One of the benefits of wearing a hearing aid in both ears is called “eliminating the cephalometric effect,” so what is called elimination?Head shadow effectHowever, 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 toward the sound source. This is the head shadow effect.
In terms of acoustic angle, the cephalometric effect is that 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 cephalometric effect, which is caused by the barrier function of the head. 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 skull plays a role in hindering and attenuating the transmission of sound waves, especially above2000HzHigh frequency sound, its attenuation can be reached10~17dB. Therefore, the clarity of the hearing aid is greatly reduced. A patient with a large number of single-sided options can be very difficult to hear when listening to the sound from the contralateral ear, often with the hearing aid’s wearing 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 ear, and it is easy to listen to the sound from multiple directions.