JP7740558B2 - Transfer characteristic correction device, transfer characteristic correction method, and program - Google Patents

Description

This disclosure relates to a transfer characteristic correction device, a transfer characteristic correction method, and a program that correct deviations in transfer characteristics due to the wearing position each time a wearable speaker that does not block the ear canal (hereinafter referred to as a wearable open-ear speaker) is used to reproduce stereophonic sound.

Surface-sound reproduction is a technology that reproduces sound through speakers (e.g., wearable speakers, headphones, earphones) as if the sound were coming from a source outside the speaker. In surround-sound reproduction, the transmission characteristics of the sound from the speakers to the user's ears have a significant impact on the sense of sound source positioning.

In order to accurately perceive the sense of positioning, it is necessary to cancel out the sound transmission characteristics resulting from the wearable speaker housing being close to the ear, and to make the frequency characteristics between the sound you want to hear and the sound you actually hear as close to flat as possible.

Non-patent document 1 discloses a transfer characteristic correction system that uses an adaptive filter and has microphones placed on the outside and inside of headphones and inserted into the ear.

Natural Listening over Headphones in Augmented Reality Using Adaptive Filtering Techniques, Rishabh Ranjan and Woon-Seng Gan, IEEE/ACM TASLP, vol. 23, no. 11, NOVEMBER 2015

When trying to reproduce surround sound using wearable open-ear speakers, the transmission characteristics specific to the hardware affect the sound, reducing the surround sound effect.

As shown in Figure 1, wearable open-ear speakers require correction to cancel out the transfer characteristics specific to the hardware, i.e., the transfer characteristics shown within the dashed frame in the figure. However, wearable open-ear speakers vary greatly in their position with each use compared to headphones, so it was not possible to measure the transfer characteristics depending on the wearing position in advance.

Note that the transfer characteristic correction system in Non-Patent Document 1 is based on the assumption that the wearable speaker blocks the ear canal, and is not applicable to wearable open-ear speakers.

Therefore, the present disclosure aims to provide a transfer characteristic correction device that allows a user to select parameters for equalization that cancels out the transfer characteristic.

The transfer characteristic correction device disclosed herein includes a display control unit, an input receiving unit, and an equalizer processing unit.

The display control unit controls the display of the transfer characteristics from the speaker driver of the wearable open-ear speaker to the entrance of the ear canal in the form of a graphical equalizer.The input receiving unit determines correction equalizer parameters, which are parameters for correcting the transfer characteristics, based on user input to the graphical equalizer.The equalizer processing unit performs equalization on the acoustic signal based on the correction equalizer parameters.

The transfer characteristic correction device disclosed herein allows the user to select parameters for equalization that cancel out the transfer characteristic.

FIG. 1 is a diagram illustrating a problem with the conventional technology. FIG. 2 is a block diagram showing the functional configuration of the transfer characteristic correction device according to the first embodiment. 4 is a flowchart showing the operation of the transfer characteristic correction device according to the first embodiment. 3A and 3B are diagrams showing examples of acoustic characteristic correction performed by the transfer characteristic correction device of the first embodiment. FIG. 10 is a diagram showing an example of correction equalizer parameters. FIG. 10 is a diagram showing an example of a correction equalizer. FIG. 10 is a diagram showing an example of transfer characteristics after correction. FIG. 2 is a diagram showing an example of the functional configuration of a computer.

The following describes in detail the embodiments of the present disclosure. Components having the same functions are assigned the same numbers, and duplicate explanations will be omitted.

The functional configuration of the transfer characteristic correction system and transfer characteristic correction device of Example 1 will be described below with reference to Figure 2. As shown in the figure, the transfer characteristic correction system 1 includes a wearable open-ear speaker 11, a transfer characteristic correction device 12, and a monitor 13. Examples of wearable open-ear speakers include open-ear earphones, open-ear headphones, and neck speakers.

