JPH0376936B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a device for measuring the pitch of tinnitus sounds complained of by tinnitus patients, and more particularly to a tinnitus testing device that can accurately measure the frequency of tinnitus sounds.

[Prior art and its issues]

To effectively treat subjective tinnitus, first,
By quantitatively determining the nature of tinnitus as accurately as possible and capturing slight subjective fluctuations,
It is important to correctly evaluate the therapeutic effect. Unless tinnitus can be accurately measured, appropriate measures cannot be taken to treat tinnitus, nor can the effects of treatment or its progress be examined in detail. Tinnitus, like hearing loss, is a clinically important symptom of tinnitolaryngology. Hearing loss has undergone remarkable progress in recent years due to advances in audiology and balance neuroscience, as well as improvements in measurement methods brought about by advances in measuring instruments. However, various measurement devices are still used as substitutes for testing tinnitus, such as self-recording audiometers,
An audiometer (standard pure tone hearing test device) is used, and the reality is that the optimal diagnostic equipment has not necessarily been realized. Tinnitus testing equipment allows patients to easily distinguish the presentation frequency generated by the measuring device, and provides reproducible testing information such as the tinnitus center frequency (the tinnitus frequency that the patient feels loudest, hereinafter referred to simply as the tinnitus frequency). The degree to which tinnitus frequency (hereinafter referred to as tinnitus frequency) can be measured accurately is of paramount importance for the advancement of academic and medical treatment related to tinnitus. In the measurement of tinnitus, among the psychological factors of sound that make up tinnitus, which is a psychoacoustic phenomenon, the pitch, loudness, and timbre of the sound are measured. Among these three factors, measurement of pitch (tinnitus frequency) has become an important issue. However, the current situation is that there is no necessary and appropriate measuring device for this purpose. It is extremely difficult to explain tinnitus in words. This is because one patient describes the same sound as "shhh" and another patient describes it as "saa." To measure tinnitus frequency using an audiometer, the patient is asked to listen to a specific frequency of sound produced by the audiometer and compare it with the tinnitus sound.
That is, the pitch of the presented sound of a specific frequency and the tinnitus sound is compared. In this method, pure tones of 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz, 4000Hz, and 8000Hz are normally heard as the presented sounds. A self-recording audiometer that can be used as a substitute for measuring tinnitus frequency is disclosed in, for example, Japanese Patent Publication No. 34-9099 and Japanese Patent Application Laid-Open No. 11696-1982. However, self-recording audiometers are not designed to measure tinnitus frequency, and are used as a substitute because there is no suitable tinnitus frequency measuring device. With self-recording audiometers, the presentation frequency that the patient hears is continuously variable, so the more the presentation frequency is made to have a slight difference in frequency from the tinnitus frequency, the more the frequency discrimination ability of humans naturally reaches its limit. The disadvantage is that the measured values fluctuate. For this reason, it is difficult to generate a presentation frequency close to the tinnitus frequency using a self-recording audiometer. Even more troubling, some patients who complain of tinnitus have a decreased ability to distinguish between pitches of sounds by comparing the tinnitus frequency and the presentation frequency, that is, frequency discrimination ability. In the case of simultaneous comparison of two sounds, the frequency discrimination ability (relative frequency discrimination threshold) of normal people is reported to be 5 to 10%. Therefore, in order to accurately measure the tinnitus frequency of a patient with normal frequency discrimination ability, there is a gap between the presentation frequency and the tinnitus frequency, for example.
A frequency difference of 50-100Hz is required for 1000Hz. In tinnitus patients with poor frequency discrimination ability, in order to discriminate the difference between the presentation frequency and the tinnitus frequency,
A larger frequency difference is required. When measuring tinnitus frequency using a self-recording audiometer, if the frequency difference between the sound presented by the self-recording audiometer and the patient's tinnitus frequency is smaller than the patient's frequency discrimination ability, the difference between the tinnitus frequency and the presented frequency cannot be identified. In other words, it is not possible to distinguish whether the presentation frequency is higher or lower than the tinnitus frequency, and the tinnitus frequency cannot be measured accurately. This is because unless it can be determined whether the presentation frequency of the self-recording audiometer is higher or lower than the patient's own tinnitus frequency, the presentation frequency cannot be approximated to the tinnitus frequency. Musicians who have specially trained their ears remember the pitches of musical scales more accurately than the average person. However, even if a musician complains of tinnitus, when the presented frequency is continuously varied and listened to, the sounds as a whole do not have individual scale notes, so they feel like noise. Therefore, it is impossible to accurately distinguish between the pitch and the tinnitus frequency. Moreover, ordinary patients who have not specially trained their ears,
When the presented sound is continuously varied and compared to the tinnitus frequency,
The disadvantage is that the tinnitus frequency fluctuates each time a measurement is made, resulting in poor reproducibility. For this reason, even though self-recording audiometers can physically generate sound presentations that are accurately close to the tinnitus frequency, patients are unable to distinguish between the sound presentation sounds and their own tinnitus frequency because this device is continuously variable. do not have. As described above, various tinnitus testing devices have been used in the past, but the devices to date have been able to accurately measure the frequency of tinnitus sounds using simple and easy methods for all patients. The reality is that there is no such thing. In order to eliminate these drawbacks, the present invention reproduces sounds in accordance with the scale of music that almost everyone listens to on a daily basis, and compares sounds that match this scale with tinnitus. An important object of the present invention is that the tinnitus frequency can be easily and quickly measured by comparing the tinnitus frequency with a scale that is familiar and allows accurate identification of the pitch of the sound. Moreover, it is an object of the present invention to provide a tinnitus testing device that can accurately discriminate tinnitus.

