Hearing impaired patients need to undergo hearing tests before choosing hearing aids. There are generally some professional terms in the test process and test reports. In order to let users better understand their hearing conditions, it is necessary for users to understand some difficult test terms. .NextHearing Aids Made in ChinaA brief introduction for everyone:
First: the shadow curve.In view of the fact that the binaural hearing loss is greater than or equal to 40db, the good ears will replace the bad ears to respond, so that the response curve of the bad ears is consistent with the curve of the good ears, but the degree is different by 40db.
Second: effective masking.The purpose of deciding to prevent the noise intensity generated by cross hearing is to eliminate the effect of cross hearing. It is necessary to select an appropriate noise level to prevent non-test ears from participating in the test.
Third: Mask up.The upward propagation of masking means that low-frequency sound masks high-frequency sound.The main frequency of the environmental sound is lower than the main frequency of the speech sound, so it often interferes with us hearing the speech sound. The upward masking can occur at any time. The high-frequency components in the speech play an important role in clarity. If a low-frequency phoneme is not achieved Proportionally louder than a high-frequency phoneme, the weaker high-frequency sound will be masked, resulting in the same result as high-frequency hearing loss. This may be related to the physical characteristics of the basement membrane’s low-frequency influence area than the high frequency. Another explanation is When the low frequency reaches the parietal circle of the cochlea, it always passes through the high frequency area first.
Fourth: cover backwards.When a loud voice followed by a small voice, only the loud voice was heard, and the small voice that appeared first was not heard.
Fifth: Forward masking.When one sound appears immediately after another, the hair cells will be less sensitive due to the stimulation of the first sound, which makes the subsequent sounds sound lighter.
Sixth: Central cover.When masking noise is introduced into the non-test ear, even if the intensity of the noise is not enough to cause over-masking, it will still cause the phenomenon that the threshold of the test ear rises.Approximately 5 decibels.
Seventh: Insufficient masking.When the masking sound of the non-test ear is not enough to eliminate cross hearing or inter-aural attenuation, the subject can hear the noise and signal sound at the same time in the non-test ear.The minimum sound obtained is lower than the true threshold of the test ear
Eighth: Over-masking.When the masking sound is too large to be heard by the test ear through the bone conduction reaction, its threshold value rises, which is actually equivalent to ipsilateral masking.
Chinese hearing aid opticians say that insufficient masking will lower the threshold, while excessive masking will increase the threshold.Ideally, the masking sound we choose is the best that can effectively complete the entire test process.