JP2007052373A - Acoustic transmission apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acoustic transmission apparatus, capable of determining a coming direction of sound collected by two sound collecting means and transmitting the sound. <P>SOLUTION: The apparatus comprises; two sound collecting means having directivity, capable of collecting an acoustic signal; a coming direction determining means for determining the coming direction of the acoustic signal at least in four directions of nearly the front, back, right and left of a person, from magnitude relation of arrival phase difference and/or arrival level difference of each collected sound signal collected by each sound collecting means; a filter means for determining whether a predetermined acoustic signal is included in each collected signal which is collected by each sound collecting means; and an indicating means for indicating the coming direction of the acoustic signal which is determined by the coming direction determining means to the person, when it is determined by the filter means that a predetermined acoustic signal is included at least in any of the collected means. Directions of directivity of the sound collecting means are a nearly oblique left rear direction and a nearly oblique right rear direction of the person, respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sound transmission device that informs a person of the presence of sound along with its direction of arrival.

  For example, a hearing-impaired person has difficulty recognizing or distinguishing sounds in daily life, so he / she must recognize his / her surrounding environment by relying on sensory organs other than hearing (for example, eyes). In order to eliminate the inconvenience of such hearing-impaired persons, etc., sound is collected by a microphone, and information other than vibration, light, and other sounds is generated based on the collected acoustic signals, and this is used for hearing-impaired persons, etc. A device to be presented (acoustic transmission device) has been proposed (see, for example, Non-Patent Documents 1, 2, 3, and 4).

  Each of these devices employs a structure in which a microphone is installed near a sound source that is desired to be notified and generates vibration or light when a sound volume exceeding a threshold is generated. In addition to these, an acoustic transmission device has also been developed in which sounds to be notified are registered in advance, the desired sound matched with the input sound is recognized, and the recognition result is presented by vibration or text. (For example, refer nonpatent literatures 5 and 6.).

  Furthermore, an acoustic transmission device has also been developed that transmits vibrations corresponding to this sound to a hearing impaired person when the collected sound is compared with the sound recorded and registered in advance and determined to be the same sound (for example, (See Patent Document 1).

  In these conventional techniques, it is impossible to detect the direction of arrival of a desired sound. That is, it is impossible to determine the sound coming from an arbitrary direction and convey the direction of arrival to a hearing impaired person or the like.

As a solution to this problem, in addition to the above-mentioned conventional technology, as used in the microphone array technology, etc., the arrival time difference between channels is extracted using three or more channels of microphones, so that the desired sound arrival direction is Thereafter, a method of discriminating between left and right is conceivable (for example, see Non-Patent Document 7).
Alert Master [Search August 9, 2005], Internet <URL: http://www.jiritsu.com/> Assist Co., Ltd. System Five [Search August 9, 2005], Internet <URL: http: //www3.ocn.nejp/~assisthp/> Rion Corporation News Lamp [Search August 9, 2005], Internet <URL: http://www.rion.co.jp/> Tokyo Shintomo Co., Ltd.'s sill watch [search August 9, 2005], Internet <URL: http://www.shinyu.co.jp/> Suguru Gumoto and Kenzo Ito, “Study on the method of identifying living sounds for the purpose of supporting the hearing impaired”, IEICE Technical Report, WIT2002-69, 2002. Shinya Ando, 4 others, “Identification of warning sound for hearing impaired”, IEICE Technical Report, EA2001-119, 2002. Toshiro Oga, Yoshio Yamazaki, Yutaka Kaneda, "Sound System and Digital Processing", Corona Co., Ltd., p. 197-209 Japanese Patent Laid-Open No. 11-120468

  In the acoustic transmission device, the emphasis is on transmitting the sound promptly to the extent that the sound arrival direction is not misidentified, although it is a simple device, rather than determining and transmitting the sound arrival direction very accurately. Accordingly, it is important that the apparatus configuration can be made as small as possible and the amount of calculation for determining the direction of arrival of the sound is not large.

  However, in the above conventional method for estimating the direction of arrival of sound, it is necessary to prepare three or more microphones, which is costly and increases the scale of the apparatus. Analysis of acoustic signals collected from three microphones There is a problem that a considerable amount of computation is required for the above.

  Therefore, in view of the above problems, the problem to be solved by the present invention is to provide an acoustic transmission device capable of determining and transmitting the arrival direction of sound collected by two sound collecting means. It is.

