Position estimation device, position estimation method, and program

Abstract

Provided are a position estimation device and the like for estimating whether or not a position of an open-ear earphone worn on the ear is correct. The position estimation device comprises: a storage unit which stores a resonance frequency f1 of a space formed between the ear of a user and the open-ear earphone; and an estimation unit which obtains a resonance frequency f2 of the space formed between the ear of the user and the open-ear earphone through use of a sound collection signal obtained by a microphone included in the open-ear earphone collecting sound when a predetermined signal is reproduced by a speaker included in the open-ear earphone in a state in which the open-ear earphone is worn by the user and estimates, when the resonance frequencies f1 and f2 match, that the open-ear earphone is worn at an ideal position on the ear of the user. The resonance frequency f1 is obtained through use of a sound collection signal acquired by the sound collection using the microphone when the predetermined signal is reproduced by the speaker in the state in which the open-ear earphone is worn at the ideal position on the ear of the user.

Description

[Technical Field]

[0001] The present invention relates to a technology for reproducing acoustic signals with open-ear earphones that do not block the external auditory canal. [Background Art]

[0002] Earphones include canal-type earphones that block the external auditory canal, and open-ear earphones that do not block the external auditory canal. Canal-type earphones are provided with an "ear tip" shaped like an earplug at the tip of the earphone, which hermetically seals the external auditory canal. For canal-type earphones, it is necessary to select an ear tip that matches the size of the user's ear canal, but it is difficult for the user themselves to determine whether the ear tip is of an optimal size. Accordingly, Non-Patent Document 1 is known as a conventional technique for determining whether a canal-type earphone of an optimal size is worn. Non-Patent Document 1 describes that by reproducing sound while the canal-type earphone is worn, it is possible to check whether the canal-type earphone is worn to hermetically seal the external auditory canal. [Prior Art Documents] [Non-Patent Documents]

[0003] [Non-Patent Document 1] "Select the perfectly fitting AirPods Pro ear tip and perform the ear tip fit test", [online], 2020, Apple Inc., [searched October 17, 2022 Reiwa], Internet <URL:https: / / support.apple.com / ja-jp / HT210633> [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the case of open-ear earphones, the earphone is worn by hooking a component of the earphone on the portion called the concha of the auricle (the portion of the entire ear that is exposed outside). Since open-ear earphones do not use ear tips, size adjustment is unnecessary.

[0005] However, users may not be able to determine whether open-ear earphones are properly positioned in their ears. If open-ear earphones are not worn correctly, the acoustic characteristics may change, leading to problems such as altered sound characteristics and impaired directional perception of spatial sound.

[0006] The present invention aims to provide a position estimation device, a position estimation method, and a program for estimating whether the position in which open-ear earphones are worn on the ear is correct. [Means for solving the problem]

[0007] To solve the above problems, according to one aspect of the present invention, the position estimation device includes a storage unit that stores the resonant frequency f1 of the space formed by the user's ear and the open-ear type earphone, and an estimation unit that obtains the resonant frequency f2 of the space formed by the user's ear and the open-ear type earphone using an acquired sound signal obtained by picking up sound with a microphone included in the open-ear type earphone when a predetermined signal is played back with a speaker included in the open-ear type earphone while the user is wearing the open-ear type earphone, and estimates that the open-ear type earphone is worn in an ideal position on the user's ear if the resonant frequencies f1 and f2 match. The resonant frequency f1 is obtained using an acquired sound signal obtained by picking up sound with a microphone when a predetermined signal is played back with a speaker while the open-ear type earphone is worn in an ideal position on the user's ear. [Effects of the Invention]

[0008] According to the present invention, it is possible to estimate whether the position in which an open-ear type earphone, including a speaker and a microphone, is correctly worn on the ear can be determined without using any special equipment. [Brief explanation of the drawing]

[0009] [Figure 1] A diagram illustrating the simulation status. [Figure 2] A diagram showing the relationship between the volume of a space and its resonant frequency. [Figure 3] This diagram shows the frequency response measured while changing the wearing position of open-ear headphones. [Figure 4] A diagram showing an example of the mounting position. [Figure 5] Functional block diagram of the position estimation device according to the first embodiment. [Figure 6] A diagram showing an example of the processing flow of the position estimation device according to the first embodiment. [Figure 7] A diagram showing an example of a computer configuration to which this method is applied. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below. In the drawings used in the following description, components with the same function or steps that perform the same processing will be denoted by the same reference numerals, and redundant explanations will be omitted.

