed so that sound is output toward the front. With such a configuration, when the headrest portion 81 supports the head of the user U11, the acoustic device 11a is positioned in the vicinity of the user's left ear, and the acoustic device 11b is positioned in the vicinity of the user's right ear. It will be.
- each of the sound collecting portions 13 a and 13 b is installed so as to be exposed on the front surface of the headrest portion 81. More specifically, when the headrest part 81 supports the head of the user U11, the sound collecting part 13a is installed so as to be positioned in the vicinity of the left ear of the user U11. Similarly, the sound collection unit 13b is installed so as to be positioned in the vicinity of the right ear of the user U11 when the headrest unit 81 supports the head of the user U11. With such a configuration, the sound output from the acoustic device 11a is heard by the left ear of the user U11 and collected by the sound collection unit 13a. Similarly, the sound output from the acoustic device 11b is heard by the right ear of the user U11 and is collected by the sound collection unit 13b.
- the noise reduction system 1 Based on the configuration as described above, the noise reduction system 1 according to the present embodiment performs noise reduction processing based on a so-called feedback (FB) method to reduce noise to the sound output from each of the acoustic devices 11a and 11b. Reduce the impact.
- FB feedback
- FIGS. 1 and 2 An example of a schematic configuration of a noise reduction system according to an embodiment of the present disclosure has been described with reference to FIGS. 1 and 2.
- reference symbol F 1 schematically shows a transfer function of the propagation environment until the sound output from the acoustic device 11 reaches the sound collection unit 13.
- Reference symbol d indicates noise from the surrounding environment. That is, in the example illustrated in FIG. 3, the sound collection unit 13 collects the sound output from the acoustic device 11 and the noise d.
- Reference symbol ⁇ represents a filter coefficient when generating a noise reduction signal based on the sound collection result of the sound collected by the sound collection unit 13.
- the noise reduction processing based on the FB method is aimed at noise reduction (and thus mute) at the position of the sound collection unit 13, and the effect of noise reduction is limited to the vicinity of the sound collection unit 13. Is done. That is, ideally, in order to improve the noise reduction effect at the position of the listener's (user) head (the eardrum), it is more desirable to install the sound collection unit 13 at a position close to the eardrum. Note that, as the distance between the acoustic device 11 and the sound collecting unit 13 is further increased, the phase rotation due to the time delay becomes larger, and thus control of the noise reduction process tends to be difficult. Therefore, it is more desirable that the sound collection unit 13 be installed in the vicinity of the acoustic device 11.
- a series for noise reduction in the case of causing the user's left ear and right ear to listen to sounds from different acoustic devices 11a and 11b as in the noise reduction system 1 according to the present embodiment, a series for noise reduction.
- An example of a system in which a plurality of noise reduction systems based on the FB method (that is, feedback systems) are provided will be described as a comparative example with reference to FIGS. 4 and 5.
- FIG. 4 schematically shows an ideal operation situation when a plurality of systems for noise reduction based on the FB method are provided.
- the acoustic devices 11 a and 11 b and the sound collection units 13 a and 13 b with respect to the headrest portion 81 are the same as the noise reduction system 1 shown in FIGS. 1 and 2. And are installed. That is, the acoustic device 11a and the sound collection unit 13a are supported near the left ear of the user U11, and the acoustic device 11b and the sound collection unit 13b are supported near the right ear of the user U11.
- the system 9 also includes feedback noise cancellation filters (hereinafter also referred to as “FB-NC filters”) 101a and 101b.
- the FB-NC filters 101a and 101b are configured to generate a noise reduction signal. More specifically, the FB-NC filter 101a is for driving the acoustic device 11a to output sound for reducing noise from the acoustic device 11a based on the sound collection result by the sound collection unit 13a. Generate a noise reduction signal. That is, the acoustic device 11a, the sound collecting unit 13a, and the FB-NC filter 101a correspond to a series of feedback systems for providing a noise reduction effect in the vicinity of the left ear of the user U11.
- the FB-NC filter 101b is a noise reduction signal for driving the acoustic device 11b to output sound for reducing noise from the acoustic device 11b based on the sound collection result by the sound collection unit 13b. Is generated. That is, the acoustic device 11b, the sound collection unit 13b, and the FB-NC filter 101b correspond to a series of feedback systems for providing a noise reduction effect in the vicinity of the right ear of the user U11.
- the system 9 ideally includes a left ear system (an acoustic device 11a, a sound collection unit 13a, and an FB-NC filter 101a) and a right ear side. It is desirable that the system (the acoustic device 11b, the sound collecting unit 13b, and the FB-NC filter 101b) operate independently. More specifically, in the example shown in FIG. 4, the noise reduction signal generated by the FB-NC filter 101a based on the sound collection result by the sound collection unit 13a drives the acoustic device 11a.
- the sound based on the noise reduction signal is output from the acoustic device 11a, and the sound propagates through the space near the left ear of the user U11 and is collected by the sound collecting unit 13a. That is, ideally, a feedback closed loop is formed by the acoustic device 11a, the sound collection unit 13a, and the FB-NC filter 101a.
- the noise reduction signal generated by the FB-NC filter 101b based on the sound collection result by the sound collection unit 13b drives the acoustic device 11b.
- the sound based on the noise reduction signal is output from the acoustic device 11b, and the sound propagates through the space near the right ear of the user U11 and is collected by the sound collecting unit 13b.
- a closed loop of feedback is formed by the acoustic device 11b, the sound collection unit 13b, and the FB-NC filter 101b.
- the left ear system and the right ear system described above are not necessarily operable independently.
- sound for reducing noise output from the left ear-side acoustic device 11 a is collected by the right ear-side sound collecting unit 13 b.
- a noise reduction signal is generated by performing noise reduction processing on the sound signal based on the sound collection result of the sound by the sound collection unit 13b by the FB-NC filter 101b.
- the ear-side acoustic device 11b is driven.
- the sound based on the noise reduction signal is output from the acoustic device 11b.
- sound for reducing noise output from the acoustic device 11b is collected by the sound collecting unit 13a on the left ear side, as shown in FIG. Will be formed. Since the 8-shaped closed loop shown in FIG. 5 reduces the independence of the feedback system (for example, the independence of the right ear system and the left ear system), the noise reduction effect is reduced. As a result, there is a possibility of manifesting a phenomenon called howling.
- the present disclosure suppresses the influence associated with the formation of the 8-shaped closed loop as described above, which may occur in an environment where the user listens to the sound output in the released space, and is more preferable.
- An example of a mechanism capable of reducing the influence of noise in an aspect is proposed.
- FIG. 6 is a block diagram illustrating an example of a functional configuration of the noise reduction system 1 according to the present embodiment.
- the noise reduction system 1 includes acoustic devices 11a and 11b, sound collection units 13a and 13b, FB-NC filters 101a and 101b, power amplifiers 103a and 103b, and a microphone.
- Amplifiers 105a and 105b, subtracters 107a and 107b, and loop cancellers 109a and 109b are included.
- the acoustic devices 11a and 11b and the sound collecting units 13a and 13b correspond to the acoustic devices 11a and 11b and the sound collecting units 13a and 13b shown in FIGS.
- the power amplifiers 103a and 103b and the microphone amplifiers 105a and 105b correspond to so-called amplifiers for adjusting the gain of the acoustic signal.
- the gain of the sound signal based on the sound collection result by the sound collection unit 13a is adjusted by the microphone amplifier 105a and is input to the subtractor 107a.
- the subtracter 107a receives a cancel signal output from a loop canceller 109a described later.
- the subtractor 107a subtracts the cancellation signal output from the loop canceller 109a from the acoustic signal output from the microphone amplifier 105a (that is, the acoustic signal based on the sound collection result of the sound collection unit 13a), and is obtained as a subtraction result.
- An acoustic signal is input to the FB-NC filter 101a.
- the FB-NC filter 101a generates a noise reduction signal by performing noise reduction processing on the input acoustic signal according to the characteristics of the propagation environment between the acoustic device 11a and the sound collection unit 13a.
- the noise reduction signal is output as a drive signal for driving the acoustic device 11a. That is, the gain of the noise reduction signal output from the FB-NC filter 101a is adjusted by the power amplifier 103a to drive the acoustic device 11a.
- a part of the noise reduction signal output from the FB-NC filter 101a is demultiplexed by a splitter or the like and input to the loop canceller 109b.
- the sound signal based on the sound collection result by the sound collection unit 13b is adjusted in gain by the microphone amplifier 105b and input to the subtractor 107b. Further, a cancel signal output from a loop canceller 109b described later is input to the subtractor 107b.
- the subtractor 107b subtracts the cancellation signal output from the loop canceller 109b from the acoustic signal output from the microphone amplifier 105b (that is, the acoustic signal based on the sound collection result of the sound collection unit 13b), and is obtained as a subtraction result.
- An acoustic signal is input to the FB-NC filter 101b.
- the FB-NC filter 101b performs a noise reduction process on the input acoustic signal according to the characteristics of the propagation environment between the acoustic device 11b and the sound collection unit 13b to generate a noise reduction signal.
- the noise reduction signal is output as a drive signal for driving the acoustic device 11a. That is, the gain of the noise reduction signal output from the FB-NC filter 101b is adjusted by the power amplifier 103b to drive the acoustic device 11b.
- a part of the noise reduction signal output from the FB-NC filter 101b is demultiplexed by a splitter or the like and input to the loop canceller 109a.
- the loop cancellers 109a and 109b generate a cancel signal for reducing the influence associated with the formation of the 8-shaped closed loop described with reference to FIG.