The transfer characteristic correction system 1 is characterized by including an interface that displays the transfer characteristics between the wearable open-ear speaker 11 and the user in the form of a graphical equalizer on the monitor 13 and allows the user to select parameters for equalization.

The transfer characteristic correction device 12 includes a transfer characteristic measurement unit 121, a display control unit 122, an input reception unit 123, and an equalizer processing unit 124. The operation of each component within the transfer characteristic correction device 12 will be described in detail below with reference to Figure 3.

<Transfer characteristic measuring unit 121>
The transfer characteristic measurement unit 121 uses any impulse response measurement method to measure the transfer characteristic from the speaker driver of the wearable open-ear speaker 11 to the entrance of the ear canal (S121). Note that if the transfer characteristic from the wearable open-ear speaker to the ear canal is measured and recorded in advance using a separate device, the transfer characteristic measurement unit 121 can be omitted.

<Display control unit 122>
The display control unit 122 executes control to display the measured transfer characteristics in the form of a graphical equalizer on the monitor 13 (S122). Using the displayed graphical equalizer, the user starts inputting so that the measured transfer characteristics become flat.

<Input Receiving Unit 123>
The input receiving unit 123 receives a user input for the displayed graphical equalizer, and determines correction equalizer parameters, which are parameters for correcting the transfer characteristics, based on the received user input (S123).

<Equalizer Processing Unit 124>
The equalizer processing unit 124 forms an equalizer for correcting the transfer characteristic based on the corrective equalizer parameters, and performs equalization on the acoustic signal (S124).

When measuring transfer characteristics in real time, it is preferable for the equalizer processing unit 124 to interactively adjust parameters via acoustic processing software (equivalent to Human-in-the-Loop, see the dashed line in Figure 2).

Specifically, the equalizer processing unit 124 outputs the acoustic signal after equalization to the transfer characteristic measurement unit 121, which re-measures the transfer characteristic based on the acoustic signal after equalization, and the display control unit 122 controls the display of the re-measured transfer characteristic on the monitor 13 in the form of a graphical equalizer.

This allows the user to repeatedly select correction equalizer parameters based on their own sense, and by performing equalization on the audio signal based on the repeatedly selected correction equalizer parameters, the sense of positioning can be flexibly improved.

Figure 4 shows an example of acoustic characteristic correction. Figure 5 shows an example of correction equalizer parameters. Figure 6 shows an example of a correction equalizer (solid line graph). Figure 7 shows an example of transfer characteristics after correction. In Figure 7, an example of transfer characteristics before correction is shown by a dashed line graph, and an example of transfer characteristics after correction is shown by a solid line graph. As shown in the figure, it can be seen that correction by the transfer characteristic correction system 1 and transfer characteristic correction device 12 of this embodiment results in a flatter transfer characteristic (particularly in the range of 250 Hz to 16 kHz, with 250 Hz to 8 kHz being a more preferable range) than before correction.

<Additional Notes>
The device disclosed herein may, for example, be a single hardware entity that includes an input unit to which a keyboard or the like can be connected, an output unit to which an LCD display or the like can be connected, a communication unit to which a communication device (e.g., a communication cable) capable of communicating with an external device can be connected, a CPU (which may also include a central processing unit, cache memory, registers, etc.), RAM and ROM as memory, an external storage device such as a hard disk, and buses connecting these input unit, output unit, communication unit, CPU, RAM, ROM, and external storage device so that data can be exchanged between them. If necessary, the hardware entity may also be provided with a device (drive) capable of reading and writing recording media such as a CD-ROM. A physical entity equipped with such hardware resources includes a general-purpose computer.

The external storage device of the hardware entity stores the programs required to realize the above-mentioned functions and the data required to process these programs (this is not limited to an external storage device; for example, the programs may be stored in ROM, which is a read-only storage device). In addition, data obtained by processing these programs is stored appropriately in RAM, external storage device, etc.