  In order to solve the above-described problems, the present invention provides two sound collecting means having directivity capable of collecting an acoustic signal, and arrival phase differences between the collected sound signals collected by the sound collecting means and / or Based on the magnitude relationship of the arrival level differences, the arrival direction determination means for determining the arrival direction of the acoustic signal in at least about four directions of front, back, left and right, and a predetermined acoustic signal for each collected sound signal collected by each sound collection means And a sound signal determined by the direction-of-arrival determining means when it is determined by the filter means that at least one of the collected sound signals includes a predetermined sound signal. Presenting means for presenting the direction of arrival of the sound to the person, and the sound transmitting device is characterized in that the direction of directivity of each of the sound collecting means is approximately diagonally left rear and diagonally right rear of the person. . By adopting such a configuration, it becomes a small-scale acoustic transmission device, and the cost and cost can be reduced.

  The acoustic transmission device of the present invention includes sound source separation means for separating and outputting each collected sound signal collected by each of the sound collection means into an acoustic signal from each directivity direction of the sound collection means. The filter means may determine whether or not a predetermined sound signal is included for each sound signal output by the sound source separation means. With such a configuration, it is possible to improve the accuracy of determination as to whether or not a predetermined acoustic signal is included in the filter means.

  In the acoustic transmission device of the present invention, the sound collecting means and the presentation means are attached to different parts of a person, and the directivity direction of each sound collecting means is relative to the front, rear, left, and right directions of the presentation means. Angle detection means for detecting a different angle difference, and the direction-of-arrival determination means determines the sound determined from the arrival phase difference and / or the arrival level difference of the collected sound signals collected by the sound collection means. The arrival direction of the acoustic signal may be determined by correcting the arrival direction of the signal based on the angle difference detected by the angle detection means. By adopting such a configuration, it is possible to reduce erroneous determination of the arrival direction of the acoustic signal accompanying the movement of the human body.

  Further, in the acoustic transmission device of the present invention, the presenting means includes at least two vibration devices, and the presenting means is arranged on a person such that each vibration device is positioned on the left body side and the right body side of the person. The vibration intensity of each vibration device that is attached may be different depending on whether the arrival direction is determined to be approximately before or approximately after the arrival direction by the arrival direction determination means. By adopting such a configuration, a further small-scale acoustic transmission device can be obtained, and the cost and cost can be reduced.

  Furthermore, in the acoustic transmission device according to the present invention, the vibration intensity of each of the excitation devices is stronger when it is determined to be approximately later than when the arrival direction determination unit determines that the arrival direction is approximately front. It may be a thing. By setting it as such a structure, a person's attention can be strongly attracted with respect to the acoustic signal from back.

  According to the present invention, since there are two sound pickup means and the direction of arrival of the acoustic signal is presented by at least four directions of the front, back, left and right of the person, the acoustic transmission device can be provided with less equipment and lower cost than the conventional technology. realizable.

  Moreover, according to this invention, the following effects can also be enjoyed. That is, since there are two sound collecting means, the weight of the entire acoustic transmission device can be reduced, and the volume of the device can be reduced. Further, the amount of calculation for analyzing the sound signals collected from the two sound collecting means is the amount of calculation for analyzing the sound signals collected from three or more sound collecting means as in the prior art. Therefore, the calculation can be executed by a small and lightweight arithmetic processing unit. In addition, since such a small and lightweight arithmetic processing device has low power consumption, a power supply device (for example, a battery) of the acoustic transmission device can be a small and light power supply. When a power supply device having the same scale as that of the first embodiment is used, the sound transmission device for a long time can be operated.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 11. Corresponding portions in the drawings are denoted by the same reference numerals, and redundant description will be omitted.
In this embodiment, the case where the acoustic transmission device (A) according to the present invention is worn on a person is taken as an example (see FIGS. 3 and 4), and the direction of sound arrival is set to 4 by using two microphones. It is possible to discriminate and communicate in directions.

  As illustrated in FIGS. 1 and 2, the acoustic transmission device (A) according to the present embodiment includes a sound collection output unit (a), a generalization unit (b), and a presentation unit (c).