- the loop canceller 109a receives the noise reduction signal output from the FB-NC filter 101b as an input, and reduces the influence of the formation of the 8-shaped closed loop on the sound output from the acoustic device 11a. To generate a cancel signal.
- the loop canceller 109b receives the noise reduction signal output from the FB-NC filter 101a as an input to reduce the influence of the formation of the 8-shaped closed loop on the sound output from the acoustic device 11b.
- a cancel signal is generated.
- the details of the processing related to the generation of the cancel signal by the loop cancellers 109a and 109b will be separately described later together with the description of the signal processing by the noise reduction system 1 according to the present embodiment.
- the functional configuration of the noise reduction system 1 described above is merely an example, and is not necessarily limited to the configuration illustrated in FIG.
- at least one of the acoustic devices 11a and 11b and the sound collecting units 13a and 13b may be configured as an external device.
- the FB-NC filter 101a, the power amplifier 103a, the microphone amplifier 105a, the subtractor 107a, and the loop canceller 109a, and the FB-NC filter 101b, the power amplifier 103b, the microphone amplifier 105b, the subtractor 107b, and the loop canceller 109b are provided. They may be provided in different devices.
- the configuration including the FB-NC filter 101a, the subtractor 107a, and the loop canceller 109a, and the FB-NC filter 101b, the subtractor 107b, and the loop canceller 109b corresponds to an example of a “signal processing device”.
- FIG. 7 shows an example of a block diagram focusing on signal processing of the noise reduction system 1 according to the present embodiment.
- the power amplifiers 103a and 103b and the microphone amplifiers 105a and 105b shown in FIG. 6 are shown in order to make the characteristics of signal processing in the noise reduction system 1 according to the present embodiment easier to understand.
- the illustration is omitted.
- reference numeral F 1 is an acoustic output from the acoustic device 11a has a transfer function showing the spatial characteristics of the propagation environment to reach the sound collecting portion 13a schematically.
- reference numeral F 2 is the acoustic output from the acoustic device 11b is shows the transfer function representing the spatial characteristics of the propagation environment to reach the sound collecting portion 13b schematically.
- reference numeral G 1 is an acoustic output from the acoustic device 11a has a transfer function showing the spatial characteristics of the propagation environment to reach the sound collecting portion 13b schematically.
- reference numeral G 2 is the acoustic output from the acoustic device 11b is shows the transfer function representing the spatial characteristics of the propagation environment to reach the sound collecting portion 13a schematically.
- Reference numerals d 1 and d 2 schematically indicate noise collected by the sound collecting units 13a and 13b, respectively.
- Reference symbols ⁇ 1 and ⁇ 2 schematically represent filter coefficients for generating a noise reduction signal by performing noise reduction processing on the acoustic signals input to the FB-NC filters 101a and 101b, respectively.
- Reference symbol G ′ 1 schematically indicates a filter coefficient for generating a cancel signal to be input to the subtractor 107 b by the loop canceller 109 b performing filter processing on the input noise reduction signal.
- reference symbol G ′ 2 schematically represents a filter coefficient for generating a cancel signal to be input to the subtractor 107 a by the loop canceller 109 a performing filter processing on the input noise reduction signal. Show.
- the sound output from the acoustic device 11a is y
- the sound output from the acoustic device 11b is z.
- the sound y corresponds to the sound output by driving the sound device 11a based on the noise reduction signal from the FB-NC filter 101a.
- the sound z corresponds to sound output by driving the sound device 11b based on the noise reduction signal from the FB-NC filter 101b.
- the sound y is expressed by the following (Formula 2).
- the sound output from the acoustic device 11a and collected by the sound collection unit 13a is “first sound”. It corresponds to an example.
- the sound output from the acoustic device 11b and collected by the sound collecting unit 13a corresponds to an example of “second sound”.
- the propagation path (propagation environment) between the acoustic device 11a and the sound collection unit 13a corresponds to an example of “first propagation path”
- the propagation path between the acoustic device 11b and the sound collection unit 13a (Propagation environment) corresponds to an example of “second propagation path”.
- the noise reduction signal for driving the acoustic device 11a corresponds to an example of “first noise reduction signal”
- the noise reduction signal for driving the acoustic device 11b is “second noise reduction signal”. It corresponds to an example.
- the acoustic y output from the acoustic device 11a has been described.
- the acoustic z output from the acoustic device 11b is also influenced by the acoustic y output from the acoustic device 11a based on the same idea. Can be excluded.
- the conditions of the positional relationship among the acoustic device 11, the sound collection unit 13, and the listener's ears to obtain a noise reduction effect in a more preferable manner I will consider in more detail.
- the phase rotation due to the time delay becomes larger as the distance between the acoustic device 11 and the sound collecting unit 13 is further increased. Tend to be difficult to control.
- the acoustic device 11 and the sound collection unit 13 are installed so that the phase rotation caused by the time delay is limited to a predetermined value (threshold value) or less, thereby providing a noise reduction effect in a more preferable manner. Can be obtained.
- FIG. 8 is a graph showing an example of a simulation result of the relationship between the degree of phase mismatch and the effect of noise reduction processing.
- the horizontal axis indicates the degree of amplitude mismatch as a percentage
- the vertical axis indicates the effect of noise reduction processing (that is, the amount of noise reduction) as gain (dB).
- a graph showing characteristics between the degree of amplitude mismatch according to the phase shift and the effect of the noise reduction processing is shown in 5 deg increments in the range where the phase shift is 0 to 45 deg. Yes.
- the effect of the noise reduction process is 15 dB at the maximum regardless of the amplitude.
- phase rotation caused by the time delay that is, the phase rotation caused by the distance between the acoustic device 11 and the sound collecting unit 13
- FIG. 9 is a graph illustrating an example of a simulation result regarding a phase change according to the distance between the acoustic device 11 and the sound collection unit 13.
- the horizontal axis indicates the frequency of sound that propagates between the acoustic device 11 and the sound collection unit 13
- the vertical axis indicates the phase of the sound.
- the acoustic wave propagating between the acoustic device 11 and the sound collecting unit 13 is obtained when the distance between the acoustic device 11 and the sound collecting unit 13 is 11 cm, 13 cm, and 15 cm, respectively.
- the simulation result regarding the change of the phase is shown.
- the acoustic device 11 and the sound collecting device are obtained from the simulation result shown in FIG.
- the limit of the distance between the part 13 is 15 cm.
- FIG. 10 is an explanatory diagram for explaining the conditions of the installation positions of the acoustic device 11 and the sound collecting unit 13.
- reference symbol L ⁇ b> 11 indicates the distance between the acoustic device 11 and the sound collection unit 13 that form a closed loop of feedback.
- the limit of the distance L11 is 15 cm as described above.
- the ear U13 is an acoustic device. It is desirable to be located inside the region R15 having a radius of 15 cm with 11 as the center.
- each of the acoustic device 11 and the sound collection unit 13 performs phase rotation of the sound for reducing noise output from the acoustic device 11 at each position of the sound collection unit 13 and the listener's ear U13.
- both are installed in a positional relationship such that both are 45 degrees or less. More specifically, as shown in FIG. 10, the acoustic device 11 so that both the sound collection unit 13 and the listener's ear U13 are located within a predetermined distance L11 with respect to the acoustic device 11. And each of the sound collection parts 13 should just be installed.
- the distance L11 is determined according to the upper limit of the acoustic frequency for reducing noise and the allowable amount of phase rotation caused by the time delay. As a specific example, as described above, if the phase rotation due to the time delay is 45 degrees or less and the upper limit of the acoustic frequency for reducing noise is 300 Hz, the limit of the distance L11 is 15 cm.
- the installation positions of the acoustic device 11 and the sound collection unit 13 are not particularly limited.
- FIG.11 and FIG.12 is explanatory drawing for demonstrating an example of the schematic structure of the noise reduction system which concerns on this embodiment. Specifically, each acoustic device 11 and each sound collector in the case where the acoustic devices 11a and 11b and the sound collectors 13a and 13b described with reference to FIGS. The other example of 13 installation positions is shown. 11 and FIG.
- FIGS. 12 are diagrams between the user U11, the acoustic devices 11a and 11b, and the sound collection units 13a and 13b when the seat 83 on which the user U11 sits is viewed from above.
- the positional relationship is schematically shown.
- 11 and 12 show the positions between the user U11, the acoustic device 11b, and the sound collection unit 13b when the seat 83 is viewed from the right side with respect to the traveling direction of the vehicle.
- the relationship is schematically shown. 11 and 12, illustration of the acoustic device 11a and the sound collection unit 13a is omitted for easier understanding of the configuration.
- each of the acoustic devices 11a and 11b is located behind the head of the user U11 and installed so that sound is output toward the front.
- each of the acoustic devices 11a and 11b is located above the head of the user U11 (for example, the ceiling of the vehicle), and the direction of the head of the user U11 (ie, the head) It is installed so that sound is output toward the lower part.
- each of the sound collection units 13a and 13b may be installed near the left and right ears of the user U11 so as to collect sound coming from above.
- the acoustic devices 11a and 11b are positioned in different directions on the left and right with respect to the head of the user U11, and the direction of the head of the user U11 (ie, from the outside to the inside). It is installed so that the sound is output in the direction (toward).
- each of the sound collection units 13a and 13b is located in the vicinity of the left and right ears of the user U11, and is installed so as to collect sound coming from the left and right sides of the head of the user U11. Good.
- FIG. 13 is an explanatory diagram for describing an example of a schematic configuration of a noise reduction system according to the first modification.
- the noise reduction system shown in FIG. 13 may be referred to as “noise reduction system 2” in order to distinguish it from the noise reduction system 1 described above.
