JPS6254280B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an artificial ear for quickly calibrating a hearing aid used by a hearing-impaired person.

There are four types of conventional artificial ears shown in FIG. 1 (a) to (d).

(a) Microphone 3 is placed at the eardrum at the back of the ear canal 2.
buried.

(b) The back of the ear canal 2 is made into a non-reflective end with sound absorbing material 4, etc.

(c) A membrane-shaped acoustic resistor 5 made of nonwoven fabric or the like is provided at the eardrum position at the back of the ear canal 2.

(d) A so-called Zwislocki type acoustic impedance element 7 corresponding to the eardrum impedance is provided at the back of the ear canal 2.

In the example shown in Figure 1a above, the microphone 3 is placed at the position of the eardrum at the back of the external auditory canal 2 connected to the pinna 1. It is not possible to achieve the same acoustic impedance with the current technology.

In the example shown in FIG. 1b, the sound absorbing material 4
Although the microphone 3 is placed on the side, the inside of the ear canal 2 forms a traveling wave sound field, and the natural resonance of the ear canal 2 is eliminated.

Here, as a quantity representing the acoustic characteristics of the ear, we take the ratio of the sound pressure on the eardrum (the sound pressure at the microphone part in the case of an artificial ear) and the sound pressure at the entrance of the ear canal, and this is called the transfer function.

The transfer function of this conventional example with the configuration shown in Fig. 1 a, b is significantly different from the transfer function of the real ear (indicated by diagonal lines) as shown in Fig. 2 a, b, and is not suitable for use as an artificial ear for calibrating hearing aids. It was an inappropriate method that could not be used unless a calibration means and a correction means were used together.

Furthermore, in the example shown in FIG. 1c, the inner part of the external auditory canal 2
In the example shown in FIG. 1d, a microphone 3 is placed deep inside the ear canal 2 via a twist-type acoustic impedance element 7. , the transfer function with the configuration shown in Fig. 1 c, d is shown in Fig. 2 c, d
As shown in , it is possible to match the transfer function of the real ear (indicated by diagonal lines) to an extent that causes no practical problems. However, in the example shown in FIG. 1c, a membrane-shaped acoustic resistor 5 imitating the eardrum is provided at the position of the eardrum of the real ear, and the transmission in the real ear is achieved by balancing the stiffness of the cavity 6 deeper than the pseudo eardrum. Since the characteristics are matched to a function, the material of the acoustic resistor 5 and the size of the cavity 6 are important factors in determining the characteristics. This membrane-type acoustic resistor 5 is made of a non-woven fabric or the like with fine ventilation holes, and it is difficult to make one with uniform characteristics.Furthermore, when the acoustic resistor 5 is vibrated by sound waves, it is difficult to create a membrane with fine ventilation holes. is attached to the acoustic resistor 5 and causes clogging of the ventilation holes, so that the transfer function changes with use, making it impractical.

In the example of FIG. 1d, the acoustic impedance element 7
is a diameter of 0.4 that connects multiple cavities and external auditory canal 2.
Since it is composed of ~0.7 mm thin tubes, the structure is complex, and as in the example in Figure 1 c, the transfer function is likely to deteriorate due to dirt entering and adhering to the thin tubes, so this can be prevented. In order to do so, it required disassembly, cleaning, and adjustment each time it was used, making it unsuitable for practical use.

An object of the present invention is to provide an artificial ear for hearing aid calibration which eliminates the drawbacks of the prior art described above, has a simple structure, provides a stable transfer function, and is easy to use.

For this reason, the invention is an artificial ear that is configured to match the transfer function of a real ear by connecting an acoustic tube with a diameter different from the diameter of the ear canal to the end of the ear canal. It can be used without adjustment or maintenance without using an acoustic impedance element.

This invention will be explained below along with examples.

In FIG. 3, reference numeral 11 denotes a pseudo-head, and the auricle 1 is integrally formed on the outer circumference of this pseudo-head 11. 2 is an external auditory canal formed in the pseudo head 11 via the auricle 1; 3 is a microphone attached to the side surface near the end of the external auditory canal 2;
An acoustic tube 8 having a diameter smaller than the diameter of is connected. End portion 9 of acoustic tube 8 that is not connected to external auditory canal 2
is an open end.