The hardware configuration of the supervision unit (b) will be described.
The supervision unit (b) includes an input unit (100) to which a microphone and a gyro sensor of a sound collection output unit (a) described later can be connected, and an output unit (101) to which a vibration device of a presentation unit (c) described later can be connected. ), DSP [Digital Signal Processor] (102) [may include a cache memory or the like. RAM (Random Access Memory) (103), ROM (Read Only Memory) (104), and these input unit (100), output unit (101), DSP (102), RAM (103), ROM A transmission path (105) connected so that data can be exchanged between (104) is provided. Instead of the DSP (102), a CPU (Central Processing Unit) may be used.

  The ROM (104) of the supervision unit (b) stores and stores a program for enabling sound transmission, data necessary for processing of the program, and the like. Further, data obtained by the processing of these programs is appropriately stored and stored in the RAM (103) or the like.

  More specifically, the ROM (104) has a program for converting a sound-collected signal collected by a microphone into a discrete signal (in the time domain), and a frame for cutting out a frame from the discrete signal with an appropriate length. Program, program for converting time domain frame into frequency domain signal (discrete Fourier transform), program for calculating arrival phase difference / arrival level difference from signals picked up by multiple microphones, microphone pointing area A program for selecting frequency components of an acoustic signal from a sound source existing in the sound source, a program for converting a frequency domain signal into a time domain signal (inverse discrete Fourier transform), and an acoustic signal from a sound source existing in a microphone pointing area Program for determining whether or not the target acoustic signal is included, arrival phase difference / arrival level Programs for determining the direction of arrival of sound, a program for controlling the driving of the vibrating device of the presentation unit (c) is stored stored from. In addition, a control program for controlling processing based on these programs is also stored as appropriate.

  In the control section (b) of the acoustic transmission device (A) according to the present embodiment, each program stored in the ROM (104) and data necessary for processing each program are read into the RAM (103) as necessary. The DSP (102) performs interpretation and processing. As a result, the DSP (102) has predetermined functions (A / D conversion unit, frame extraction unit, frequency analysis unit, arrival phase difference / arrival level difference calculation unit, selection unit, signal synthesis unit, filter unit, arrival direction determination. Part, drive control part).

  The sound collection output unit (a), the overall unit (b), the presentation unit (c), and the overall unit (b) are each connected via an electric wire (60). More specifically, the input unit (100) of the control unit (b) and each microphone of the sound collection output unit (a) described later are connected via an electric wire (60), and the output unit of the control unit (b). (101) and each excitation device of the presentation unit (c) described later are connected via an electric wire (60).

  The sound collection output unit (a) of the acoustic transmission device (A) includes a directional 2-channel microphone (12L) and a microphone (12R) that collects ambient sounds, and can be worn on a human head. It has a configuration. Specifically, the sound collection output unit (a) is configured such that each microphone (12L) (12R) is attached to a predetermined position of the belt (11) that can be wound around the head, for example. . Of course, the present invention is not limited to the belt (11). For example, the microphones (12L) and (12R) may be attached to the hat. In other words, what is necessary is just to be able to hold each microphone (12L) (12R) near the head.

  Although there is no absolute limitation on the type of directivity of each microphone (12L) (12R), an omnidirectional (non-directional) microphone is generally used in view of determining the sound arrival direction. Is not preferred. In this embodiment, a unidirectional microphone (including narrow directivity and sharp directivity) is used, and FIG. 5 shows an example in which a unidirectional microphone is used.

  The positions of attaching the microphones (12L) and (12R) to the belt (11) are the directions of the microphones (12L) and (12R) when the sound collection output unit (a) is mounted on a human head (each microphone). The direction of the directivity is preferably symmetrical with respect to the front and rear direction of the person (face is front and back is back) (see angles α and β in FIG. 5). Note that the directivity generally has main lobes and side lobes, but these are omitted and schematically shown in FIG. In addition, the directivity (approximately in the vertical plane) of each microphone (12L) (12R) is approximately when a person looks straight ahead with the sound collection output unit (a) attached to the head. It should be horizontal. However, since the head also moves with human action, it is not particularly limited to attach each microphone so as to be approximately horizontal, and the directivity direction of each microphone (12L) (12R) is directed to the ground. Or in the sky, it is assumed to be approximately horizontal, assuming that it is not common to point it to the sky. In addition, the directivity (approximately in a horizontal plane) of each microphone (12L) (12R) is oblique when a person looks straight at the front with the sound collection output unit (a) attached to the head. It is better to be left rear and diagonally right rear.

