Why does hearing loss always start at high frequencies?
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Why does hearing loss always start at high frequencies?
Normal There is more decline from high frequencies, because the outermost part of the human cochlea is the base of the cochlea. The base of the cochlea plays a role in analyzing high frequencies, while the top of the cochlea is located inside the cochlea and generally suffers less damage. Therefore, hearing loss is generally caused by hearing loss. It starts from high frequency, of course, it also starts from low frequency and decreases, it depends on the person.
Generally speaking, the frequency range that human ears can hear is between 20Hz and 20,000Hz. Frequencies above 4,000Hz are called high frequencies. Normal communication between people only requires the normal hearing function of the cochlea at frequencies of 500Hz to 3000Hz. Therefore, when high-frequency hearing is damaged, people are often completely unconscious. The frequency of hearing loss caused by high-pitched headphones is precisely at high frequencies. Once high-frequency hearing loss decreases, it will slowly expand to low frequencies. If high-frequency horizontal hearing loss does not attract people's attention and noise pollution still exists, horizontal hearing loss in other frequency bands will also have problems, which will slowly affect people's normal functioning. Language Exchange.
The higher the frequency, the more susceptible areas are to damage, which is determined by many objective factors. It is mainly related to the natural resonance effect of the external auditory canal, the anatomical structure of the cochlea and the distribution of the auditory nerve. The outer layer of the auditory nerve is composed of nerves from the base of the cochlea, which transmits high-frequency sounds; the central part is composed of nerves from the top of the cochlea, which transmits low-frequency sounds. Changes in the physical and chemical environment such as trauma, ischemia, and hypoxia will first affect the outer nerves from high frequencies.
Since birth, the range of sounds that most people can hear gradually shrinks as they grow older. The process of gradually shrinking from the initial 16-20000Hz is actually the process of hearing loss. This is a natural aging process. Therefore, senile hearing loss mostly starts at high frequencies.
In addition, from a physiological structure point of view, high-frequency perception is mainly performed by the outer hair cells of the cochlea. These hair cells are most susceptible to the effects of drugs or noise, and are also in the most vulnerable position to damage. Therefore, most hearing loss starts from high frequencies.