[0011] <Key points of the first embodiment> In this embodiment, the correct wearing position is estimated by utilizing the resonant frequency created between the open-ear type earphone and the ear.

[0012] Open-ear earphones often have a microphone built into the housing for voice acquisition, not only for listening to music, but also for connecting to smartphones and PCs to enable voice calls and voice recognition. In addition to the microphone for voice acquisition, they often also have a microphone built into the housing for acquiring ambient sounds to achieve noise cancellation and echo cancellation. The open-ear earphone according to this embodiment also includes a speaker and a microphone.

[0013] In this embodiment, the resonant frequency changes depending on the volume of the space formed between the ear and the housing of the open-ear earphone, and this phenomenon is used to estimate whether the open-ear earphone is correctly positioned on the ear.

[0014] For example, a predetermined signal is reproduced from a speaker included in an open-ear earphone, and the reproduced sound is collected by a microphone included in the open-ear earphone. A resonance frequency generated in a space between an ear and a housing is obtained from a frequency characteristic of the collected acoustic signal, and it is estimated from the obtained resonance frequency whether the wearing position of the open-ear earphone is a usual wearing position (appropriate wearing position) or a wearing position different from the usual wearing position (inappropriate wearing position).

[0015] It will be described that the resonance frequency changes according to the volume of a space formed by an ear and a housing of the open-ear earphone. The relationship between the volume of the space and the resonance frequency was obtained by simulation. FIG. 1 is a diagram for explaining a situation of the simulation, and FIG. 2 is a diagram showing the relationship between the volume of the space and the resonance frequency. In this simulation, the volume of the space 20 is changed by changing the position of the housing 10 of the open-ear earphone. In this simulation, 200mm 3 the volume is changed for each, and 600mm 3 to 1400mm 3 frequency characteristics were obtained. In the simulation, the sound pressure level at the eardrum position and the sound pressure level at a position 150 mm on the rear side of the housing were obtained. Note that the rear surface of the housing is a surface opposite to a surface on which the earphone is worn, and the position 150 mm on the rear side of the housing is a position 150 mm away from the rear surface of the housing in a direction toward the rear surface of the housing when viewed from the center of the housing.

[0016] As shown in FIG. 2, at both the eardrum position and the position 150 mm on the rear side of the housing, the position of the peak frequency appearing in a band of 10 kHz to 11 kHz was shifted. Note that as the space becomes smaller, the position of the peak frequency shifts to a higher frequency band. In the present embodiment, by observing the position of the peak frequency, it is determined whether the earphone is worn at a position different from a usual position.

[0017] As a method of acquiring a resonance frequency, an impulse response is obtained by the TSP method, and the resonance frequency is obtained from the impulse response. For example, a TSP (Time Stretched Pulse) signal is reproduced from a speaker included in an open-ear earphone, and the reproduced signal is collected by a microphone included in the open-ear earphone. A time-reversed TSP signal is convolved with the collected signal to compress (impulsize) the stretched signal, thereby obtaining the impulse response.

[0018] FIG. 3 shows frequency characteristics measured while changing the wearing position of an open-ear earphone. FIG. 4 is a diagram showing an example of wearing positions. Wearing positions 1 and 3 show examples where the open-ear earphone is worn at a position different from the normal wearing position (inappropriate wearing position), and wearing positions 2 and 4 show examples where the open-ear earphone is worn at the same position as the normal wearing position (appropriate wearing position).

[0019] As shown in FIG. 3, when the open-ear earphone is worn at an appropriate wearing position, a peak occurs at the same frequency, and when the open-ear earphone is worn at an inappropriate wearing position, the frequency of the peak is different. From this, by checking the resonance frequency generated between the ear and the open-ear earphone, it can be estimated whether the wearing position is appropriate or inappropriate.

