KR100708207B1 - Method for compensating frequency characteristics and apparatus therefor - Google Patents

Abstract

The present invention relates to a method for compensating for frequency response characteristics, and more particularly, to a method for compensating for frequency response characteristics of a portable device according to the degree of closeness. The present invention stores the sound pressure measured according to the change in the pressure applied to the ear in a database, measures the degree of adhesion, which is the extent to which the portable device adheres to the ear, and predicts the frequency response characteristics according to the degree of adhesion based on the stored database. By compensating for the frequency response of the signal output from the portable device by comparing the predicted frequency response with the reference frequency response, which is the ideal frequency response, You can compensate.

Frequency, compensation, tightness, pressure, sound pressure

Description

Frequency response characteristic compensation method and apparatus therefor {Method for compensating frequency characteristics and apparatus therefor}

1 is a diagram illustrating a conceptual diagram of a frequency response characteristic compensation device according to the present invention.

2 is a view showing a position in the ear where sound pressure measurement can be made.

3 is a view illustrating an embodiment of a sound pressure measurement equipment.

FIG. 4 is a diagram illustrating an embodiment of a frequency response characteristic obtained by the sound pressure measuring apparatus of FIG. 3.

5 is a view showing for explaining the adhesion measuring unit according to the present invention.

6 is a diagram illustrating a reference frequency response characteristic according to the present invention.

7 illustrates one embodiment of a base enhancement / reduction filter.

8 is a flowchart illustrating a frequency response characteristic compensation method according to the present invention.

The present invention relates to a method and apparatus for compensating for frequency response characteristics, and more particularly, to a method and apparatus for compensating for frequency response characteristics of a portable device according to the degree of closeness.

As portable devices become widespread, many people are using earphones, headphones, and mobile phones. Accordingly, there is an increasing demand for improving the quality of sound output from portable devices. As a method for improving the sound quality, there is a technique for correcting the frequency response characteristics of the output sound signal.

The conventional frequency response characteristic correction method is to output a signal close to the set frequency response characteristic by adjusting the intensity of the signal level of a specific band of the sound signal output based on the preset correction data. However, such a correction method has a problem in that the user's use state is not considered when the frequency response characteristic is corrected.

For example, when the portable device is closer to the user's ear, the low range signal is strengthened and when the portable device is farther away from the user's ear, the high range signal is strengthened. There was a problem that does not have an improvement effect of quality.

An object of the present invention is to measure how close the portable device is to the user's ear, and to compensate for the frequency response characteristic by comparing the frequency response characteristic and the ideal frequency response characteristic predicted according to the degree of closeness, thereby the frequency of the portable device sound signal. The present invention provides a frequency response characteristic compensation method and apparatus for appropriately compensating a response characteristic according to a user's use state.

A feature of the present invention for achieving the above object is a frequency response characteristic compensation apparatus, comprising: a database in which a sound pressure measured according to a change in pressure applied to the ear is stored; An adhesion measurement unit for measuring a degree of adhesion of the portable device to the ear; A frequency response characteristic predictor for predicting a frequency response characteristic of a sound signal output from the portable device based on the database and the measured degree of adhesion; And a frequency response characteristic compensator for compensating the predicted frequency response characteristic by comparing the predicted frequency response characteristic with a reference frequency response characteristic which is an ideal frequency response characteristic.

Preferably, the adhesion measure includes a pressure sensor or a force (Force) sensor.

Preferably, the database is characterized in that the sound pressure measured at the drum reference point (drum reference point) in accordance with the change in the pressure applied to the ear is stored.

Preferably, the frequency response characteristic compensator includes a base enhancement / reduction filter, which is one or more digital filters, an FIR filter, an IIR filter, or one or more analog filters.

According to another aspect of the present invention, there is provided a frequency response characteristic compensation method comprising: storing a sound pressure measured in accordance with a change in pressure applied to an ear in a database; Measuring the degree of adhesion, which is the extent to which the portable device is in close contact with the ear; Predicting a frequency response characteristic of a sound signal output from the portable device based on the database and the measured degree of adhesion; And compensating the predicted frequency response characteristic by comparing the predicted frequency response characteristic with a reference frequency response characteristic which is an ideal frequency response characteristic.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a conceptual diagram of a frequency response characteristic compensation device according to the present invention.

Referring to FIG. 1, the apparatus for compensating frequency response characteristics according to the present invention includes a database 102, an adhesion measure 104, a frequency response characteristic predictor 106, and a frequency response characteristic compensator 108. .