- the noise reduction system 2 is different from the noise reduction system 1 described with reference to FIG. 6 in the configuration of the loop cancellers 209a and 209b. That is, the acoustic devices 11a and 11b and the sound collecting units 13a and 13b shown in FIG. 13 are respectively connected to the acoustic devices 11a and 11b and the sound collecting units 13a and 13b in the noise reduction system 1 shown in FIG. Equivalent to.
- the FB-NC filters 201a and 201b, the power amplifiers 203a and 203b, the microphone amplifiers 205a and 205b, and the subtractors 207a and 207 are the FB-NC filter 101a in the noise reduction system 1 shown in FIG.
- adaptive filters such as so-called FIR (Finite Impulse Response) filters are applied as the loop cancellers 209a and 209b.
- FIR Finite Impulse Response
- the loop canceller 209a according to changes in the environment in which the sound output from the acoustic devices 11a and 11b propagates, changes in the positions of the acoustic devices 11a and 11b with respect to the left and right ears of the user, and the like. And 209b can be changed.
- the noise reduction system 2 shown in FIG. 13 operates according to the characteristics of the adaptive filters used as the loop cancellers 209a and 209b when the correlation between the sounds output from the acoustic devices 11a and 11b is high.
- the stability of the may decrease.
- an adaptive filter such as an FIR filter
- the number of filter taps may increase, and as a result, calculation resources may increase.
- FIG. 14 is an explanatory diagram for describing another example of the schematic configuration of the noise reduction system according to the first modification.
- the noise reduction system shown in FIG. 14 may be referred to as “noise reduction system 3” in order to distinguish from the noise reduction systems 1 and 2 described above.
- the noise reduction system 3 is the noise reduction system described with reference to FIG. 6 in terms of the configuration of the filter banks 301 a, 301 b, 309 a, and 309 b and the point including the head position estimation unit 35. Different from 1. That is, the acoustic devices 11a and 11b and the sound collecting units 13a and 13b shown in FIG. 14 are respectively connected to the acoustic devices 11a and 11b and the sound collecting units 13a and 13b in the noise reduction system 1 shown in FIG. Equivalent to.
- the power amplifiers 303a and 303b, the microphone amplifiers 305a and 305b, and the subtractors 307a and 307 are the FB-NC filters 101a and 101b, and the power amplifiers 103a and 103b in the noise reduction system 1 shown in FIG. And microphone amplifiers 105a and 105b and subtracters 107a and 107. Therefore, in the present description, the configuration of the noise reduction system 3 will be described with particular attention to parts that are different from the noise reduction system 1 described above, and detailed description of substantially the same parts will be omitted.
- the filter banks 301a and 301b correspond to the FB-NC filters 101a and 101b in the noise reduction system 1 described with reference to FIG. Since the filter banks 301a and 301b have the same configuration, the configuration of the filter bank 301a will be described here, and the detailed description of the filter bank 301b will be omitted.
- the filter bank 301a includes a plurality of FB-NC filters C 1 to C N having different characteristics from each other, and is configured to be able to selectively switch the FB-NC filters C 1 to C N. Yes.
- the configurations of the plurality of FB-NC filters C 1 to C N are the same as those of the FB-NC filters 101a and 101b described above except for the difference in characteristics.
- the filter bank 301a has the FB-NC filters C 1 to C N according to the spatial characteristics of the propagation environment until the sound output from the acoustic device 11a reaches the sound collection unit 13a. Either can be selectively applied.
- each of the FB-NC filters C 1 to C N may be set by a prior experiment or the like according to an assumed usage scene of the noise reduction system 3. Specifically, the spatial characteristic between the acoustic device 11a and the sound collection unit 13a in each usage scene is measured in advance, and the filter coefficient is calculated based on the measurement result of the spatial characteristic, thereby corresponding to the usage scene.
- the FB-NC filter to be set may be set.
- the filter banks 309a and 309b correspond to the loop cancellers 109a and 109b in the noise reduction system 1 described with reference to FIG. Since the filter banks 309a and 309b have the same configuration, the configuration of the filter bank 309a will be described here, and the detailed description of the filter bank 309b will be omitted.
- the filter bank 309a is configured from each other includes a plurality of different loops canceller L 1 ⁇ L M characteristics, can be switched to the loop canceller L 1 ⁇ L M selectively.
- each of the configuration of a plurality of loops canceller L 1 ⁇ L M is the same as the loop canceller 109a and 109b described above, except the difference in characteristics.
- the filter bank 309a is one of the loop cancellers L 1 to L M depending on the spatial characteristics of the propagation environment until the sound output from the acoustic device 11a reaches the sound collection unit 13b. Can be selectively applied.
- each of the loop cancellers L 1 to L M may be set by a prior experiment or the like according to an assumed usage scene of the noise reduction system 3. Specifically, the spatial characteristic between the acoustic device 11a and the sound collection unit 13b in each usage scene is measured in advance, and the filter coefficient is calculated based on the measurement result of the spatial characteristic, thereby corresponding to the usage scene. You just have to set a loop canceller.
- the head position estimation unit 35 is configured to estimate the position of the user's head based on detection results of various sensors and the like.
- the head position estimation unit 35 controls the switching of the loop canceller in the filter banks 309a and 309b based on the estimation result of the position of the user's head. Note that a more detailed configuration for estimating the position of the user's head will be described later with a specific example.
- FIG. 15 shows an example in the case where the head of the user U11 is close to the headrest portion 81 where the acoustic devices 11a and 11b are installed.
- FIG. 16 shows an example in which the head of the user U11 is separated from the headrest portion 81 where the acoustic devices 11a and 11b are installed.
- the position of the head of the user U11 is estimated by measuring the distance from a predetermined position of the headrest portion 81 to the head of the user U11.
- the reference symbol L21 in FIG. 15 and the reference symbol L23 in FIG. 16 indicate the distance from a predetermined position of the headrest portion 81 to the head of the user U11. Note that the distance L21 shown in FIG. 15 and the distance L23 shown in FIG. 16 are in a relationship of L23> L21.
- the head is interposed between the acoustic device 11a and the sound collection unit 13b.
- the transfer function of the propagation environment between the acoustic device 11a and the sound collecting portion 13b at this time is F 1.
- the transfer function of the propagation environment between the acoustic device 11a and the sound collecting portion 13b at this time is F 2.
- the noise reduction system 3 illustrated in FIG. 14 selects a loop canceller corresponding to the transfer function F 1 .
- the noise reduction system 3 selects the loop canceller in accordance with the transfer function F 2.
- the noise reduction system 3 when the transfer function of the propagation environment between the acoustic device 11b and sound collector 13a and G 2, the noise reduction system 3, a loop canceller in accordance with the transfer function G 2 select.
- the head position estimation unit 35 may control switching of the NC-FB filters in the filter banks 301a and 301b based on the estimation result of the user's head position.
- the description has been made mainly focusing on the change in the spatial characteristics according to the position of the head of the user U11.
- the factors that change the spatial characteristics between the acoustic device 11 and the sound collection unit 13 are not necessarily limited. It is not limited only to the position of the head of the user U11.
- the head position estimation unit 35 acquires information indicating the open / closed state of windows and doors via a CAN (Controller Area Network), and uses the acquired information together with the estimation result of the position of the head.
- a loop canceller or an NC-FB filter may be selected.
- each of the filter banks 301a, 301b, 309a, and 309b is as above-mentioned.
- the configuration is not limited to selectively switching a plurality of filters. Specifically, it is only necessary that at least one of the gain and phase of the input acoustic signal can be controlled according to the spatial characteristics between the acoustic device 11 and the sound collection unit 13. Therefore, a configuration capable of controlling gain, such as a variable gain amplifier and a variable resistor, may be applied as at least one of the filter banks 301a, 301b, 309a, and 309b.
- the term “filtering process” refers to a process for controlling at least one of the gain and phase of an input signal.
- the above-described NC ⁇ is used instead of the filter banks 301a and 301b.
- FB filters 101a and 101b may be provided.
- FIG. 17 shows an example of a block diagram focusing on signal processing of the noise reduction system 3 according to the first modification.
- the power amplifiers 303a and 303b and the microphone amplifiers 305a and 305b shown in FIG. 14 are shown in order to make the characteristics of signal processing in the noise reduction system 3 according to the modification 1 easier to understand.
- the illustration is omitted.
- reference symbol H 1 schematically shows a transfer function indicating the spatial characteristics of the propagation environment until the sound output from the acoustic device 11 a reaches the head of the user U 11.
- the head (ear) of the user U11 is schematically illustrated as a sound collection unit.
- reference numeral H 2 an acoustic output from the acoustic device 11b is shows the transfer function representing the spatial characteristics of the propagation environment to reach the head of the user U11 schematically.
- the transfer functions H 1 and H 2 the spatial characteristics corresponding to the position of the head of the user U11 may be measured in advance, and calculated in advance based on the measurement results of the spatial characteristics.
- Reference numeral d 3 indicates the noise heard by the user U11 schematically.
- reference symbols F 1 , F 2 , G 1 , G 2 , ⁇ 1 , ⁇ 2 , G ′ 1 , G ′ 2 , d 1 , and d 2 are examples shown in FIG. Since the same content is shown, detailed description is abbreviate
- the noises d 1 , d 2, and d 3 it is more desirable to include an amplitude difference and a phase difference due to standing waves, for example, considering that the space in the vehicle is a sealed space. .
- These pieces of information may be calculated based on the results of prior measurements, simulations, etc. and stored in a desired recording unit.
- estimation may be performed by using a sound pressure estimation technique such as a so-called virtual microphone.
- FIGS. 18 to 21 are explanatory diagrams for explaining an example of a configuration and a method for estimating the head position of the user U11.