[Means to solve conventional problems]

The tinnitus testing device of the present invention has the following configuration in order to solve the conventional problems. A tinnitus testing device is configured to be able to generate a plurality of sounds and to be able to adjust the intensity of the generated sounds so that the intensity of tinnitus can be measured. In addition, the tinnitus testing device of the present invention allows patients to easily and accurately compare the pitch of a sound by comparing pure tones of a scale equivalent to do-re-mi-fa-solacide, which patients are accustomed to hearing on a daily basis. Plays a sound that contains Huasoracid in its fundamental wave. Note that the tinnitus testing device of the present invention can adjust the frequency of the generated sound, so it goes without saying that it can also be used as a device for measuring the hearing limit of the ear.

[effect]

The tinnitus testing device of the present invention is preferably used in the following conditions. The side opposite to the ear where you feel tinnitus, or
Listen to the presentation sound in the ear on the same side. As the presentation sound, the students will hear the sound of "C" in each octave, which differs in pitch by one octave. That is, the presented sounds are: C "do"...65.4Hz, c "do"...130.8Hz, ^c1 "do"...261.6Hz, ^c2 "do"...523.3Hz, ^c3 "do"... ...1046.5Hz, c ⁴ "Do"...2093.0Hz, c ⁵ "Do"...4186.0Hz, c ⁶ "Do"...8372.2Hz. The patient is asked to listen to these sounds alternately for 2 to 3 seconds each, and is asked to say which presentation frequency the tinnitus frequency is close to, thereby determining which scale the tinnitus frequency is on. The intensity of the presented sound is about 5 dB higher than the minimum audible value. The sound pressure level is set to this level because the loudness level of tinnitus sound is often around this level. A patient who hears the presented sound simultaneously compares the tinnitus frequency and the presented frequency to compare the pitch of the sound. For example, a patient may have a tinnitus frequency of c ⁵ (do).
The answer is that it is lower than c ⁴ (do), higher than c 4 (do), and closer to c ⁴ (do) than c ⁵ (do). This method is called the rough petch method.
Match (abbreviated as RPM method). Next, c ⁴ of the presentation frequency obtained by the RPM method
Adjust the volume by adding 5 dB to the minimum audible value of each sound within a width of 1 to 1.5 octaves, centering on (C), and listen to the sounds of dore mihu asorasedo in order from low to high. The patient compares the presentation frequency of doremifaasolaside, which is a familiar pitch, with his or her own tinnitus frequency, and selects the sound that is closest to or matches the tinnitus. In this way, the tinnitus testing device of the present invention can easily and easily measure tinnitus frequencies from many patients with great precision and high reproducibility. The superior characteristics of this patient's tinnitus testing device become clearer when compared with previously published research papers on tinnitus. In this research paper, instead of the continuously variable reference sound of a self-recording audiometer, the reproducibility was measured by listening to a presentation sound with a stepwise frequency change of 0.1 pitch after 10 minutes. According to the results of this study, it has been reported that under these conditions, the reproducibility of the results of measuring the tinnitus frequency of patients whose subjective tinnitus does not change is only 50%, which is not good. In other words, even if the measurement is taken 10 minutes later, the probability of observing the same tinnitus frequency as the previous measurement is half that. The presentation sound of 0.1 pitch is
10 whose frequency is a geometric series within one octave
This was used as the reference tone. In contrast, when the tinnitus testing device of the present invention was used to measure the tinnitus frequency of the same patient who did not subjectively complain of fluctuations in tinnitus sound, the tinnitus frequency was measured twice in the morning and afternoon, that is, after 6 hours. was measured again and achieved an excellent reproducibility of 60%. That is, the device of the present invention was able to achieve higher reproducibility even though the time interval for measuring tinnitus frequencies was extremely long, from the aforementioned 10 minutes to 6 hours. This is because the patient memorizes the presentation sound of "dore mi fa asoracido", which he has been accustomed to hearing since childhood, as a specific scale, and has a high ability to discriminate the frequency of this sound. By the way, the frequency of do-re-mi-fa-so-racido is 0.122 pitch for a whole tone and 0.059 pitch for a semitone, which is physically almost no difference from the reference tone of 0.1 pitch mentioned above. The device of this invention has 0.1
Even though it is almost the same as the pitch sound, tinnitus frequency can be measured with high measurement accuracy and high reproducibility. This is because the patient memorizes the scale of "dore mihu asoracido" as a specific scale in the brain, and furthermore,