The database 102 stores the sound pressure measured at the drum reference point as the pressure applied to the ear changes.

Hereinafter, a process of generating the database 102 will be described with reference to FIGS. 2 to 4.

2 is a view showing a position in the ear where sound pressure measurement can be made.

Referring to FIG. 2, when the sound pressure measurement is performed to generate the database 102, the measurement position includes an ear reference point (ERP), an ear entrance point (EEP), and an ear tympanic position ( Drum Reference Point (DRP). In the present invention, the sound pressure is measured and used in the eardrum. In general, when the sound pressure is measured at the eardrum position of the eardrum, the sound pressure in the 1 to 3kHZ band is caused by the resonance of the ear canal and ear kernel. The phenomenon of abnormal reinforcement will appear. However, the position for measuring the sound pressure is not limited to the eardrum position of the ear, it is possible to measure at various positions other than the start point of the inlet and ear hole of the ear described above.

3 is a view illustrating an embodiment of a sound pressure measurement equipment. Using the sound pressure measurement equipment 302 of FIG. 3, it is easy to obtain the pressure applied to the artificial ear 304. In addition, it is also easy to measure the change in the sound pressure in the ear tympanic membrane according to the pressure change while changing the pressure applied to the artificial ear 304. Through this measurement, the measured value of the sound pressure according to the pressure applied to the ear is obtained, and the frequency response characteristic thus obtained is stored in the database 102.

FIG. 4 is a diagram illustrating an embodiment of a frequency response characteristic obtained by the sound pressure measuring apparatus of FIG. 3. Referring to Figure 4 it can be seen that the shape of the frequency response characteristic curve changes as the pressure applied to the ear from 1N to 10N (402 to 412). That is, it can be seen that as the pressure applied to the ear increases, the sound pressure in the band of 1 kHz or less increases. However, such a change in frequency response may occur due to the material of the device in close contact, that is, a difference between a rubber material and a plastic material. However, a factor mainly affecting the frequency response property is the degree of pressure applied to the ear as shown in FIG. 4. That is, adhesiveness becomes.

In this case, dBSPL indicated in units of sound pressure in FIG. 4 will be described. First, SPL in dBSPL stands for “Sound Pressure Level,” and all the sounds we hear are caused by the pressure of air molecules (Molecules) in the atmosphere, which can be expressed in terms of power. dBSPL is the reference index of 0.0002 microbars (Threshold of Hearing) when the smallest sound level that humans can hear in the air is 0.0002 microbars (= 0.0002 dyne / cm² = 0.00002 Newtons / m² = 20 × 10-6Pa). The absolute ratio for That is, dBSPL is a unit expressing sound intensity in absolute value, whereas dB is a unit expressing sound intensity relatively.

The adhesion measurement unit 104 measures the degree to which the portable device is in close contact with the ear.

5 is a view showing for explaining the adhesion measuring unit according to the present invention.

Referring to FIG. 5, in the present invention, a pressure sensor or a force sensor is used to measure the degree to which the portable device is in close contact with the ear. That is, the adhesion measurement unit detects how closely the user's ear is connected to the portable device by using one or more pressure sensors or force sensors mounted on the hydration unit 502 of the portable device 500, and the value is the closest pressure. Quantize However, as a method of measuring the degree of adhesion, there is a method using a distance sensor and a temperature sensor in addition to using such a pressure sensor.

The method using the distance sensor is a method in which the distance sensor is mounted on the receiver 502 of the portable device 500 to compensate with the optimum frequency response characteristic according to the actual distance between the portable device and the user's ear through the distance sensor. In addition, the method using the temperature sensor is a method of mounting a temperature sensor on the receiver 502 of the portable device 500 to compensate with the optimum frequency response characteristics according to the temperature proportional to the actual distance between the portable device and the user's ear. .

As such, the degree of adhesion may be measured using a method using pressure, temperature, distance, or the like, and may be measured by combining a plurality of methods depending on the embodiment.

The portable device includes all devices that can be carried in the ear, such as earphones, headphones, home cordless phones, mobile phones, and the like.

The frequency response characteristic predicting unit 106 refers to the frequency response characteristic stored in the database 102 and predicts the frequency response characteristic of the signal output from the portable device according to the pressure measured by the adhesion measure unit 104. . However, as described above, the degree of adhesion can be measured using temperature, distance, etc. in addition to pressure.