- a light source 351 such as a laser toward the head of the user U11
- reflected light is received by the light receiving element 352.
- the distance from the head (for example, the position of the headrest portion 81) to the head is estimated.
- an estimation method based on a so-called triangulation method or a time flight method is given. It is done.
- an image of the head of the user U11 is captured by the imaging units 353a and 353b such as a camera module, and image analysis is performed on the captured image so that a predetermined reference position can be obtained.
- Estimate the distance to the head is not particularly limited, and the type of the imaging unit is not limited.
- the distance to the head of the user U11 may be estimated based on information obtained based on monocular measurement.
- the distance to the head of the user U11 may be estimated based on the parallax between images captured by the compound eye camera.
- an ultrasonic wave is emitted from the ultrasonic speaker 354 and the ultrasonic wave is collected by the sound collecting unit 355, so that the ultrasonic wave is collected from a predetermined reference position based on the sound collection result of the ultrasonic wave.
- Estimate the distance to the head For example, FIG. 20 is configured as a so-called reflection type, and the sound collection unit 355 collects ultrasonic waves (that is, reflected waves) emitted from the ultrasonic speaker 354 and reflected by the head of the user U11. The distance from the predetermined reference position to the head is estimated based on the sound collection result of the reflected wave. As another example, the distance to the head of the user U11 may be estimated based on a so-called transmission method.
- the transmission method is a method for estimating from the attenuation or shielding amount of the ultrasonic beam between the transmitter and the receiver.
- a measurement signal such as white noise or TSP (Time Stretched Pulse) is output from the acoustic devices 356a and 356b provided in the headrest portion 81, and the measurement signal is a device worn by the user U11.
- the sound is collected by the sound collecting unit 357 provided in the.
- An example of a device provided with the sound collection unit 357 is a head-mounted wearable device such as a glasses-type display device.
- information limited to the head position at the timing of measurement is measured. Therefore, for example, information associated with movement of the head from the initial position may be obtained by following the head position by combining detection results from various sensors such as a gyro sensor.
- FIG. 22 is an explanatory diagram for explaining the outline of the noise reduction system according to the second modification, and controls the switching of the loop canceller in the filter bank 309 based on the estimation result by the head position estimation unit 35.
- An example is shown. In the present description, for example, by focusing described case of switching from the loop canceller L 1 loop canceller L M.
- the loop canceller L 1 which is a switching source
- both the loop canceller L M as a switching destination
- the signals output from the loop cancellers L 1 and L M are added by the adder 313 and output after the volumes are controlled by the faders 311-1 and 311-2.
- FIG. 23 is an explanatory diagram for explaining the cross fade, and shows an example of volume control by the faders 311-1 and 311-2.
- the horizontal axis indicates time, and the vertical axis indicates the amplitude of each fader.
- the data indicated as "Fader1" corresponds to the loop canceller L connected fader 311-1 to 1 as the switching source.
- the data indicated as "Fader2” corresponds to the loop canceller L fader 311-2 connected to the M as a switching destination.
- Modification 2 an example of control in the case of switching the FB-NC filter and the loop canceller in the noise reduction system 3 described above has been described with reference to FIGS. 22 and 23.
- FIG. 24 is an explanatory diagram for describing a noise reduction system according to Modification 3, and is a block diagram that focuses on signal processing of the noise reduction system.
- the noise reduction system shown in FIG. 24 is an explanatory diagram for describing a noise reduction system according to Modification 3, and is a block diagram that focuses on signal processing of the noise reduction system.
- noise reduction system 4 may be referred to as “noise reduction system 4” in order to distinguish it from the noise reduction systems according to the above-described embodiments and modifications.
- feedback system a system that forms a closed loop of feedback for noise reduction processing is shown.
- the noise reduction system 4 includes acoustic devices 11a to 11c, sound collection units 13a to 13c, NC-FB filters 401a to 401c, subtractors 407a to 407c, loop cancellers 409a to 409f, including.
- acoustic device 11a, the sound collection unit 13a, and the NC-FB filter 401a form a feedback system.
- the acoustic device 11b, the sound collection unit 13b, and the NC-FB filter 401b, and the acoustic device 11c, the sound collection unit 13c, and the NC-FB filter 401c each form a feedback system.
- Reference numerals F 1 to F 3 schematically indicate transfer functions of the propagation environment until the sound output from each acoustic device 11 reaches the sound collection unit 13 that forms a feedback system together with the acoustic device 11. ing.
- a transfer function F 3 shows the transfer function of the propagation environment between the acoustic device 11c and the sound collector 13c.
- Reference numerals G 12 , G 13 , G 21 , G 23 , G 31 , and G 32 are the sound collection unit 13 in which the sound output from each acoustic device 11 forms a feedback system together with the acoustic device 11.
- the transfer function of the propagation environment until it reaches another different sound collecting unit 13 is schematically shown.
- the transfer function G 12 shows the transfer function of the propagation environment between the acoustic device 11a and sound collector 13b
- the transfer function G 13 is, between the acoustic device 11a and sound collector 13c
- the transfer function of the propagation environment is shown.
- the transfer function G 21 shows the transfer function of the propagation environment between the acoustic device 11b and sound collector 13a
- the transfer function G 23 is, the propagation environment between the acoustic device 11b and sound collector 13c
- the transfer function is shown.
- the transfer function G 31 shows the transfer function of the propagation environment between the acoustic device 11c and the sound collector 13a
- the transfer function G 32 is, the propagation environment between the acoustic device 11c and the sound collector 13b
- the transfer function is shown.
- Reference symbols ⁇ 1 to ⁇ 3 schematically indicate filter coefficients for the FB-NC filters 401a to 401c to generate the noise reduction signal described above. Further, reference numeral G '12, G' 13, G '21, G' 23, G '31 and G,' 32, the loop canceller 409e, 409c, 409a, 409f, 409d, and each 409b is described above The filter coefficient for producing
- the sound output from the acoustic device 11a is collected by the sound collection unit 13a, and an acoustic signal based on the sound collection result is input to the subtractor 407a.
- the subtracter 407a receives a cancel signal output from each of the loop cancellers 409a and 409d.
- the subtractor 407a subtracts the cancel signal output from each of the loop cancellers 409b and 409d from the acoustic signal based on the sound collection result by the sound collection unit 13a, and inputs the acoustic signal obtained as the subtraction result to the FB-NC filter 401a. To do.
- the FB-NC filter 401a performs noise reduction processing on the input acoustic signal by performing noise reduction processing according to the characteristics of the propagation environment (transfer function F 1 ) between the acoustic device 11a and the sound collection unit 13a. A signal is generated and the noise reduction signal is output as a drive signal for driving the acoustic device 11a. Further, a part of the noise reduction signal output from the FB-NC filter 401a is demultiplexed by a splitter or the like and is input to each of the loop cancellers 409c and 409e.
- the sound output from the acoustic device 11b is collected by the sound collection unit 13b, and an acoustic signal based on the sound collection result is input to the subtractor 407b.
- a cancel signal output from each of the loop cancellers 409b and 409e is input to the subtractor 407b.
- the subtractor 407b subtracts the cancel signal output from each of the loop cancellers 409b and 409e from the sound signal based on the sound collection result by the sound collection unit 13b, and inputs the sound signal obtained as the subtraction result to the FB-NC filter 401b. To do.
- the FB-NC filter 401b performs noise reduction processing on the input acoustic signal by performing noise reduction processing according to the characteristics of the propagation environment (transfer function F 2 ) between the acoustic device 11b and the sound collection unit 13b. A signal is generated and the noise reduction signal is output as a drive signal for driving the acoustic device 11b. Further, a part of the noise reduction signal output from the FB-NC filter 401b is demultiplexed by a splitter or the like, and is input to each of the loop cancellers 409a and 409f.
- the sound output from the acoustic device 11c is collected by the sound collection unit 13c, and an acoustic signal based on the sound collection result is input to the subtractor 407c.
- a cancel signal output from each of the loop cancellers 409c and 409f is input to the subtractor 407c.
- the subtractor 407c subtracts the cancel signal output from each of the loop cancellers 409c and 409f from the sound signal based on the sound collection result by the sound collection unit 13c, and inputs the sound signal obtained as the subtraction result to the FB-NC filter 401c. To do.
- the FB-NC filter 401c performs noise reduction processing on the input acoustic signal by performing noise reduction processing according to the characteristics of the propagation environment (transfer function F 3 ) between the acoustic device 11c and the sound collection unit 13c. A signal is generated and the noise reduction signal is output as a drive signal for driving the acoustic device 11c.
- the noise reduction signal output from the FB-NC filter 401c is partly demultiplexed by a splitter or the like and input to each of the loop cancellers 409b and 409d.
- the characteristic (transfer function G ′ 21 ) of the loop canceller 409a is set so as to substantially match the spatial characteristic G 21, and the characteristic (transfer function G ′ 31 ) of the loop canceller 409d is set to the spatial characteristic G 31. Set to approximately match.
- the characteristic (transfer function G ′ 32 ) of the loop canceller 409 b is set so as to substantially match the spatial characteristic G 32, and the characteristic (transfer function G ′ 12 ) of the loop canceller 409 e is set to the spatial characteristic G 12. Set to approximately match.
- the characteristic (transfer function G ′ 13 ) of the loop canceller 409 c is set so as to substantially match the spatial characteristic G 13
- the characteristic (transfer function G ′ 23 ) of the loop canceller 409 f is set to the spatial characteristic G 23. Set to approximately match.