High reproducibility is achieved through a psychoacoustic phenomenon called ``tonality'' of ``DoReMihuaSoracido''. Furthermore, the inventor has determined that after 7 days from the first measurement, taking into account the minimum unit width of the measurement device scale, 7
When we measured the tinnitus frequency of the same patient whose tinnitus sound had not changed subjectively the previous day, we achieved a high reproducibility of 94.8%. In this measurement, taking the minimum unit width into consideration is a measurement method in which sounds that differ by one note or a semitone depending on the part are considered to be the same note. For example, for the sound "hua", 1
The high-pitched "G" sound and the semitone-low "Mi" sound are the same sound. As described above, the reason why the tinnitus testing device of the present invention achieves high accuracy and high reproducibility is as follows. Use the standard tone (note name) of the do-re-mi-fa-solacide scale, which is the most familiar since childhood. One octave is subdivided into seven parts. Each note in Do Re Mi has a psychoacoustic phenomenon called tonality that gives it a unique individuality, and due to this phenomenon, even though one octave is subdivided into seven It has the advantage that patients can easily distinguish the difference between their own tinnitus frequency and the presented frequency. Tonality is a technical term in music theory.When listening to music, in addition to the feeling of pitch that changes continuously according to changes in frequency (Mel scale expression), for example, tonality is a term used in music theory. It means a phenomenon in which each note on the scale has its own unique personality. The pitch of a sound that changes in a mel-like manner can be expressed one-dimensionally on the spiral curve drawn on the surface of the bell shown in Figure 3, while the feeling of tonality can be expressed in a bell-shaped three-dimensional space. For example, the difference between two notes in the second interval, such as "Ha" and "D", is because the frequencies are close to each other and narrow, and physically there is little difference in pitch between them. Physically, it feels farther away than the difference between two perfect eighth notes, which are twice as far apart in frequency, such as "c", which is one octave higher. In other words, due to a psychoacoustic phenomenon called tonality, the human ear, in a very mysterious way, hears sounds that are adjacent to each other in each scale and have close frequencies than sounds that are an octave higher and have twice the frequency. Can be heard with a distant feel (octave proximity). It is "Dore Mihua Soracide"
This is because the brain clearly remembers the unique feeling of each sound. The tonality phenomenon significantly improves the measurement accuracy of the tinnitus testing device of the present invention. This is because tinnitus patients memorize each unique sound of the scale name due to the tonality phenomenon, and compare the memorized presentation sound with the tinnitus frequency to determine the difference in pitch. Therefore, the tinnitus testing device of the present invention can measure the tinnitus frequency of many patients simply and easily, and with high accuracy and reproducibility. Furthermore, a noteworthy feature of the tinnitus testing device of the present invention is that anyone can accurately measure tinnitus frequencies with little practice.
This is something that tinnitus patients are used to hearing on a regular basis.
“Do-Re-Mi-Huasor-A-Sora-Sido” is a unique sound.
The reason is that the name of the pitch is used as the presentation sound. Self-recording audiometers that continuously change the presentation frequency for the patient to hear typically require repeated practice to improve reproducibility. However, no matter how much you practice, you cannot expect reliable measurements with high reproducibility. The reason is that the continuously variable presentation frequency does not have any individuality.
It is not possible to select a specific frequency as a measurement value, and only measurement values with a range can be obtained, such as 200 to 400Hz, 3500 to 4000Hz, or 300 to 700Hz, which does not result in accurate measurement values. . Furthermore, since the presentation frequency of the self-recording audiometer is an unfamiliar reference sound, the learning effect is also extremely low. For this reason, with a self-recording audiometer, excellent reproducibility cannot be expected no matter how many times you practice. However, the scale of "do-re-mi-fa-a-so-la-cido" generated by the tinnitus testing device of the present invention is a sound that everyone is familiar with since childhood. In other words, most people, from infants to the elderly, listen to everyday music and memorize the scales of dore mihu asorashido.
You are training your own frequency discrimination ability without realizing it. Therefore, the tinnitus testing device of the present invention has the feature that anyone can measure the tinnitus frequency with high reproducibility and accuracy with little practice.