[0020] With such a configuration, it is possible to estimate whether the wearing position is correct from the speaker and microphone included in a general open-ear earphone without using a special sensor or the like, and it is possible to solve the problem that the wearing position occurring in an open-ear earphone cannot be fixed to an appropriate position. The invention of the present application is particularly useful for ear-hook type open-ear earphones, since the wearing position thereof is likely to shift.

[0021] <First Embodiment> FIG. 5 is a functional block diagram of a position estimating device according to the first embodiment, and FIG. 6 shows a processing flow thereof.

[0022] The position estimation device includes a generation unit 110, a storage unit 130, and an estimation unit 140.

[0023] The position estimation device is connected to the open-ear earphone 90 via wired or wireless communication and outputs a predetermined signal reproduced by the speaker 91 included in the open-ear earphone 90. Furthermore, the position estimation device takes as input the sound-collected signal obtained by capturing the predetermined signal reproduced by the speaker 91 with the microphone 92 included in the open-ear earphone 90.

[0024] The position estimation device estimates the wearing position of the open-ear earphones from the sound-collected signal and outputs the estimation result.

[0025] A position estimation device is a special device configured by loading a special program onto a known or dedicated computer having, for example, a central processing unit (CPU) and main memory (RAM). The position estimation device executes each process under the control of, for example, the central processing unit. Data input to the position estimation device and data obtained from each process are stored, for example, in main memory, and the data stored in main memory is read to the central processing unit as needed and used for other processes. Each processing unit of the position estimation device may be composed of hardware such as integrated circuits, at least in part. Each storage unit of the position estimation device can be composed of, for example, main memory such as RAM (Random Access Memory), or middleware such as a relational database or key-value store. However, each storage unit does not necessarily have to be located inside the position estimation device; it may be composed of auxiliary storage devices made of semiconductor memory elements such as hard disks, optical disks, or flash memory, and may be located outside the position estimation device.

[0026] The estimation process consists of a preparation stage and an estimation stage, which are performed before estimating the mounting position. First, let's explain the preparation stage.

[0027] <Preparation Stage> First, users of open-ear earphones should wear them in the ideal position (appropriate wearing position) on the auricle. Whether or not the earphones are worn in the ideal position can be determined subjectively by the user, or objectively by a third party with specialized knowledge who can verify the wearing position.

[0028] The generation unit 110 generates a predetermined signal to be reproduced by the speaker 91 (S101) and outputs it to the speaker 91. For example, the predetermined signal is a TSP signal.

[0029] With the open-ear earphones positioned ideally in the user's ears, a predetermined signal is played back through the speaker 91 (S103).

[0030] The sound played by speaker 91 is picked up by microphone 92 (S105).

[0031] The estimation unit 140 takes the sound-collecting signal obtained by the microphone 92 as input, and uses the sound-collecting signal to obtain the resonant frequency f2 of the space formed between the user's ear and the open-ear type earphone (S109), and stores it in the memory unit 130 (S111). For example, if the predetermined signal is a TSP signal, the estimation unit 140 compresses (impulses) the stretched signal by convolving a time-reversed TSP signal into the sound-collecting signal using the TSP method to obtain an impulse response, and then obtains the resonant frequency f2 from the impulse response.

[0032] The preparation stage includes the processes S101 to S111 described above. Next, the estimation stage will be explained.

[0033] <Estimated stage> First, users of open-ear earphones wear the earphones on their outer ears.

[0034] The generation unit 110 generates a predetermined signal to be reproduced by the speaker 91 (S201) and outputs it to the speaker 91. For example, the predetermined signal is the same signal used in the preparation stage.

[0035] With the open-ear earphones in the user's ears, a predetermined signal is played back through speaker 91 (S203).

[0036] The sound played by speaker 91 is picked up by microphone 92 (S205).