- a noise reduction system may be configured based on the same idea. That is, for each propagation environment between each of the plurality of acoustic devices 11 and each of the plurality of sound collection units 13, a loop canceller for generating a cancel signal according to the characteristics of the propagation environment may be provided.
- At least a part of two or more of the plurality of feedback systems may be selectively operated.
- a plurality of feedback systems are provided so that three or more acoustic devices 11 are arranged around the user.
- a feedback system for reducing noise is operated in the vicinity of the right and left ears of the user, and other feedback systems are operated. May be stopped.
- FIG. 25 is a functional block diagram illustrating a configuration example of the hardware configuration of the information processing apparatus 900 configuring the noise reduction system 1 according to an embodiment of the present disclosure.
- the information processing apparatus 900 constituting the noise reduction system 1 mainly includes a CPU 901, a ROM 903, and a RAM 905.
- the information processing apparatus 900 further includes a host bus 907, a bridge 909, an external bus 911, an interface 913, an input device 915, an output device 917, a storage device 919, a drive 921, and a connection port 923. And a communication device 925.
- the CPU 901 functions as an arithmetic processing unit and a control unit, and controls all or a part of the operation in the information processing apparatus 900 according to various programs recorded in the ROM 903, the RAM 905, the storage apparatus 919, or the removable recording medium 927.
- the ROM 903 stores programs used by the CPU 901, calculation parameters, and the like.
- the RAM 905 primarily stores programs used by the CPU 901, parameters that change as appropriate during execution of the programs, and the like. These are connected to each other by a host bus 907 constituted by an internal bus such as a CPU bus. Note that the FB-NC filter 101a and the loop cancellers 109a and 109b described above with reference to FIG. 6 can be realized by the CPU 901, for example.
- the host bus 907 is connected to an external bus 911 such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge 909.
- an input device 915, an output device 917, a storage device 919, a drive 921, a connection port 923, and a communication device 925 are connected to the external bus 911 via an interface 913.
- the input device 915 is an operation means operated by the user, such as a mouse, a keyboard, a touch panel, a button, a switch, a lever, and a pedal. Further, the input device 915 may be, for example, remote control means (so-called remote control) using infrared rays or other radio waves, or an external connection device such as a mobile phone or a PDA corresponding to the operation of the information processing device 900. 929 may be used. Furthermore, the input device 915 includes an input control circuit that generates an input signal based on information input by a user using the above-described operation means and outputs the input signal to the CPU 901, for example. A user of the information processing apparatus 900 can input various data and instruct a processing operation to the information processing apparatus 900 by operating the input device 915.
- the output device 917 is a device that can notify the user of the acquired information visually or audibly. Examples of such devices include CRT display devices, liquid crystal display devices, plasma display devices, EL display devices, display devices such as lamps, audio output devices such as speakers and headphones, printer devices, and the like.
- the output device 917 outputs results obtained by various processes performed by the information processing apparatus 900. Specifically, the display device displays results obtained by various processes performed by the information processing device 900 as text or images.
- the audio output device converts an audio signal composed of reproduced audio data, acoustic data, and the like into an analog signal and outputs the analog signal. Note that the acoustic devices 11a and 11b described above with reference to FIG. 6 can be realized by the output device 917, for example.
- the storage device 919 is a data storage device configured as an example of a storage unit of the information processing device 900.
- the storage device 919 includes, for example, a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device.
- the storage device 919 stores programs executed by the CPU 901 and various data.
- the drive 921 is a reader / writer for a recording medium, and is built in or externally attached to the information processing apparatus 900.
- the drive 921 reads information recorded on a removable recording medium 927 such as a mounted magnetic disk, optical disk, magneto-optical disk, or semiconductor memory, and outputs the information to the RAM 905.
- the drive 921 can also write a record to a removable recording medium 927 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory that is mounted.
- the removable recording medium 927 is, for example, a DVD medium, an HD-DVD medium, a Blu-ray (registered trademark) medium, or the like.
- the removable recording medium 927 may be a compact flash (registered trademark) (CF: CompactFlash), a flash memory, an SD memory card (Secure Digital memory card), or the like. Further, the removable recording medium 927 may be, for example, an IC card (Integrated Circuit card) on which a non-contact IC chip is mounted, an electronic device, or the like.
- CF CompactFlash
- SD memory card Secure Digital memory card
- the connection port 923 is a port for directly connecting to the information processing apparatus 900.
- Examples of the connection port 923 include a USB (Universal Serial Bus) port, an IEEE 1394 port, a SCSI (Small Computer System Interface) port, and the like.
- As another example of the connection port 923 there are an RS-232C port, an optical audio terminal, an HDMI (registered trademark) (High-Definition Multimedia Interface) port, and the like.
- the communication device 925 is a communication interface configured with, for example, a communication device for connecting to a communication network (network) 931.
- the communication device 925 is, for example, a communication card for wired or wireless LAN (Local Area Network), Bluetooth (registered trademark), or WUSB (Wireless USB).
- the communication device 925 may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), a modem for various communication, or the like.
- the communication device 925 can transmit and receive signals and the like according to a predetermined protocol such as TCP / IP, for example, with the Internet or other communication devices.
- the communication network 931 connected to the communication device 925 is configured by a wired or wireless network, and may be, for example, the Internet, a home LAN, infrared communication, radio wave communication, satellite communication, or the like. .
- each component described above may be configured using a general-purpose member, or may be configured by hardware specialized for the function of each component. Therefore, it is possible to change the hardware configuration to be used as appropriate according to the technical level at the time of carrying out this embodiment.
- FIG. 25 various configurations corresponding to the information processing apparatus 900 configuring the noise reduction system 1 according to the present embodiment are naturally provided.
- a computer program for realizing each function of the information processing apparatus 900 constituting the noise reduction system 1 according to the present embodiment as described above can be produced and mounted on a personal computer or the like.
- a computer-readable recording medium storing such a computer program can be provided.
- the recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like.
- the above computer program may be distributed via a network, for example, without using a recording medium.
- the number of computers that execute the computer program is not particularly limited.
- the computer program may be executed by a plurality of computers (for example, a plurality of servers) in cooperation with each other.
- the noise reduction system generates the first noise reduction signal for driving the first acoustic device that outputs the first sound for reducing the noise.
- the noise reduction system according to the present embodiment is different from the first acoustic device that propagates from the first acoustic device via the first propagation path by the predetermined sound collecting unit.
- the first noise reduction signal is generated based on a cancellation signal based on a second noise reduction signal for driving the second acoustic device.
- the noise reduction system according to the present embodiment can improve the independence of each of a plurality of feedback systems. For this reason, it is possible to suppress the influence caused by the formation of the unexpected 8-shaped closed loop, which may occur in an environment where the user listens to the sound output to the released space, and to reduce noise in a more preferable manner. It becomes possible to reduce the influence of.
- a generator that generates a first noise reduction signal for driving a first acoustic device that outputs a first sound for reducing noise; The first sound propagating from the first acoustic device via the first propagation path and the second propagation from a second acoustic device different from the first acoustic device by a predetermined sound collecting unit An acquisition unit for acquiring a sound collection result of the sound including the second sound propagating through the path; With The generation unit generates the first noise reduction signal based on the sound collection result and a cancellation signal based on a second noise reduction signal for driving the second acoustic device. Signal processing device.
- the signal processing device further including a signal processing unit that generates the cancellation signal by performing filtering processing based on characteristics of the second propagation path on the second noise reduction signal. .
- the first acoustic device and the sound collection unit, and the second acoustic device are held in the vicinity of different ears of the listener's right ear and left ear,
- the signal processing unit is configured to control the second propagation path according to a characteristic of the second propagation path based on a positional relationship between the sound collection unit, the second acoustic device, and the listener's head. Applying the filtering to the noise reduction signal;
- the signal processing apparatus according to (2).
- a detection unit that detects a positional relationship between the sound collection unit, the second acoustic device, and the head of the listener;
- the signal processing unit generates the cancel signal by performing a filtering process based on a characteristic of the second propagation path according to the detection result of the positional relationship with respect to the second noise reduction signal.
- the signal processing device according to (3).
- the signal processing unit selects the filter according to the characteristic of the second propagation path according to the detection result of the positional relationship from among a plurality of filters having different characteristics from each other, and the first processor based on the selected filter
- the signal processing device according to (4), wherein the canceling signal is generated by performing the filtering process on the noise reduction signal 2.
- the detection unit detects the positional relationship based on a light reception result by a predetermined light receiving element of light projected from a predetermined light source and reflected by the head of the listener, (4) or (5) A signal processing device according to 1.
- the detection unit is based on the sound collection result of the ultrasonic wave output from the predetermined acoustic device by the predetermined sound collection unit, the head of the listener located in an environment where the ultrasonic wave propagates, and the sound collection
- the signal processing apparatus according to (4) or (5), wherein the positional relationship between the unit and the second acoustic device is detected.
- the detection unit detects the positional relationship based on a delay time until sound output from a predetermined acoustic device is collected by a predetermined sound collection unit attached to the listener's head, The signal processing device according to (4) or (5).
- the first acoustic device, the second acoustic device, and the sound collecting unit are held so as to have a predetermined positional relationship with respect to a headrest that supports the listener's head, (3) 10.
- (11) The signal processing apparatus according to (10), wherein the first acoustic device and the second acoustic device are provided in the headrest.
- (12) The signal processing device according to (10) or (11), wherein the headrest is provided on a seat installed in a vehicle.
- the filtering process includes a noise reduction process based on a feedback method.
- the signal processing apparatus according to any one of (2) to (13), wherein the filtering process is a process of controlling at least one of a gain and a phase of the second noise reduction signal.
- the filtering process is a process of controlling at least one of a gain and a phase of the second noise reduction signal.
