What Is the Difference Between Being Hard of Hearing and Deaf?

Noise deaf, disease name. Noise deafness is a chronic process. In addition to subjective feeling of tinnitus in the early stage, patients have no sense of deafness, and conversation and social activities can proceed normally. With the further development of the course of disease (continuing to work in a noisy environment for a long time) when the hearing loss reaches the speech frequency band and reaches a certain level, the patient's subjective perception of language hearing impairment occurs, showing deafness in life conversation, the so-called noise deafness .

Noise deaf

Noise deaf, disease name. Noise deafness is a chronic process. In addition to subjective feeling of tinnitus in the early stage, patients have no sense of deafness, and conversation and social activities can proceed normally. With the further development of the disease course (continuing to work in a noisy environment for a long time), when the hearing loss reaches the speech frequency band and reaches a certain level, the subjective feeling of the patient appears.

Professional

Noise deafness is a kind of occupational ear disease caused by long-term exposure to noise from production machinery, which causes progressive hearing loss and cannot be recovered, so it is also called occupational noise deafness. Occurrence of occupational noise deafness is

In the case of acute acoustic damage caused by gunpowder explosions, rock explosions, production equipment explosions, and firearm launches, the noise intensity often exceeds 140dB, even 170 ~ 180dB. At the moment of an explosion such as artillery or explosives, due to the rapid expansion of high temperature and high pressure gas, the vibration of the gun tube and the fire, the pressure of the surrounding air changes strongly and propagates from the explosion source to the surroundings, resulting in the formation of an explosion pressure wave, of which energy The larger part initially traveled at supersonic speed (1200 ~ 2100m per second). (The violent noise of fireworks and firecrackers produced in violation of safety standards can also reach 120-140dB (A)).

This is commonly referred to as a shock wave; the remaining part is the sound wave (1100 meters per second), which is usually referred to as the strong noise. The energy and speed of the shock wave are gradually consumed and attenuated as the propagation distance increases, so the shock wave travels after a certain distance , Gradually becoming sound

1. The peak value of pressure wave and the duration of overpressure The peak value of pressure wave is the most important parameter in the action of pressure wave injury. Generally, the higher the pressure peak value, the greater the injury effect under the same condition. In addition, when other conditions are similar, the longer the duration of the pressure wave, the greater the injury effect.

2. The characteristics of the pressure wave spectrum are generally such that the energy of the pressure wave is quite concentrated, that is, the energy distribution is a narrow frequency band, and the damage to the listener is more serious than the wide frequency band.

3, the number of exposures under a certain pressure wave conditions, the more the number of exposures,

Noise deaf tympanic congestion or scattered in small bleeding points. Perforation of tympanic membrane, perforation of slack is rare. When the tympanic membrane ruptures, bleeding often occurs. The edges of the perforations are uneven, often triangular, oval, or kidney-shaped. Hearing examination: The degree of hearing loss varies depending on the degree of damage, but the range of hearing loss is mainly in the range of 4000 to 6000 Hz. Cochlear electrogram and auditory brainstem response audiometry can help understand the location of deafness and objectively assess the extent of hearing loss. If necessary for severe blast injuries, high-resolution CT or magnetic resonance imaging may be performed to understand the tympanic cavity, inner ear canal,

Because there is no ideal treatment for cochlear injury, the key is prevention.

Personal protection For those who are engaged in detonation, they should strengthen the education of prevention knowledge so as not to panic in the event of an acute accident; usually wear protective equipment such as earplugs, earmuffs, soundproof caps, etc .; lack of protective materials and foreseeing the imminent explosion The simplest method of protection is to use cotton balls to plug into the ear canal during an earthquake. In an emergency, you can use two small fingers to plug into the external ear canals on both sides, lying down suddenly, facing away from the source of the explosion, using open mouth breathing to reduce the degree of injury. . The sound insulation effect of earplugs can generally reach 20 ~ 35dB. The sound insulation effect of earmuffs is higher than that of earplugs, which can reach 30 ~ 45dB, but it is inconvenient to use. The cotton ball ear can be isolated 10 ~ 15dB.

Chronic sound-damaged deafness. Chronic sound-damaged deafness is a kind of slow-onset sensorineural hearing loss hearing loss caused by long-term exposure to noise stimulation, also known as noise-induced deafness. A type of slow-onset sensorineural hearing loss that occurs due to prolonged production noise stimulation is called occupational noise deafness. Working in a strong noise environment may cause personal injury or death, in addition to interfering with conversations, preventing hearing signals and affecting work efficiency. Noise exists widely in people's work process and environment. Noise deafness is one of the common occupational diseases. It can cause harm to many systems of the human body, such as the nervous, cardiovascular, endocrine, and digestive systems, but the main and specific damage is in the auditory organs.

Health surveillance should conduct employment medical examinations for workers in noisy environments. Hearing records are built into occupational files, and regular medical examinations are conducted in order to find the noise-sensitive and early hearing impaired in time. Then take appropriate measures according to different situations, such as strengthening personal hearing protection measures, symptomatic treatment or tune away from the noise environment. At the same time, the permanent sensorineural hearing loss caused by various causes (pure tone air conduction threshold at any frequency of 500, 1000, and 2000 Hz)> 25dBHL and various diseases that can cause the inner ear auditory nervous system dysfunction are listed For professional taboos.

Personal hearing protection measures Workers operating in a noisy environment must have personal hearing protection as soon as they enter the factory, including wearing earplugs, earmuffs, or hats.