[0037] The estimation unit 240 takes the sound-collecting signal obtained by the microphone 92 as input and uses the sound-collecting signal to obtain the resonant frequency f1 of the space formed by the user's ear and the open-ear type earphone (S209). The method for obtaining the resonant frequency from the sound-collecting signal is the same as in the preparation stage. The estimation unit 240 refers to the resonant frequency f2 stored in the memory unit 130, and if the resonant frequencies f1 and f2 match (YES in S211), it estimates that the open-ear type earphone is fitted in the ideal position on the user's ear and outputs an estimation result indicating that the fitting position is appropriate (S213). If the resonant frequencies f1 and f2 do not match (NO in S211), the estimation unit 240 estimates that the open-ear type earphone is not fitted in the ideal position on the user's ear and outputs an estimation result indicating that the fitting position is inappropriate (S215). Note that the resonant frequencies f1 and f2 matching includes not only cases where they match perfectly, but also cases where the difference between the resonant frequencies f1 and f2 is within a predetermined range. In actual use, even when open-ear earphones are worn in the correct position, their position subtly changes, and the resonant frequency also subtly changes accordingly. Therefore, resonant frequencies f1 and f2 are considered to coincide when the difference between them falls within the range that can be considered as if the earphones were worn in an ideal position.

[0038] <Examples> In this embodiment, the position estimation device is implemented on a smartphone.

[0039] First, let me explain the preparation stage.

[0040] When a smartphone equipped with a position estimation device and an open-ear earphone 90 are connected via wired or wireless communication, the position estimation application is automatically launched, or initiated by the user, and the preparatory processing is performed.

[0041] When the application is launched, the location estimation device displays a message on the smartphone's touch panel prompting the user to place the open-ear earphones 90 in the correct position and play a predetermined signal. For example, the location estimation device displays a play button along with the message, "Place the open-ear earphones 90 in the correct position and tap the 'Play' button."

[0042] When an operation is performed that intends to play a predetermined signal (for example, when the "Play" button is tapped), the position estimation device generates a predetermined signal (S101) and plays it through the speaker 91 (S103). Furthermore, the sound played through the speaker 91 is picked up by the microphone 92 (S105), and the position estimation device uses the picked-up signal to obtain a resonant frequency f2 (S109) and stores it in the memory unit 130 (S111). If the obtained resonant frequency f2 is within an appropriate range, the position estimation device displays a message on the smartphone's touch panel indicating that the preparation for position estimation is complete. For example, the position estimation device displays the message, "The appropriate position of the open-ear earphone 90 has been registered." If the obtained resonant frequency f2 is not within an appropriate range, the position estimation device displays a message on the smartphone's touch panel indicating that position estimation is not complete. For example, the position estimation device displays a message saying, "The open-ear earphone 90 is not properly positioned. Please reposition it correctly and tap the 'Play' button again," along with a play button, and repeats the above process S101 to S111. The appropriate range for the resonant frequency f2 can be determined in advance through experimentation or simulation, taking into account various ear shapes and sizes.

[0043] Next, I will explain the estimation stage.

[0044] When a smartphone equipped with a position estimation device and an open-ear earphone 90 are connected via wired or wireless communication, the position estimation application is automatically launched, or initiated by the user, and the estimation process is executed.

[0045] When the application is launched, the position estimation device automatically generates a predetermined signal (S201) and plays it back through the speaker 91 (S203). Furthermore, the sound played back through the speaker 91 is picked up by the microphone 92 (S205), and the resonant frequency f1 is obtained using the picked-up signal (S209). If the obtained resonant frequency f1 matches the resonant frequency f2 stored in the memory unit 130 (YES in S211), the position estimation device may display a message on the smartphone's touch panel indicating that the open-ear earphones 90 are properly positioned, or it may choose not to display any message (in this case, the absence of a message means that the open-ear earphones 90 are properly positioned). If the resonant frequencies f1 and f2 do not match (NO in S211), the position estimation device displays a message on the smartphone's touch panel indicating that the open-ear earphones 90 are not properly positioned, along with a message prompting the user to readjust the open-ear earphones 90 to the correct position. For example, the position estimation device displays a message saying, "The open-ear earphone 90 is not properly positioned. Please reposition it correctly and tap the 'Complete' button," along with a "Complete" button. When the "Complete" button is tapped, the above processes S201 to S211 are repeated.