- the first sound propagating via the other acquisition unit for acquiring the sound collection result of the sound including Another generation unit that generates the second noise reduction signal based on the sound collection result acquired by the other acquisition unit and another cancellation signal based on the first noise reduction signal;
- the signal processing apparatus according to any one of (1) to (14), comprising: (16) The signal processing apparatus according to any one of (1) to (15), including at least one of the first acoustic device, the second acoustic device, and the sound collection unit.
- Processor Generating a first noise reduction signal for driving a first acoustic device that outputs a first sound for reducing noise;
- the first sound propagating from the first acoustic device via the first propagation path and the second propagation from a second acoustic device different from the first acoustic device by a predetermined sound collecting unit Obtaining a sound collection result of the sound including the second sound propagating through the path;
- the first noise reduction signal is generated based on the sound collection result and a cancellation signal based on a second noise reduction signal for driving the second acoustic device.
Landscapes
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Physics & Mathematics (AREA)
- Multimedia (AREA)
- Mechanical Engineering (AREA)
- Transportation (AREA)
- Aviation & Aerospace Engineering (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Signal Processing (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
- Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
Abstract
Description
1.概略構成
2.ノイズ低減処理に関する検討
3.技術的特徴
3.1.機能構成
3.2.信号処理
3.3.音響デバイス及び集音部の設置位置
4.変形例
4.1.変形例1:ループキャンセラの特性を適応的に制御する場合の一例
4.2.変形例2:フィルタの切り替えに係る制御の一例
4.3.変形例3:フィードバックの系が3つ以上の場合の一例
5.ハードウェア構成
6.むすび
まず、図1及び図2を参照して、本開示の一実施形態に係るノイズ低減システムの概略的な構成の一例について説明する。図1及び図2は、本実施形態に係るノイズ低減システムの概略的な構成の一例について説明するための説明図である。
続いて、図3~図5を参照して、FB方式に基づくノイズ低減処理の概要について説明したうえで、本実施形態に係るノイズ低減システム1の課題について整理する。図3~図5は、FB方式に基づくノイズ低減処理の概要について説明するための説明図である。
続いて、本実施形態に係るノイズ低減システム1の技術的特徴について説明する。
まず、図6を参照して、本実施形態に係るノイズ低減システム1の機能構成の一例について説明する。図6は、本実施形態に係るノイズ低減システム1の機能構成の一例を示したブロック図である。
続いて、図7を参照して、本実施形態に係るノイズ低減システム1の信号処理の一例について説明する。図7は、本実施形態に係るノイズ低減システム1の信号処理に着目したブロック図の一例を示している。なお、図7に示す例では、本実施形態に係るノイズ低減システム1における信号処理の特徴をよりわかりやすくするために、図6に示した、パワーアンプ103a及び103bや、マイクアンプ105a及び105bについては、図示を省略している。
続いて、音響デバイス11及び集音部13の設置位置の条件に付いて、より詳しく説明する。前述したように、本実施形態に係るノイズ低減システム1では、FB方式に基づくノイズ低減処理により雑音の影響を低減する。そのため、ノイズ低減の効果が集音部13の近傍に制限され、かつ、当該集音部13は、音響デバイス11の近傍に設置されることがより望ましい。即ち、本実施形態に係るノイズ低減システム1では、音響デバイス11及び集音部13のそれぞれが、聴取者の耳(鼓膜)の近傍に支持される構成とすることが望ましい。
続いて、本実施形態に係るノイズ低減システム1の変形例について説明する。
まず、変形例1として、音響デバイス11a及び11bそれぞれから出力される音響が伝搬する環境の特性の変化に応じて、前述したループキャンセラ109a及び109bの特性を適応的に制御する場合の一例について説明する。
例えば、図13は、変形例1に係るノイズ低減システムの概略的な構成の一例について説明するための説明図である。なお、本説明では、図13に示すノイズ低減システムを、前述したノイズ低減システム1と区別するために、「ノイズ低減システム2」と称する場合がある。
次いで、図17を参照して、変形例1に係るノイズ低減システム3の信号処理の一例について説明する。図17は、変形例1に係るノイズ低減システム3の信号処理に着目したブロック図の一例を示している。なお、図17に示す例では、変形例1に係るノイズ低減システム3における信号処理の特徴をよりわかりやすくするために、図14に示した、パワーアンプ303a及び303bや、マイクアンプ305a及び305bについては、図示を省略している。
次いで、図18~図21を参照して、ユーザU11の頭部位置を推定するための構成及び方法の一例について説明する。図18~図21は、ユーザU11の頭部位置を推定するための構成及び方法の一例について説明するための説明図である。
続いて、変形例2として、図14を参照して説明したノイズ低減システム3において、FB-NCフィルタやループキャンセラを切り替える場合における制御の一例について説明する。
続いて、変形例3として、ノイズ低減のためのフィードバックの系を3つ以上設ける場合におけるノイズ低減システムの構成の一例について説明する。前述では、主に、ユーザの左耳近傍においてノイズを低減するためのフィードバックの系と、右耳近傍においてノイズを低減するためのフィードバックの系とが設けられている場合の一例について説明した。一方で、ノイズ低減のためのフィードバックの系の数は、前述した2つの例に限らず、3つ以上設けられていてもよい。例えば、図24は、変形例3に係るノイズ低減システムについて説明するための説明図であり、当該ノイズ低減システムの信号処理に着目したブロック図である。なお、以降の説明では、図24に示すノイズ低減システムを、前述した実施形態及び変形例に係るノイズ低減システムと区別するために、「ノイズ低減システム4」と称する場合がある。なお、本説明においては、「フィードバックの系」と記載した場合には、ノイズ低減処理のためのフィードバックの閉ループを形成する系を示すものとする。
次に、図25を参照しながら、本実施形態に係るノイズ低減システム1を構成する情報処理装置900のハードウェア構成について、詳細に説明する。図25は、本開示の一実施形態に係るノイズ低減システム1を構成する情報処理装置900のハードウェア構成の一構成例を示す機能ブロック図である。
以上説明したように、本実施形態に係るノイズ低減システムは、ノイズを低減するための第1の音響を出力する第1の音響デバイスを駆動するための第1のノイズ低減信号を生成する生成部(即ち、NC-FBフィルタ)を含む。また、本実施形態に係るノイズ低減システムは、所定の集音部による、第1の音響デバイスから第1の伝搬経路を介して伝搬する第1の音響と、当該第1の音響デバイスとは異なる第2の音響デバイスから第2の伝搬経路を介して伝搬する第2の音響と、を含む音響の集音結果を取得する、そして、当該生成部は、上記集音部による集音結果と、第2の音響デバイスを駆動するための第2のノイズ低減信号に基づくキャンセル信号と、に基づき、上記第1のノイズ低減信号を生成する。このような構成により、本実施形態に係るノイズ低減システムは、複数のフィードバックの系それぞれの独立性を向上させることが可能となる。そのため、解放された空間に出力された音響をユーザが聴取するような環境下において生じ得る、本来想定していない8の字型の閉ループの形成に伴う影響を抑制し、より好適な態様で雑音の影響を低減することが可能となる。
(1)
ノイズを低減するための第1の音響を出力する第1の音響デバイスを駆動するための第1のノイズ低減信号を生成する生成部と、
所定の集音部による、前記第1の音響デバイスから第1の伝搬経路を介して伝搬する前記第1の音響と、当該第1の音響デバイスとは異なる第2の音響デバイスから第2の伝搬経路を介して伝搬する第2の音響と、を含む音響の集音結果を取得する取得部と、
を備え、
前記生成部は、前記集音結果と、前記第2の音響デバイスを駆動するための第2のノイズ低減信号に基づくキャンセル信号と、に基づき、前記第1のノイズ低減信号を生成する、
信号処理装置。
(2)
前記第2のノイズ低減信号に対して、前記第2の伝搬経路の特性に基づくフィルタリング処理を施すことで、前記キャンセル信号を生成する信号処理部を備える、前記(1)に記載の信号処理装置。
(3)
前記第1の音響デバイス及び前記集音部と、前記第2の音響デバイスとは、聴取者の右耳及び左耳のうち互いに異なる耳の近傍に保持され、
前記信号処理部は、前記集音部と、前記第2の音響デバイスと、前記聴取者の頭部との間の位置関係に基づく前記第2の伝搬経路の特性に応じて、前記第2のノイズ低減信号に対して前記フィルタリング処理を施す、
前記(2)に記載の信号処理装置。
(4)
前記集音部と、前記第2の音響デバイスと、前記聴取者の頭部との間の位置関係を検出する検出部を備え、
前記信号処理部は、前記第2のノイズ低減信号に対して、前記位置関係の検出結果に応じた前記第2の伝搬経路の特性に基づくフィルタリング処理を施すことで、前記キャンセル信号を生成する、
前記(3)に記載の信号処理装置。
(5)
前記信号処理部は、互いに特性の異なる複数のフィルタのうち、前記位置関係の検出結果に応じた前記第2の伝搬経路の特性に応じた前記フィルタを選択し、選択した当該フィルタに基づき前記第2のノイズ低減信号に対して前記フィルタリング処理を施すことで、前記キャンセル信号を生成する、前記(4)に記載の信号処理装置。
(6)
前記検出部は、所定の光源から投光されて前記聴取者の頭部で反射した光の、所定の受光素子による受光結果に基づき、前記位置関係を検出する、前記(4)または(5)に記載の信号処理装置。
(7)
前記検出部は、所定の撮像部により撮像された前記聴取者の頭部の画像に基づき、前記位置関係を検出する、前記(4)または(5)に記載の信号処理装置。
(8)
前記検出部は、所定の音響デバイスから出力された超音波の、所定の集音部による集音結果に基づき、当該超音波が伝搬する環境に位置する前記聴取者の頭部と、前記集音部と、前記第2の音響デバイスとの間の前記位置関係を検出する、前記(4)または(5)に記載の信号処理装置。
