【Basic Knowledge of Occupational Health】 – Hearing Threshold

“The term “threshold” is pronounced as yù; it refers to a boundary or range. Hearing threshold: Generally, the vibration frequencies that human ears can detect lie between 16 and 20,000 Hz. For each of these frequencies, there is a minimum intensity of vibration required to trigger hearing, and this minimum intensity is known as the hearing threshold. The hearing threshold varies for sound waves of different frequencies. The human ear is most sensitive to sounds at 1000 Hz, with a hearing threshold sound pressure of P0=2*10-5 Pa (referred to as the reference sound pressure).

1. The highest and lowest intensity of stimuli that can produce hearing. The appropriate stimulus for the ear is compressional and rarefactive waves of air vibration; however, the frequency of these vibrations must be within a certain range and reach a certain intensity in order to be detected by the cochlea and to trigger hearing. Typically, the vibration frequencies that can be detected by the human ear range from 16 to 20,000 Hz, and for each of these frequencies, there is a minimum vibration intensity required to trigger hearing, known as the hearing threshold. The auditory threshold of the human ear varies for different frequencies; for example, the auditory threshold for a 1KHz pure tone is approximately 2*10^(-5)Pa. As the vibration intensity continues to increase above the threshold of perception, the auditory sensation also increases accordingly. However, when the vibration intensity reaches a certain limit, it causes not only auditory sensations but also pain in the eardrum; this limit is known as the maximum audible threshold. Since there is a hearing threshold and a maximum or threshold value for each vibration frequency, it is possible to create a coordinate graph showing the range of sensitivity of the human ear to vibration frequencies and intensities, as shown in the figure on the right. The curve below represents the hearing threshold for vibrations at different frequencies, while the curve above shows their maximum hearing threshold; the area enclosed by both curves is referred to as the hearing range. For any sound that can be perceived by humans, its frequency and intensity values must lie within the range of the audible spectrum. As can be seen from the audiogram, the frequency range to which the human ear is most sensitive is between 1000–3000 Hz ； The frequency in everyday language is slightly lower than this, while the intensity of the sound is at a moderate level, between the hearing threshold and the maximum audible threshold.

The range of sound frequencies and intensities that the human ear can detect

I’ve learned it.* I can’t read some of the characters related to the threshold term, so I read them with the YU sound, following the method used by scholars in Shandong. ;P

Typically, the vibration frequencies that can be detected by the human ear range from 16 to 20,000 Hz, and for each of these frequencies, there is a minimum vibration intensity required to trigger hearing, known as the hearing threshold. Why am I keep practicing the valve:L

“Why do I keep practicing the valve?” What does that mean?