[0046] <Effects> With the above configuration, it is possible to estimate whether the position of the open-ear earphone, including the speaker and microphone, on the ear is correct without using any special equipment.

[0047] <Example 1> In this embodiment, a predetermined signal is generated by the generation unit 110, but a predetermined signal that has been generated in advance may be stored in a storage unit (not shown) and output to the speaker 91. In this case, the position estimation device does not need to include the generation unit 110.

[0048] <Other variations> The present invention is not limited to the embodiments and modifications described above. For example, the various processes described above may not only be performed sequentially as described, but may also be performed in parallel or individually as needed, depending on the processing capacity of the device performing the processes. Other modifications can be made as appropriate without departing from the spirit of the present invention.

[0049] <Program and recording medium> The various processes described above can be carried out by loading a program that executes each step of the above method into the recording unit 2020 of the computer 2000 shown in Figure 7, and then causing the control unit 2010, input unit 2030, output unit 2040, display unit 2050, etc. to operate.

[0050] The program describing this process can be recorded on a computer-readable recording medium. Any computer-readable recording medium can be used, such as a magnetic recording device, optical disc, magneto-optical recording medium, or semiconductor memory.

[0051] Furthermore, this program may be distributed, for example, by selling, transferring, or lending portable recording media such as DVDs or CD-ROMs on which the program is recorded. Alternatively, the program may be stored in the storage device of a server computer and distributed by transferring the program from the server computer to other computers via a network.

[0052] A computer executing such a program may, for example, first store the program recorded on a portable storage medium or a program transferred from a server computer in its own storage device. Then, when processing is to be executed, the computer reads the program stored on its own storage medium and executes the processing according to the read program. Alternatively, the computer may directly read the program from the portable storage medium and execute the processing according to that program, or it may sequentially execute the processing according to the received program each time a program is transferred to it from a server computer. Furthermore, the above processing may be executed by a so-called ASP (Application Service Provider) type service, where the server computer does not transfer programs to this computer, but the processing function is realized only by execution instructions and result acquisition. In this form, the program includes information used for processing by an electronic computer that is equivalent to a program (data that is not a direct instruction to the computer but has the property of defining the processing of the computer, etc.).

[0053] Furthermore, in this configuration, the device is configured by executing a predetermined program on a computer, but at least a part of these processes may be implemented in hardware.

Claims

1. The resonant frequency f of the space formed between the user's ear and the open-ear earphones. 1 A memory unit that stores, When the user wears the open-ear earphones, a predetermined signal is played back through the speaker included in the open-ear earphones, and the sound picked up by the microphone included in the open-ear earphones is used to determine the resonant frequency f of the space formed between the user's ear and the open-ear earphones. 2 Obtaining the resonant frequency f 1 and f 2 If the two conditions are met, the estimation unit estimates that the open-ear earphone is fitted to the user's ear in an ideal position, The aforementioned resonant frequency f 1 This is obtained using the sound pickup signal obtained by the microphone when the predetermined signal is played back by the speaker while the open-ear type earphone is worn in an ideal position on the user's ear. Location estimation device.

2. The resonant frequency f of the space formed by the user's ear and the open-ear earphone, which is performed by a computer. 1 A memory step to remember, executed by a computer, in a state where the open-ear earphones are worn by a user, when a predetermined signal is reproduced by a speaker included in the open-ear earphones, using a collected sound signal obtained by sound collection with a microphone included in the open-ear earphones, the resonance frequency f of the space formed between the user's ear and the open-ear earphones 2 is obtained, and when the resonance frequency f 1 and f 2 match, an estimation step of estimating that the open-ear earphones are worn at an ideal position on the user's ear. The aforementioned resonant frequency f 1 This is obtained using the sound pickup signal obtained by the microphone when the predetermined signal is played back by the speaker while the open-ear type earphone is worn in an ideal position on the user's ear. Location estimation method.

3. A program for causing a computer to function as a position estimation device according to claim 1.

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