In this configuration, the ear canal 2 has a diameter of 7 to 8 mm and a length of 20 to 25 mm, and the acoustic tube 8 has a diameter of 3 to 5 mm and a length of about 4 m. A so-called vinyl tube was used as the acoustic tube 8, and the inside of the pseudo head 11 was housed by winding it into a spiral shape.

The transfer function of the artificial ear configured in this way is
As shown in Figure e, the actual ear characteristics fall within the range of variation among people (within the diagonal lines).

As mentioned above, the structure of the present invention is a simple one in which two pipes of different diameters are connected in series.
A stable transfer function can be obtained without being adversely affected by dust that causes clogging in conventional products. Additionally, since it has a robust structure without a vibrating membrane, it is easier to handle than conventional products.

In another embodiment shown in FIG. 4, a joint tube 10 whose cross-sectional area gradually changes is used to connect the external auditory canal 2 and the acoustic tube 8.
The above-mentioned effects were the same in this configuration as well.

Furthermore, even when the joint between the external auditory canal 2 and the acoustic tube 8 was made into a fitting structure as shown in FIG. 5, there was no substantial change in the characteristics.

Further, the length of the sound tube 8 is 3 at the end 9 of the sound tube 8.
In the case of m or more, no difference was observed in the characteristics between open end and closed end. If the length of the sound tube 8 is less than 3 m, there will be a difference in the characteristics, but there is no problem in practical use as long as it is within the range of variations in the characteristics of the real ear.

Therefore, according to the present invention, there is no need for anything such as a diaphragm having minute ventilation holes or an acoustic impedance circuit consisting of a combination of pores and cavities, but a simple structure consisting of two tubes connected in series. With this configuration, an easy-to-use artificial ear can be obtained.

Now, this artificial ear is attached to a pseudo head 11, but it is clear that without the pseudo head 11, the same effect as a conventional artificial ear with only an ear part called an acoustic coupler can be obtained. The presence of the pseudo head 11 makes it possible to calibrate hearing aids such as behind-the-ear hearing aids, glasses-type hearing aids, pinna-in-the-auricular hearing aids, etc., in which the diffraction effect of the human head, the binaural effect, etc. are problematic. If the auricle 1 has a replaceable structure, it becomes possible to correct individual differences in the auricle 1. Furthermore, if the pseudo head 11 equipped with the artificial ears is attached to a pseudo torso having a shape similar to the external shape of the human body, a hearing aid that can be used by attaching the microphone part of the hearing aid to a chest pocket of clothes, etc. Also, due to the diffraction effect of the human body,
It can be applied to correction calibration due to the buff-full effect, etc.

[Brief explanation of the drawing]

Figures 1 a to d are structural diagrams of the conventional structure, Figure 2 is a transfer function characteristic diagram, Figure 3 is a structural diagram of one embodiment of the present invention, Figure 4 is a structural diagram of another embodiment of the present invention, 5
The figure is a structural diagram of still another embodiment of the present invention. Explanation of symbols 1...Auricle, 2...Earth canal, 3...Microphone, 8...Acoustic tube, 9...End of acoustic tube, 10
...Connecting tube, 11...Pseudo head.

Claims (1)

[Claims] 1. An artificial ear having a tube corresponding to the external auditory canal, characterized in that an acoustic tube having a diameter smaller than the diameter of the external auditory canal is connected to the end of the external auditory canal, and a microphone is provided on the side of the external auditory canal. artificial ear. 2. The artificial ear according to claim 1, wherein the cross-sectional area of the joint between the external auditory canal and the acoustic tube is gradually changed. 3. The artificial ear according to claim 1 or 2, wherein the artificial ear is formed inside the pseudo head via an auricle formed on the outer periphery of the pseudo head, which is equivalent to a human head. 4. The artificial ear according to claim 3, wherein the pseudo head is attached to a pseudo torso having an outer shape equivalent to that of a human body.