On the other hand, the directivity (approximately in a horizontal plane) of each microphone (12L) (12R) may be arranged so as to be diagonally forward left and diagonally forward right. In the present embodiment, in view of the fact that it is often important to promptly transmit rear left and right acoustic information (for example, a warning notification sound) that is difficult to enter the field of view, the detection accuracy of the rear sound is more improved. In order to improve, it is arranged so as to be diagonally left rear and diagonally right rear.
Of course, the directionality (approximately in the horizontal or vertical plane) of each microphone (12L) (12R) may be changed as appropriate according to the usage of the acoustic transmission device (A). .

  The sound collection output unit (a) outputs surrounding sounds collected by the microphones (12L) and (12R) as a sound collection signal L and a sound collection signal R, respectively (step S1). These collected sound signals are input to the A / D conversion unit (2) in the overall unit (b).

  The supervising unit (b) of the sound transmission device (A) directs each microphone (12L) (12R) to each of the sound collecting signal L and the sound collecting signal R output by the sound collecting output unit (a). The sound signal of the sound source existing in the region (hereinafter referred to as “directional region”, see FIG. 5) is separated and extracted (step S2).

  As a means for separating and extracting an acoustic signal from a sound source existing in such a directional region, an explanation will be given by taking as an example the zone separation and sound collection technology (Japanese Patent No. 3355598) that the applicant has patented. Of course, such means is not intended to be limited to the zone separation and collection technique, and there is no limitation to the means as long as an acoustic signal from a sound source existing in the directivity region can be separated and extracted.

Hereinafter, an outline of the zone separation and sound collection technique in the present embodiment will be described with reference to FIGS. 6, 7, 8, and 9. See Reference 1 for details of zone separation sound collection technology.
(Reference 1) Japanese Patent No. 3355598

  The A / D conversion unit (2) in the generalization unit (b) samples each of the sound collection signal L and the sound collection signal R output by the sound collection output unit (a), for example, at a sampling rate of 11,025 Hz. It quantizes suitably and converts into the discrete signal L and the discrete signal R. The A / D conversion from the collected sound signal to the discrete signal is achieved in the same manner as in the known technique, and thus detailed description thereof is omitted. The A / D converter (2) outputs these discrete signals. These discrete signals are input to the frame cutout section (3) in the supervision section (b).

  The frame cutout unit (3) cuts out a discrete signal having a predetermined time length as a frame L and a frame R from each of the discrete signal L and the discrete signal R while moving the start point with a constant time width in the time axis direction. For example, an acoustic signal having a length of 512 sample points is cut out while moving the start point by 256 sample points. For extracting each frame, a known window function (for example, a Hamming window or a Gaussian window) may be applied to the discrete signal. Since the cutout of the frame by applying the window function is achieved in the same manner as in the known technique, a detailed description is omitted. The frame cutout unit (3) outputs each cut out frame. Each of these frames becomes an input to the frequency analysis unit (41) in the supervision unit (b).

  The frequency analysis unit (41) performs discrete Fourier transform on each of the frame L and the frame R to obtain respective discrete spectra. The frequency analysis unit (41) outputs the discrete spectrum L and the discrete spectrum R for the frame L and the frame R, respectively. The discrete spectrum L and the discrete spectrum R are input to the arrival phase difference / arrival level difference calculation unit (42) and the selection unit (43).

  The arrival phase difference / arrival level difference calculation unit (42) in the overall unit (b) is a difference in arrival level for each frequency between the discrete spectrum L and the discrete spectrum R output by the frequency analysis unit (41) and / or The arrival phase difference (arrival time difference) is calculated.

The selection unit (43) in the overall unit (b) outputs the arrival level difference for each frequency between the discrete spectrum L and the discrete spectrum R, and / or the output from the arrival phase difference / arrival level difference calculation unit (42). Based on the arrival phase difference, the frequency component for each frequency is selected from the frequency components of each discrete spectrum. In this selection, for example, when it is determined that the arrival phase difference at a certain frequency corresponds to the arrival phase difference of the acoustic signal from the sound source existing in the directivity region of the microphone (12L), the frequency component at the frequency of the discrete spectrum L Is multiplied by a value close to 1 to 1 as a weight, and a frequency component at the frequency of the discrete spectrum R is multiplied by a value close to 0 to 0.
By such selection, the selection unit (43) outputs a discrete spectrum La composed of frequency components selected as frequency components of the acoustic signal from the sound source existing in the directivity region of the microphone (12L). This discrete spectrum La becomes an input to the signal synthesis unit (44L) in the overall unit (b). The selection unit (43) also outputs a discrete spectrum Ra composed of frequency components selected as frequency components of the acoustic signal from the sound source existing in the directivity region of the microphone (12R). This discrete spectrum Ra becomes an input to the signal synthesis unit (44R) in the overall unit (b).