Referring to FIG. 4, when the pressure applied to the ear by the adhesion measure unit 104 is 1 N, the frequency response characteristic is predicted in the form of 402.

The frequency response characteristic compensation unit 108 compensates the predicted frequency response characteristic by comparing the predicted frequency response characteristic with a reference frequency response characteristic which is an ideal frequency response characteristic.

6 is a diagram illustrating a reference frequency response characteristic according to the present invention.

In general, the reference frequency response signal is divided into a free field characteristic and a diffuse field characteristic, and an appropriate response characteristic may be used as the reference frequency response characteristic according to the purpose. However, in the case of a portable device, that is, an earphone, a headphone, a mobile phone, etc., the case of showing the characteristics of the diffuse field is regarded as a desirable frequency response characteristic. If the sound pressure measured at the ear's eardrum exhibits a diffuse field characteristic, the user will feel a flat frequency response, as if listening in a listening room with an appropriate diffuse field. Therefore, in the present invention, the frequency response characteristic having the diffuse field characteristic is used as the reference frequency response characteristic, which is illustrated in FIG. 6. Referring to FIG. 6, sound pressures from 2 kHz to 3 kHz are further enhanced compared to other frequency bands, and this characteristic becomes a frequency response characteristic with a diffuse field characteristic.

For example, the frequency response characteristic compensation unit 108 compares the frequency response characteristic predicted from FIG. 4 with the reference frequency response characteristic of FIG. 6 to compensate for the predicted frequency response characteristic of FIG. 4.

In order to compensate for this, a frequency compensation filter is required. The frequency compensation filter may be configured as a digital filter, an FIR filter IIR filter, or a base enhancement / reduction filter when only an analog output is supported.

7 illustrates one embodiment of a base enhancement / reduction filter.

Referring to FIG. 7, when the low bass is to be enhanced, compensation is possible using the graph of 702, and when the low bass is to be reduced, the compensation is possible using the graph of 704.

8 is a flowchart illustrating a frequency response characteristic compensation method.

 In step 802, the sound pressure measured according to the change in pressure applied to the ear is stored in the database.

In step 804, the degree of adhesion, which is the degree to which the portable device is in close contact with the ear, is measured.

In step 806, the frequency response characteristic of the sound signal output from the portable device is predicted based on the database and the measured adhesion.

In operation 808, the predicted frequency response characteristic is compensated by comparing the predicted frequency response characteristic with a reference frequency response characteristic, which is an ideal frequency response characteristic.

Meanwhile, the above-described embodiments of the present invention can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium.

The computer-readable recording medium may be a magnetic storage medium (for example, a ROM, a floppy disk, a hard disk, etc.), an optical reading medium (for example, a CD-ROM, a DVD, etc.) and a carrier wave (for example, the Internet). Storage medium).

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

The present invention measures how close the portable device is to the user's ear, and compares the frequency response characteristic and the ideal frequency response characteristic predicted according to the degree of closeness to compensate for the frequency response characteristic, whereby the frequency response characteristic of the portable device sound signal This has the effect of properly compensating according to the user's use state.

Claims (5)

In the frequency response characteristic compensation device, A database in which a sound pressure measured according to a change in pressure applied to the ear is stored; An adhesion measurement unit for measuring a degree of adhesion of the portable device to the ear; A frequency response characteristic predictor for predicting a frequency response characteristic of a sound signal output from the portable device based on the database and the measured degree of adhesion; And And a frequency response characteristic compensator for compensating the predicted frequency response characteristic by comparing the predicted frequency response characteristic with a reference frequency response characteristic which is an ideal frequency response characteristic. The method of claim 1, The adhesion measurer measures the adhesion using a pressure sensor or a force sensor and quantizes the measured value to the closest pressure. The method of claim 1, And said database stores sound pressure measured at a drum reference point according to a change in pressure applied to the ear. The method of claim 1, And the frequency response characteristic compensator includes a base enhancement / reduction filter, which is one or more digital filters, an FIR filter, an IIR filter, or one or more analog filters. In the frequency response characteristic compensation method, Measuring the degree of adhesion, which is the extent to which the portable device is in close contact with the ear; Predicting a frequency response characteristic of a sound signal output from the portable device based on a database in which the sound pressure measured according to the pressure applied to the ear is stored and the measured degree of adhesion; And Compensating for the predicted frequency response characteristic by comparing the predicted frequency response characteristic with a reference frequency response characteristic that is an ideal frequency response characteristic.

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