(9)
前記検出部は、所定の音響デバイスから出力された音響が、前記聴取者の頭部に装着された所定の集音部により集音されるまでの遅延時間に基づき、前記位置関係を検出する、前記(4)または(5)に記載の信号処理装置。
(10)
前記第1の音響デバイス、前記第2の音響デバイス、及び前記集音部は、前記聴取者の頭部を支持するヘッドレストに対して所定の位置関係となるように保持される、前記(3)~(9)のいずれか一項に記載の信号処理装置。
(11)
前記第1の音響デバイス及び前記第2の音響デバイスは、前記ヘッドレストに設けられている、前記(10)に記載の信号処理装置。
(12)
前記ヘッドレストは、車両内に設置されたシートに設けられている、前記(10)または(11)に記載の信号処理装置。
(13)
前記フィルタリング処理は、フィードバック方式に基づくノイズ低減処理を含む、前記(2)~(12)のいずれか一項に記載の信号処理装置。
(14)
前記フィルタリング処理は、前記第2のノイズ低減信号のゲイン及び位相のうち少なくともいずれかを制御する処理である、前記(2)~(13)のいずれか一項に記載の信号処理装置。
(15)
前記集音部とは異なる他の集音部による、前記第2の音響デバイスから第3の伝搬経路を介して伝搬する前記第2の音響と、前記第1の音響デバイスから第4の伝搬経路を介して伝搬する前記第1の音響と、を含む音響の集音結果を取得する他の取得部と、
前記他の取得部により取得された当該集音結果と、前記第1のノイズ低減信号に基づく他のキャンセル信号と、に基づき、前記第2のノイズ低減信号を生成する他の生成部と、
を備える、前記(1)~(14)のいずれか一項に記載の信号処理装置。
(16)
前記第1の音響デバイス、前記第2の音響デバイス、及び前記集音部のうち、少なくともいずれかを含む、前記(1)~(15)のいずれか一項に記載の信号処理装置。
(17)
プロセッサが、
ノイズを低減するための第1の音響を出力する第1の音響デバイスを駆動するための第1のノイズ低減信号を生成することと、
所定の集音部による、前記第1の音響デバイスから第1の伝搬経路を介して伝搬する前記第1の音響と、当該第1の音響デバイスとは異なる第2の音響デバイスから第2の伝搬経路を介して伝搬する第2の音響と、を含む音響の集音結果を取得することと、
含み、
前記第1のノイズ低減信号は、前記集音結果と、前記第2の音響デバイスを駆動するための第2のノイズ低減信号に基づくキャンセル信号と、に基づき生成される、
信号処理方法。
(18)
コンピュータに、
ノイズを低減するための第1の音響を出力する第1の音響デバイスを駆動するための第1のノイズ低減信号を生成することと、
所定の集音部による、前記第1の音響デバイスから第1の伝搬経路を介して伝搬する前記第1の音響と、当該第1の音響デバイスとは異なる第2の音響デバイスから第2の伝搬経路を介して伝搬する第2の音響と、を含む音響の集音結果を取得することと、
実行させ、
前記第1のノイズ低減信号は、前記集音結果と、前記第2の音響デバイスを駆動するための第2のノイズ低減信号に基づくキャンセル信号と、に基づき生成される、
プログラム。
11a、11b 音響デバイス
13a、13b 集音部
101a、101b NC-FBフィルタ
103a、103b パワーアンプ
105a、105b マイクアンプ
107a、107b 減算器
109a、109b ループキャンセラ
Claims (18)
- ノイズを低減するための第1の音響を出力する第1の音響デバイスを駆動するための第1のノイズ低減信号を生成する生成部と、
所定の集音部による、前記第1の音響デバイスから第1の伝搬経路を介して伝搬する前記第1の音響と、当該第1の音響デバイスとは異なる第2の音響デバイスから第2の伝搬経路を介して伝搬する第2の音響と、を含む音響の集音結果を取得する取得部と、
を備え、
前記生成部は、前記集音結果と、前記第2の音響デバイスを駆動するための第2のノイズ低減信号に基づくキャンセル信号と、に基づき、前記第1のノイズ低減信号を生成する、
信号処理装置。 - 前記第2のノイズ低減信号に対して、前記第2の伝搬経路の特性に基づくフィルタリング処理を施すことで、前記キャンセル信号を生成する信号処理部を備える、請求項1に記載の信号処理装置。
- 前記第1の音響デバイス及び前記集音部と、前記第2の音響デバイスとは、聴取者の右耳及び左耳のうち互いに異なる耳の近傍に保持され、
前記信号処理部は、前記集音部と、前記第2の音響デバイスと、前記聴取者の頭部との間の位置関係に基づく前記第2の伝搬経路の特性に応じて、前記第2のノイズ低減信号に対して前記フィルタリング処理を施す、
請求項2に記載の信号処理装置。 - 前記集音部と、前記第2の音響デバイスと、前記聴取者の頭部との間の位置関係を検出する検出部を備え、
前記信号処理部は、前記第2のノイズ低減信号に対して、前記位置関係の検出結果に応じた前記第2の伝搬経路の特性に基づくフィルタリング処理を施すことで、前記キャンセル信号を生成する、
請求項3に記載の信号処理装置。 - 前記信号処理部は、互いに特性の異なる複数のフィルタのうち、前記位置関係の検出結果に応じた前記第2の伝搬経路の特性に応じた前記フィルタを選択し、選択した当該フィルタに基づき前記第2のノイズ低減信号に対して前記フィルタリング処理を施すことで、前記キャンセル信号を生成する、請求項4に記載の信号処理装置。
- 前記検出部は、所定の光源から投光されて前記聴取者の頭部で反射した光の、所定の受光素子による受光結果に基づき、前記位置関係を検出する、請求項4に記載の信号処理装置。
- 前記検出部は、所定の撮像部により撮像された前記聴取者の頭部の画像に基づき、前記位置関係を検出する、請求項4に記載の信号処理装置。
- 前記検出部は、所定の音響デバイスから出力された超音波の、所定の集音部による集音結果に基づき、当該超音波が伝搬する環境に位置する前記聴取者の頭部と、前記集音部と、前記第2の音響デバイスとの間の前記位置関係を検出する、請求項4に記載の信号処理装置。
- 前記検出部は、所定の音響デバイスから出力された音響が、前記聴取者の頭部に装着された所定の集音部により集音されるまでの遅延時間に基づき、前記位置関係を検出する、請求項4に記載の信号処理装置。
- 前記第1の音響デバイス、前記第2の音響デバイス、及び前記集音部は、前記聴取者の頭部を支持するヘッドレストに対して所定の位置関係となるように保持される、請求項3に記載の信号処理装置。
- 前記第1の音響デバイス及び前記第2の音響デバイスは、前記ヘッドレストに設けられている、請求項10に記載の信号処理装置。
- 前記ヘッドレストは、車両内に設置されたシートに設けられている、請求項10に記載の信号処理装置。
- 前記フィルタリング処理は、フィードバック方式に基づくノイズ低減処理を含む、請求項2に記載の信号処理装置。
- 前記フィルタリング処理は、前記第2のノイズ低減信号のゲイン及び位相のうち少なくともいずれかを制御する処理である、請求項2に記載の信号処理装置。
- 前記集音部とは異なる他の集音部による、前記第2の音響デバイスから第3の伝搬経路を介して伝搬する前記第2の音響と、前記第1の音響デバイスから第4の伝搬経路を介して伝搬する前記第1の音響と、を含む音響の集音結果を取得する他の取得部と、
前記他の取得部により取得された当該集音結果と、前記第1のノイズ低減信号に基づく他のキャンセル信号と、に基づき、前記第2のノイズ低減信号を生成する他の生成部と、
を備える、請求項1に記載の信号処理装置。 - 前記第1の音響デバイス、前記第2の音響デバイス、及び前記集音部のうち、少なくともいずれかを含む、請求項1に記載の信号処理装置。
- プロセッサが、
ノイズを低減するための第1の音響を出力する第1の音響デバイスを駆動するための第1のノイズ低減信号を生成することと、
所定の集音部による、前記第1の音響デバイスから第1の伝搬経路を介して伝搬する前記第1の音響と、当該第1の音響デバイスとは異なる第2の音響デバイスから第2の伝搬経路を介して伝搬する第2の音響と、を含む音響の集音結果を取得することと、
含み、
前記第1のノイズ低減信号は、前記集音結果と、前記第2の音響デバイスを駆動するための第2のノイズ低減信号に基づくキャンセル信号と、に基づき生成される、
信号処理方法。 - コンピュータに、
ノイズを低減するための第1の音響を出力する第1の音響デバイスを駆動するための第1のノイズ低減信号を生成することと、
所定の集音部による、前記第1の音響デバイスから第1の伝搬経路を介して伝搬する前記第1の音響と、当該第1の音響デバイスとは異なる第2の音響デバイスから第2の伝搬経路を介して伝搬する第2の音響と、を含む音響の集音結果を取得することと、
実行させ、
前記第1のノイズ低減信号は、前記集音結果と、前記第2の音響デバイスを駆動するための第2のノイズ低減信号に基づくキャンセル信号と、に基づき生成される、
プログラム。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP17778827.0A EP3441965A4 (en) | 2016-04-05 | 2017-01-24 | SIGNAL PROCESSING DEVICE, SIGNAL PROCESSING METHOD, AND PROGRAM |
JP2018510236A JPWO2017175448A1 (ja) | 2016-04-05 | 2017-01-24 | 信号処理装置、信号処理方法、及びプログラム |
CN201780021206.4A CN109074799A (zh) | 2016-04-05 | 2017-01-24 | 信号处理设备、信号处理方法及程序 |
US16/088,892 US20190251948A1 (en) | 2016-04-05 | 2017-01-24 | Signal processing device, signal processing method, and program |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016076100 | 2016-04-05 | ||
JP2016-076100 | 2016-04-05 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017175448A1 true WO2017175448A1 (ja) | 2017-10-12 |
Family
ID=60000366
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2017/002219 WO2017175448A1 (ja) | 2016-04-05 | 2017-01-24 | 信号処理装置、信号処理方法、及びプログラム |
Country Status (5)
Country | Link |
---|---|
US (1) | US20190251948A1 (ja) |
EP (1) | EP3441965A4 (ja) |
JP (1) | JPWO2017175448A1 (ja) |
CN (1) | CN109074799A (ja) |
WO (1) | WO2017175448A1 (ja) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108710106A (zh) * | 2018-05-15 | 2018-10-26 | 中国科学院声学研究所 | 一种基于红外定位的有源头枕装置 |
WO2019106748A1 (ja) * | 2017-11-29 | 2019-06-06 | 三菱電機株式会社 | 音響信号制御装置及び方法、並びにプログラム及び記録媒体 |
JP2020189583A (ja) * | 2019-05-22 | 2020-11-26 | アルパイン株式会社 | 能動型騒音制御システム |
WO2021157614A1 (ja) * | 2020-02-05 | 2021-08-12 | 豊通ケミプラス株式会社 | 騒音低減装置および騒音低減方法 |
JPWO2020208667A1 (ja) * | 2019-04-08 | 2021-09-13 | 三菱電機株式会社 | 音声出力制御装置及び音声出力制御方法 |
US11257476B2 (en) | 2018-03-16 | 2022-02-22 | Sony Corporation | Signal processing apparatus and signal processing method |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109983782B (zh) | 2016-09-30 | 2021-06-01 | 雅马哈株式会社 | 会话辅助装置及会话辅助方法 |