  The signal synthesizer (44L) performs inverse Fourier transform on the discrete spectrum La and outputs an acoustic signal L from a sound source existing in the directivity region of the microphone (12L). The signal synthesizer (44R) performs inverse Fourier transform on the discrete spectrum Ra and outputs an acoustic signal R from a sound source existing in the directivity region of the microphone (12R). The acoustic signal L and the acoustic signal R output from each signal synthesis unit (44L) (44R) are input to the filter unit (5) in the overall unit (b).

The filter unit (5) determines whether or not the target acoustic signal is included under predetermined conditions for each of the acoustic signal L and the acoustic signal R, and outputs the determination result (step S3). ). The determination result is input to the drive control unit (7) in the overall unit (b). “Target acoustic signal” is generated from, for example, impact sound generated by contact between objects, sudden sound such as car horn / siren, whistle, etc., electrical appliances, etc. There is a notification sound. The “predetermined condition” may be set by paying attention to the acoustic characteristics of such an acoustic signal. For example, when it is determined whether or not the acoustic signal L or the acoustic signal R includes a suddenly generated sound, “the sound pressure level of the acoustic signal L or the acoustic signal R is equal to or higher than a predetermined sound pressure level”. The sound pressure level of the sound signal L or the sound signal R may be a condition that the sound pressure level of the sound signal L or the sound signal R is more than a predetermined difference compared to the sound pressure level of the surrounding background noise. In the case of determining whether or not the sound signal includes a notification sound, it is noted that the sound signal includes a characteristic frequency and pattern as specified in JIS S 0013 of the Japan Standards Association. It may be set on the condition that the frequencies included in L or the acoustic signal R are concentrated on a predetermined frequency. Moreover, you may make it determine whether the acoustic signal L thru | or the acoustic signal R contain the target acoustic signal by combining several conditions. There are various specific processing methods, and an example thereof is disclosed in Reference Document 2.
(Reference 2) Japanese Patent Application Laid-Open No. 2004-240855

  The selection unit (43) and the signal synthesis units (44L) (44R) are constituent elements for separating and extracting acoustic signals from the sound source existing in the directional area (collectively, these are the sound sources. (Described as a separation part (d)). Therefore, when the sound source direction is known in advance, the sound source separation unit (d) is not necessary, and the sound collection signal L and the sound collection signal R output by the sound collection output unit (a) are respectively connected to the filter unit (5 ) Input. In this case, the filter unit (5) determines whether or not the target sound signal is included under a predetermined condition for each of the sound pickup signal L and the sound pickup signal R, and the determination result is obtained. Output.

The arrival direction determination unit (6) in the overall unit (b) outputs the arrival level difference for each frequency between the discrete spectrum L and the discrete spectrum R output by the arrival phase difference / arrival level difference calculation unit (42). Based on the arrival phase difference, the arrival direction of the target acoustic signal is determined by dividing it into four directions, and the determination result is output (step S4). An example of a method for determining in four directions will be described below. First, regarding the arrival level difference for each frequency between the discrete spectrum L and the discrete spectrum R output by the arrival phase difference / arrival level difference calculation unit (42), it is determined that one of the discrete spectra is larger. Ratio (hereinafter referred to as “band ratio”) is obtained for the entire frequency band, and it is determined whether or not the band ratio exceeds a predetermined threshold μ (for example, μ = 0.7) (step S41). Next, when the band ratio determined to be larger in the discrete spectrum L exceeds the predetermined threshold μ, “left” is set as the arrival direction of the target acoustic signal (step S42). On the contrary, when the band ratio determined that the discrete spectrum R is larger than the predetermined threshold μ, “Right” is set as the arrival direction of the target acoustic signal (step S43). When the band ratio determined that either one of the discrete spectra is larger does not exceed the predetermined threshold μ, the microphone having directivity has a high ability to pick up sound in the directional region and each microphone. Paying attention to the positional relationship between (12L) and (12R), the sound pressure level of the collected sound signal picked up by the microphone (12L) or the microphone (12R) is a predetermined threshold value τ (for example, τ = 0.6). If it is larger, “after” is set as the direction of arrival of the target sound (step S44), and conversely if “small” is set, it is set as the direction of arrival of the target sound (step S45). This “predetermined threshold value τ” is determined according to the characteristics of the microphone and the usage environment.
The determination result output by the arrival direction determination unit (6) is input to the drive control unit (7) in the supervision unit (b).