In a hardware entity, each program stored in an external storage device (or ROM, etc.) and the data required to process each program are loaded into memory as needed, and interpreted, executed, and processed by the CPU as appropriate. As a result, the CPU realizes the specified functions (each component represented as a "... unit," "... means," etc., above).

The present disclosure is not limited to the above-described embodiments, and modifications may be made as appropriate without departing from the spirit of the present disclosure. Furthermore, the processes described in the above embodiments may not only be executed chronologically in the order described, but may also be executed in parallel or individually depending on the processing capacity of the device executing the processes or as needed.

As mentioned above, when the processing functions of the hardware entities (apparatuses of the present disclosure) described in the above embodiments are realized by a computer, the processing content of the functions that the hardware entities should have is described by a program. Then, by executing this program on a computer, the processing functions of the hardware entities are realized on the computer.

The various processes described above can be implemented by loading a program that executes each step of the above method into the recording unit 10020 of the computer 10000 shown in Figure 8, and operating the control unit 10010, input unit 10030, output unit 10040, etc.

The program describing this processing can be recorded on a computer-readable recording medium. Examples of computer-readable recording media include magnetic recording devices, optical disks, magneto-optical recording media, and semiconductor memory. Specifically, for example, magnetic recording devices include hard disk drives, flexible disks, and magnetic tapes; optical disks include DVDs (Digital Versatile Discs), DVD-RAMs (Random Access Memory), CD-ROMs (Compact Disc Read Only Memory), and CD-Rs (Recordable)/RWs (Rewritable); magneto-optical recording media include MOs (Magneto-Optical discs); and semiconductor memories include EEP-ROMs (Electrically Erasable and Programmable-Read Only Memory).

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. Furthermore, this program may be distributed by storing it in a storage device of a server computer and transferring it from the server computer to other computers via a network.

A computer that executes such a program, for example, first stores the program recorded on a portable recording medium or transferred from a server computer in its own storage device. Then, when executing a process, the computer reads the program stored on its own recording medium and executes the process in accordance with the read program. Alternatively, the computer may read the program directly from a portable recording medium and execute the process in accordance with the program. Furthermore, each time a program is transferred from a server computer to the computer, the computer may execute the process in accordance with the received program. Alternatively, the server computer may not transfer the program to the computer, but may instead execute the process through a so-called ASP (Application Service Provider) service, which realizes the processing function simply by issuing execution instructions and obtaining the results. In this embodiment, the program includes information used for processing by a computer that is equivalent to a program (such as data that does not directly instruct the computer but has properties that define computer processing).

In addition, in this form, a hardware entity is configured by executing a specified program on a computer, but at least part of these processing contents may also be realized by hardware.

Claims (4)

a display control unit that controls displaying the transfer characteristics from the speaker driver of the wearable open-ear speaker to the entrance of the ear canal in the form of a graphical equalizer;
an input receiving unit that determines correction equalizer parameters, which are parameters for correcting the transfer characteristics, based on a user input to the graphical equalizer;
a transfer characteristic correction device including an equalizer processing unit that executes equalization on an acoustic signal based on the correction equalizer parameters; 2. The transfer characteristic correction device according to claim 1,
a transfer characteristic measurement unit that measures a transfer characteristic based on an equalized acoustic signal;
The display control unit
A transfer characteristic correction device that executes control to display the measured transfer characteristic in the form of a graphical equalizer. A transfer characteristic correction method executed by a transfer characteristic correction device,
Executing a control that displays the transfer characteristics from the speaker driver of the wearable open-ear speaker to the entrance of the ear canal in the form of a graphical equalizer;
determining correction equalizer parameters, which are parameters for correcting the transfer characteristics, based on a user input to the graphical equalizer;
A transfer characteristic correction method comprising the step of performing equalization on an acoustic signal based on the correction equalizer parameters. A program that causes a computer to function as the transfer characteristic correction device described in claim 1.