DE102018120503A1 (de) * | 2018-08-22 | 2020-02-27 | recalm GmbH | Geräuschreduzierungssystem und Verfahren zur aktiven Kompensation von Störgeräuschen |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5133017A (en) * | 1990-04-09 | 1992-07-21 | Active Noise And Vibration Technologies, Inc. | Noise suppression system |
JP2004165994A (ja) * | 2002-11-13 | 2004-06-10 | Nippon Telegr & Teleph Corp <Ntt> | 反響消去装置、反響消去方法および反響消去プログラム |
JP2006262338A (ja) * | 2005-03-18 | 2006-09-28 | Yamaha Corp | ハウリングキャンセラ及びこれを備えた拡声装置 |
JP2007160974A (ja) * | 2005-12-09 | 2007-06-28 | Olympus Corp | 車載用情報再生装置 |
JP4882773B2 (ja) | 2007-02-05 | 2012-02-22 | ソニー株式会社 | 信号処理装置、信号処理方法 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5216722A (en) * | 1991-11-15 | 1993-06-01 | Nelson Industries, Inc. | Multi-channel active attenuation system with error signal inputs |
GB2360900B (en) * | 2000-03-30 | 2004-01-28 | Roke Manor Research | Apparatus and method for reducing noise |
JP4485792B2 (ja) * | 2001-10-03 | 2010-06-23 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | 不要なラウドスピーカ信号をキャンセルする方法 |
EP1909262A4 (en) * | 2005-07-27 | 2013-07-31 | Panasonic Corp | ACTIVE VIBRATION / NOISE CONTROLLER |
-
2017
- 2017-01-24 US US16/088,892 patent/US20190251948A1/en not_active Abandoned
- 2017-01-24 CN CN201780021206.4A patent/CN109074799A/zh not_active Withdrawn
- 2017-01-24 EP EP17778827.0A patent/EP3441965A4/en not_active Withdrawn
- 2017-01-24 JP JP2018510236A patent/JPWO2017175448A1/ja active Pending
- 2017-01-24 WO PCT/JP2017/002219 patent/WO2017175448A1/ja active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5133017A (en) * | 1990-04-09 | 1992-07-21 | Active Noise And Vibration Technologies, Inc. | Noise suppression system |
JP2004165994A (ja) * | 2002-11-13 | 2004-06-10 | Nippon Telegr & Teleph Corp <Ntt> | 反響消去装置、反響消去方法および反響消去プログラム |
JP2006262338A (ja) * | 2005-03-18 | 2006-09-28 | Yamaha Corp | ハウリングキャンセラ及びこれを備えた拡声装置 |
JP2007160974A (ja) * | 2005-12-09 | 2007-06-28 | Olympus Corp | 車載用情報再生装置 |
JP4882773B2 (ja) | 2007-02-05 | 2012-02-22 | ソニー株式会社 | 信号処理装置、信号処理方法 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3441965A4 |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2019106748A1 (ja) * | 2017-11-29 | 2019-06-06 | 三菱電機株式会社 | 音響信号制御装置及び方法、並びにプログラム及び記録媒体 |
CN111373471A (zh) * | 2017-11-29 | 2020-07-03 | 三菱电机株式会社 | 声响信号控制装置及方法、以及程序及记录介质 |
US11153683B2 (en) | 2017-11-29 | 2021-10-19 | Mitsubishi Electric Corporation | Sound signal control device and method, and recording medium |
CN111373471B (zh) * | 2017-11-29 | 2023-11-21 | 三菱电机株式会社 | 声响信号控制装置及方法、以及记录介质 |
US11257476B2 (en) | 2018-03-16 | 2022-02-22 | Sony Corporation | Signal processing apparatus and signal processing method |
CN108710106A (zh) * | 2018-05-15 | 2018-10-26 | 中国科学院声学研究所 | 一种基于红外定位的有源头枕装置 |
CN108710106B (zh) * | 2018-05-15 | 2021-04-09 | 中国科学院声学研究所 | 一种基于红外定位的有源头枕装置 |
JPWO2020208667A1 (ja) * | 2019-04-08 | 2021-09-13 | 三菱電機株式会社 | 音声出力制御装置及び音声出力制御方法 |
JP2020189583A (ja) * | 2019-05-22 | 2020-11-26 | アルパイン株式会社 | 能動型騒音制御システム |
JP7262899B2 (ja) | 2019-05-22 | 2023-04-24 | アルパイン株式会社 | 能動型騒音制御システム |
WO2021157614A1 (ja) * | 2020-02-05 | 2021-08-12 | 豊通ケミプラス株式会社 | 騒音低減装置および騒音低減方法 |
Also Published As
Publication number | Publication date |
---|---|
US20190251948A1 (en) | 2019-08-15 |
EP3441965A1 (en) | 2019-02-13 |
CN109074799A (zh) | 2018-12-21 |
EP3441965A4 (en) | 2019-05-22 |
JPWO2017175448A1 (ja) | 2019-02-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2017175448A1 (ja) | 信号処理装置、信号処理方法、及びプログラム | |
JP6150988B2 (ja) | 特に「ハンズフリー」電話システム用の、小数遅延フィルタリングにより音声信号のノイズ除去を行うための手段を含むオーディオ装置 | |
US9031256B2 (en) | Systems, methods, apparatus, and computer-readable media for orientation-sensitive recording control | |
US8290177B2 (en) | Sound zoom method, medium, and apparatus | |
JP4286637B2 (ja) | マイクロホン装置および再生装置 | |
JP5026495B2 (ja) | 音声信号補償を用いるアクティブノイズコントロールのためのシステム | |
JP4767166B2 (ja) | ハウリング抑圧装置、プログラム、集積回路、およびハウリング抑圧方法 | |
US9516411B2 (en) | Signal-separation system using a directional microphone array and method for providing same | |
US8855341B2 (en) | Systems, methods, apparatus, and computer-readable media for head tracking based on recorded sound signals | |
US8229129B2 (en) | Method, medium, and apparatus for extracting target sound from mixed sound | |
CN111373471B (zh) | 声响信号控制装置及方法、以及记录介质 | |
US20160189728A1 (en) | Voice Signal Processing Method and Apparatus | |
JP2016541222A (ja) | フィードバック検出のためのシステムおよび方法 | |
JP7352291B2 (ja) | 音響装置 | |
AU2016247284B2 (en) | Calibration of acoustic echo cancelation for multi-channel sound in dynamic acoustic environments | |
US10878796B2 (en) | Mobile platform based active noise cancellation (ANC) | |
JP5762479B2 (ja) | 音声スイッチ装置、音声スイッチ方法、及びそのプログラム | |
Tashev | Recent advances in human-machine interfaces for gaming and entertainment | |
JP6355049B2 (ja) | 音響信号処理方法、及び音響信号処理装置 | |
JPWO2018066384A1 (ja) | 信号処理装置および方法、並びにプログラム | |
CN109982197B (zh) | 区域再生方法、计算机可读取的记录介质及区域再生系统 | |
CN118158590A (zh) | 开放式可穿戴声学设备及主动降噪方法 | |
CN118158589A (zh) | 开放式可穿戴声学设备及主动降噪方法 | |
CN118158588A (zh) | 开放式可穿戴声学设备及其主动降噪方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 2018510236 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2017778827 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2017778827 Country of ref document: EP Effective date: 20181105 |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 17778827 Country of ref document: EP Kind code of ref document: A1 |