Further, based on the feature that the microphone having directivity has a high ability to pick up sound in the directivity area and the positional relationship between the microphones (12L) and (12R), the following is a modified example of the direction of arrival determination method described above. explain. In this modification, steps S41, S44, S45, and S46 are the same as the above-described determination method, and thus the description thereof is omitted.
In the above arrival direction determination method, in step S42, when the band ratio determined that the discrete spectrum L is larger than the predetermined threshold μ, “left” is set as the arrival direction of the target acoustic signal. . In this modification, when the band ratio determined to be larger in the discrete spectrum L exceeds a predetermined threshold μ, the sound pressure level γ of the collected sound signal collected by the microphone (12L) is appropriately normalized. And a predetermined threshold value ξ ₁ , ξ ₂ (for example, ξ ₁ = 0.4, ξ ₂ = 0.6) is determined (step S42a). When the sound pressure level γ of the collected signal picked up by the microphone (12L) is ξ ₂ <γ, the arrival direction of the target acoustic signal is “left rear” (step S42b). Sound pressure level of the collected sound signal by the microphone (12L) is picked up gamma is, in the case of gamma <xi] ₁ is the arrival direction of the sound signal for the purpose of "left" (step S42c). When the sound pressure level γ of the collected signal picked up by the microphone (12L) is ξ ₁ ≦ γ ≦ ξ ₂ , “left” is set as the arrival direction of the target acoustic signal (step S42d).
Further, in the above arrival direction determination method, in step S43, when the band ratio determined to be larger in the discrete spectrum R exceeds the predetermined threshold μ, the arrival direction of the acoustic signal aimed at “right” I was trying. In this modification, when the band ratio determined to be larger in the discrete spectrum R exceeds a predetermined threshold μ, the sound pressure level γ of the collected signal picked up by the microphone (12R) (normalized appropriately) And a predetermined threshold value ξ ₁ , ξ ₂ (for example, ξ ₁ = 0.4, ξ ₂ = 0.6) is determined (step S43a). When the sound pressure level γ of the collected signal picked up by the microphone (12R) is ξ ₂ <γ, the arrival direction of the target acoustic signal is “right rear” (step S43b). Sound pressure level of the collected sound signal by the microphone (12R) is picked up gamma is, in the case of gamma <xi] ₁ is the arrival direction of the sound signal for the purpose of "front right" (step S43c). When the sound pressure level γ of the collected signal picked up by the microphone (12R) is ξ ₁ ≦ γ ≦ ξ ₂ , “right” is the arrival direction of the target acoustic signal (step S43d).

  In the determination method of the arrival direction as described above, for example, when a loud (predetermined) sound is generated in front of a person or a small (predetermined) sound is generated behind the person, an erroneous determination in the front-rear direction occurs. Sometimes. However, since the arrival direction determination by the arrival direction determination unit (6) is an arrival direction determination for a frame having a relatively short time width extracted by the frame extraction unit (3), some misjudgment. It is more difficult for humans to detect, and in an acoustic transmission device, it is more important to quickly transmit the presence and direction of the target acoustic signal to the person than to accurately determine the direction of arrival, Normally, recognition of the surrounding situation by a sensory organ other than the auditory sense is performed, so even if there is some misjudgment, it does not cause a big problem.

Before describing the operation of the drive control unit (7), the presentation unit (c) of the acoustic transmission device (A) will be described.
The presentation unit (c) of the acoustic transmission device (A) includes four vibration devices and is configured to be worn on a human waist. Specifically, for example, the presenting unit (c) has each vibration device (72L) (72R) (72F) (72B) attached to a predetermined position of the belt (71) that can be wound around the waist. It has become a thing. Of course, the present invention is not limited to the belt (71), and may be any apparatus capable of holding the vibration devices (72L), (72R), (72F), and (72B) near the waist.