[Preferred embodiment]

Embodiments of the present invention will be described below based on the drawings. However, the embodiments shown below are illustrative of a device for embodying the technical idea of this invention, and
The device of the present invention does not limit the material, shape, structure, and arrangement of the component parts to the following structures. Various modifications may be made to the device of the present invention within the scope of the claims. The tinnitus testing device shown in Figure 1 consists of a voltage controlled oscillator VCO1 whose oscillation frequency is controlled by the input voltage and the capacitance of the connected capacitor;
It is equipped with an amplifier 3 that amplifies the output signal of the VCO 1 and generates sound with a sound generator 2 such as a speaker, earphone, headphone, etc., and a switch circuit that controls the input voltage of the VCO 1 and switches the connected capacitor of the VCO 1. . VCO1 changes the oscillation frequency by switching the capacitor. Therefore, seven capacitors C are connected to VCO1 via rotary switch 5.
1, C2, C3, C4, C5, C6, and C7 are connected. The capacitor is switched from one with a large capacitance to one with a small capacitance, oscillating a sound of one octave, or twice the frequency. Also, this
The oscillation frequency of VCO1 increases in proportion to the input voltage from the voltage dividing resistor. The switch circuit includes a rotary switch 5 for switching the capacitor and seven changeover switches 4. The change-over switch 4 switches the input voltage of the VCO 1 to generate the sound of do-re-mi-fa-solacide. The changeover switch 4 is connected to a voltage dividing resistor 6. 7 capacitors C1, C2, C3, C4, C
5, C6, C7 are connected together on one side,
It is connected to the capacitor terminal of the VCO 1, and the other end is connected to the fixed contact of the rotary switch 5. For VCO1, when the capacitance of the connected capacitor becomes 1/2, the oscillation frequency doubles. Therefore, the seven capacitors are adjusted so that, for example, the capacitance becomes 1/2. For example, the capacitance of each capacitor is determined as follows: C1 = 0.064μF, C2 = 0.032μF, C3 = 0.016μF, C4 = 0.008μF, C5 = 0.004μF, C6 = 0.002μF, C7 = 0.001μF. . The rotary switch 5 has a movable contact that is grounded, and connects one of the capacitors to the ground to switch the oscillation frequency in octave units. For example, by switching the movable contacts of the rotary switch 5, C, c, c ¹ , c ² , c ³ , c ⁴ ,
c ^{The 5} tones of the scale are generated in sequence. The voltage dividing resistor 6 is determined so that when any of the changeover switches is turned on, a predetermined voltage is applied to the VCO 1 to control the VCO 1 and the oscillation frequency. For example, capacitor C1 with maximum capacitance
is grounded by the rotary switch 5, and as the changeover switches 4 are pressed in order from the top,
