Why do hearing aids need to be fitted with both ears? —Jinghao medical hearing

Why do hearing aids need to be fitted with both ears? —Jinghao medical hearing

Hearing aids can help patients to use residual hearing to compensate for lost hearing. As a rehabilitation tool, the first thing is to hear more clearly, followed by noise reduction, gain, balance function, etc., to protect residual hearing, slow down hearing loss, and others. Better communication.

From a physiological point of view, the human body is not a symmetrical structure, and the hearing of the two ears will be different. Especially when the hearing of both ears is declining, the degree of damage is often different. Then, can I just have a hearing aid with one ear? Of course not, let Xiaobian tell you the advantages of binaural fitting.

One: binaural sound source localization and noise reduction

1, sound source localization

Sound source localization is the judgment of the auditory system on the position of the sounding object. It includes horizontal sound source localization and vertical sound source localization and recognition of the distance from the listener. The balance of binaural hearing balance is one of the decisive factors in the ability of human sound source to locate. Just as you can’t judge the distance of an object when you observe an object with one eye, there is no way to accurately determine the position of the sound source. Therefore, if the hearing damage of the two ears is different, and only the hearing aid is worn on the severe side ear, the sound from any direction will be heard by the side with the better hearing threshold, and the direction of the sound source cannot be judged.

2, suppress noise

The auditory system is a good noise reduction system. The signal-to-noise ratio of the signals received by the ears is higher than that of the single-sided ear, which means that the ears can reduce the noise more effectively than the single ear, and hear more clearly in the noise; two ears When receiving the same signal, there will be a small time difference and phase difference, and the brain can use these differences to discern the sound you want to hear and ignore the noise.

Two: the interaction of the ears

1, integration effect

The sound signals transmitted into the ears are transmitted to the auditory center through the auditory nerves on both sides, and the bilateral cerebral cortex integrates the signals to respond accordingly. Studies have shown that binaural hearing can achieve 3dB gain more than single ear hearing. Since the binaural wear can improve the integration effect, especially the energy integration of the low-frequency sound is reduced, and the overall output gain of the hearing aid can be reduced, the outer casing or the ear mold of the hearing aid can be made loose and ventilated under the condition of permission. Increase, leave as much space as possible inside the ear canal to reduce the troubles caused by the ear plugging effect. For patients with binaural poisoning and extreme hearing impairment, this integration and accumulation effect is more important.

2, auditory fusion

The sounds of thousands of sound sources in nature are lingering around people. Different sounds have different frequencies and intensities. These confusing sounds are transmitted from different directions to both ears. The frequency and intensity of sound heard by each ear are Differently, through the auditory fusion effect, it can effectively integrate the different sounds transmitted to the ears, making them merge into a sound, improving the stereoscopic sound and sound quality of the sound.

Three: avoiding cephalometric effects and hearing deprivation

1, avoiding cephalometric effects

The sound intensity of the ears is different because of the position of the sound source. When the sound is emitted from the left side, the sound heard by the left ear is significantly larger than that of the right ear. This phenomenon is the avatar effect, which is due to the head. Produced by the barrier function of the Ministry.

If the hearing loss of a patient’s ears is asymmetrical, when the sound comes from the direction of the ear with poor hearing, the ear with the better hearing will be directed towards the sound source. Similarly, if both ears have hearing loss (symmetric or asymmetrical) This is also the case when only one ear is worn when the hearing aid is selected. Because when the sound source comes from the other side of the ear, the head can hinder and attenuate the transmission of sound waves, especially for high-frequency sounds higher than 2000Hz, the attenuation can reach 10~17dB. This will greatly reduce the clarity of the hearing aid. A patient with a large number of single-sided options can be very difficult to hear when listening to the sound from the side ear, often with the hearing ear wearing the ear facing the other side. If the patient chooses to wear both ears, it will solve the cephalometric effect, and there will be no squeaking of the sounds of the ears, and it is easy to listen to sounds from multiple directions.

2, avoiding hearing deprivation

Hearing deprivation refers to the long-term compensation of one ear for patients with bilateral symmetrical hearing loss, and the speech recognition rate of uncompensated ear will progressively decrease with time. The occurrence of this phenomenon is related to the long-term acceptance of asymmetric sound stimulation and unequal information input by both ears. When the patient’s ear receives hearing aid, relatively more sound information can be obtained, and the hearing aid ear can not be fully stimulated by the sound, and the signal transmitted from the cochlea to the central auditory system is weak, so it is suppressed by the hearing aid. The brain that has been around for a long time seems to give up the information that is not heard from the ear, resulting in an auditory deprivation effect. The auditory deprivation phenomenon will recover to a certain degree after the hearing aid has not been properly compensated for a period of time, and some can even recover to the initial level.

Head shadow effect and auditory deprivation

Many patients in the fitting of hearing aids (both ears have different degrees of hearing loss), often one of the ears with a hearing aid, without binaural fitting, may be the reason for the price, may be psychological Feeling uncomfortable and other reasons, when you see the importance of binaural fitting, you should pay more attention to the recovery of hearing, the health of your ears.

Jinghao medical hearing aid reminder: hearing aids need to be professionally “fitted”, it is very important to choose a professional hearing aid fitting center and hearing aid fittings! All patients and friends have any hearing problems can call the Jinghao medical consultation, or personally Come to the fitting center experience. Hearing aid free consultation phone: +86-752-2299187

You can also email us: Jinghao14@jinghao.cc for more information you want to know.

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