  The position of attaching each of the vibration devices (72L), (72R), (72F), and (72B) to the belt (71) is the position of the vibration devices (72L) (72R) ( 72F) (72B) is preferably located near the front, back, left, and right of the person. That is, the vibration device (72F) is placed on the person's waist (front), the vibration device (72B) is placed on the person's waist (rear), and the vibration device (72L) is placed on the person's waist (left). A vibration device (72R) is provided on (right).

  The drive control unit (7) controls the driving of the vibration exciter of the presentation unit (c) using the determination result output by the filter unit (5) and the determination result output by the arrival direction determination unit (6) as inputs. (Step S5). Specifically, the drive control unit (7) first determines the determination result output by the filter unit (5). When the determination result is not “the target acoustic signal is included”, the excitation device of the presentation unit (c) is not driven. On the other hand, when the determination result is “the target acoustic signal is included”, the appropriate excitation device is driven based on the determination result output by the arrival direction determination unit (6). . For example, when the determination result output by the arrival direction determination unit (6) is “right”, the vibration device (72R) provided in the waist (right) is driven to vibrate. This vibration is transmitted to the person, and the person can perceive the vibration and can recognize the presence of the target sound and its arrival direction (in this case, right).

  In the case of the determination method described in the modification of the arrival direction determination method, for example, when the determination result output by the arrival direction determination unit (6) is “right rear”, the waist ( The vibration device (72R) provided in the right) and the vibration device (72B) provided in the waist (rear) may be driven and vibrated together.

  Note that the filter unit (5) outputs not only the determination result but also the acoustic signal output from the signal synthesis unit (44L) (44R). The drive control unit (7) May be converted to a perceivable frequency, and the vibration device of the presentation unit (c) may be driven so as to vibrate at this frequency.

  Further, the number of vibration devices of the presentation unit (c) may be two. An example of a method for distinguishing the four directions with the two vibrating devices is as follows. Here, it is assumed that the two vibration devices (72R) (72L) are provided in the waist (right) and the waist (left). For example, when the arrival direction is left or right, the vibrator (72L) provided in the waist (left) or the vibrator (72R) provided in the waist (right) is driven to vibrate. When the arrival direction is before or after, the left and right vibration devices (72L) and (72R) are driven together. When the arrival direction is the front, the vibration is weak, and when the arrival direction is the rear, the vibration is strong. To do. On the other hand, it is possible to use strong vibration when the direction of arrival is earlier and weak vibration when the direction of arrival is later, but the sound from the front that can be visually judged to some extent by the hearing impaired Since sound information from the rear, left and right, which is relatively difficult to judge visually, is more important, it is preferable to generate strong vibration when the direction of arrival is a later sound.

  The presenting method of the presenting unit (c) is not limited to the presenting method of vibration as long as it is possible to present the presence of sound and its arrival direction to a person. For example, instead of the vibration device as described above, it may be a method of visually displaying the presence and direction of arrival of sound on a portable display. For example, the direction of arrival of sound centering on the position of a person. Is displayed with an arrow or character.

In the present embodiment, the sound collection output unit (a) is mounted on the head and the presentation unit (c) is mounted on the waist as illustrated in FIGS. 3 and 4. In this case, for example, when looking back in response to sound from the back (that is, vibration of the vibration exciter (72B)), the head may rotate horizontally with the position of the waist approximately unchanged. Then, there is a possibility that the arrival direction of the sound collected by the sound collection output unit (a) may not be accurately grasped because the direction of arrival of the driven vibration device does not match. As a method of dealing with such a possibility, the sound collection output unit (a) and the presentation unit (c) are not attached to the sound collection output unit (a) and the presentation unit (c) in separate parts. There is a method of attaching to the same part. That is, for example, the microphone (12L) (12R) may be provided on the belt (71).
Alternatively, when the sound collection output unit (a) and the presentation unit (c) are attached to different parts as described in the above embodiment, a sensor that can detect the position and angle, for example, a gyro sensor (80) is provided in the sound collection output unit (a) (the position of the gyro sensor (80) attached to the sound collection output unit (a) is not limited), and the gyro sensor (80) has a rotation angle θ of the head. Is detected and output (see FIGS. 2, 4, 8, and 9). The rotation angle θ output by the gyro sensor (80) is input to the arrival direction determination unit (6). Then, the arrival direction determination unit (6) rotates the arrival direction determination reference in the same direction (angle θ) by the rotation angle θ output by the gyro sensor (80), and determines the arrival direction based on this reference. You may do it. In this way, for example, when the head rotates horizontally 90 degrees to the right, even if the target sound is generated behind the head (that is, the left direction of the waist), the arrival direction The determination unit (6) determines the arrival direction as “left”, and the presentation unit (c) drives the left vibration device (72L).