VCO1 emits 65.406Hz (C), 73.416Hz (R), 82.407Hz (Mi), 87.307Hz (F), 97.999Hz (S), 110.00Hz (A), 123.47Hz (S), and all switches It is determined that when the is turned off, a sound of 130.81Hz (C) is generated. Although not shown, the changeover switch has a mechanism in which when any one of the switches is pressed and turned on, all the other switches are turned off. The amplifier 3 is for amplifying the output signal of the VCO 1 to, for example, a maximum output of about 0.1 mW to 10 W, and includes an attenuator (not shown) that can adjust the output signal level preferably within a range of 100 dB. As shown by the chain lines in Figure 1, two sets of VCO1,
A device that extracts two types of signals at 1A, mixes them, and reproduces them can reproduce signals that include harmonics or subharmonics in the fundamental wave. In this case, the rotary switch 5 for changing the capacitor has two
A rotary switch 5 with circuit 7 contacts is used,
Switch both capacitors together. The capacitors connected to VCO1A for harmonic or subharmonic generation are capacitors C1 to C7 for fundamental wave generation.
is determined to be an integer fraction of . FIG. 2 shows a tinnitus testing device that generates a required scale signal in digital form, converts it into a D/A, and reproduces an analog signal. This inspection device includes a keyboard 7 for operation, a CPU 9 to which the keyboard 7 is connected via an interface I/O 8, a ROM 10 which is a memory connected to the CPU 9, and D/A conversion of the output signal of the CPU 9. D/A converter 11 and D/A
An amplifier 3 that amplifies the output of the converter 11, and a sound generator 2 that converts the electrical signal of the amplifier 3 into mechanical vibration.
It is equipped with The ROM 10 stores information that causes the CPU 9 to output a predetermined digital signal in response to an input signal from the keyboard 7. For example, from the keyboard
When there is an input signal of c ¹ , the CPU 9 sends the information to the ROM 1 to output a signal in which the analog signal after D/A conversion is a pure tone of 261.63Hz or this is the fundamental wave.
It is stored as 0. The ROM 10 also stores information for controlling the analog signal level after D/A conversion through input from the keyboard. By the way, in the apparatus of the present invention, the reproduced sound is reproduced based on do-re-mi-fa-a-solacide, but it goes without saying that the pitch of the reproduced sound, that is, the frequency, is slightly shifted.

[Brief explanation of drawings]

1 and 2 are block diagrams of a tinnitus testing device showing an embodiment of the present invention, and FIG. 3 is a graph showing tonality. 1...VCO, 2...Sound generator, 3...Amplifier,
4... Selector switch, 5... Rotary switch, 6... Voltage division resistor, 7... Keyboard, 8...
I/O, 9...CPU, 10...ROM, 11...
D/A converter.

Claims (1)

[Claims] 1. In a tinnitus testing device configured to be able to generate a plurality of sounds and to adjust the intensity of the generated sounds, the generated sound is a pure tone corresponding to do-re-mi-fa-a-solacide;
Alternatively, a tinnitus testing device characterized in that the sound includes dore mifa asolaside in its fundamental wave.