  Since the present invention can transmit the presence and direction of sound to a person, the hearing is limited like a person with hearing impairment or a person wearing a helmet that covers both ears. This is useful for substituting and assisting the hearing of those who have been treated.

The hardware structural example of an acoustic transmission apparatus (A). The hardware structural example of an acoustic transmission apparatus (A) provided with the gyro sensor (80). The figure which showed the example which mounted | wore the person with the acoustic transmission apparatus (A). The figure which showed the example which mounted | wore the person with the acoustic transmission apparatus (A) provided with the gyro sensor (80). The figure which illustrated the directivity of each directional microphone (12L) (12R). The functional block diagram of an acoustic transmission apparatus (A). The functional block diagram of the acoustic transmission apparatus (A) which is not provided with a sound source separation part (d). The functional block diagram of the acoustic transmission apparatus (A) provided with the gyro sensor (80). The functional block diagram of the acoustic transmission apparatus (A) which is provided with a gyro sensor (80) but is not provided with a sound source separation part (d). The figure which shows the processing flow in an acoustic transmission apparatus (A). The figure which shows the processing flow of the arrival direction determination in an arrival direction determination part (6). The figure which shows the modification of the processing flow of the arrival direction determination in the arrival direction determination part (6) (the 1). The figure which shows the modification of the processing flow of the arrival direction determination in the arrival direction determination part (6) (the 2). The figure which shows the modification of the processing flow of the arrival direction determination in the arrival direction determination part (6) (the 3).

Explanation of symbols

A sound transmission device a sound collection output unit b supervision unit c presentation unit d sound source separation unit 12L directional microphone 12R directional microphone 2 A / D conversion unit 3 frame extraction unit 41 frequency analysis unit 42 arrival phase difference / arrival level difference Calculation unit 43 Selection unit 44L Signal synthesis unit 44R Signal synthesis unit 5 Filter unit 6 Arrival direction determination unit 7 Drive control unit 72F Excitation device 72B Excitation device 72L Excitation device 72R Excitation device 80 Gyro sensor

Claims (5)

Two sound collecting means having directivity capable of collecting an acoustic signal;
Direction-of-arrival determining means for determining the direction of arrival of an acoustic signal in at least four directions, front, back, left, and right of a person, based on the magnitude relationship between the arrival phase difference and / or the arrival level difference of each collected sound collected by each sound collecting means When,
Filter means for determining whether or not each sound collection signal collected by each sound collection means includes a predetermined acoustic signal;
Presenting means for presenting to the person the arrival direction of the acoustic signal determined by the arrival direction determining means when it is determined by the filter means that at least one of the collected sound signals includes a predetermined acoustic signal; Prepared,
An acoustic transmission device characterized in that the direction of directivity of each of the sound collecting means is approximately diagonally left rear and approximately diagonally right rear of a person. Each sound collection signal collected by each sound collection means comprises sound source separation means for separating and outputting sound signals from the directivity directions of the sound collection means,
2. The acoustic transmission device according to claim 1, wherein the filter means determines whether or not a predetermined acoustic signal is included for each of the acoustic signals output by the sound source separation means. When each of the sound collection means and the presentation means are worn on different parts of a person,
An angle detection means for detecting a relative angle difference between the direction of directivity of each sound collection means and the front-rear and left-right directions in the presentation means;
The direction-of-arrival determining means detects the direction of arrival of the acoustic signal determined by the magnitude relationship between the arrival phase difference and / or the arrival level difference of each collected signal collected by each sound collecting means by the angle detecting means. The acoustic transmission device according to claim 1, wherein the direction of arrival of the acoustic signal is determined by correcting based on the angle difference. The presenting means comprises at least two vibration devices,
The presenting means is attached to a person so that each vibration device is located on the left body side and the right body side of the person,
The vibration intensity of each vibration device is different depending on whether the direction of arrival is determined to be approximately before or approximately after the arrival direction by the arrival direction determining means. 4. The acoustic transmission device according to any one of 3. 5. The vibration intensity of each of the vibration exciting devices is stronger when the arrival direction is determined to be approximately later than when the arrival direction is determined to be approximately before by the arrival direction determination means. The acoustic transmission device described in 1.

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