Tinnitus is caused by tinnitus causes inner and outer hair cells in the cochlea membrane permeability barrier, or change in hair cell synaptic metabolic disorders, or auditory nerve fibers caused by a short circuit between have 60% of tinnitus sufferers clinicians can find the cause, summarized as the following reasons: 1, ototoxic drugs cause: drug induced tinnitus is divided into two categories, a class of drugs only cause tinnitus without causing hearing loss, because in the Hone Tube analysis these drugs affect the nervous system neurotransmitter associated with biogenic amine metabolism, causing auditory central neurons "convulsions" side effects caused by such as: Some anti-cancer drugs, anti-spasm Jue drugs, antibiotics, macrolide antibiotics, narcotic analgesics, etc. Another drugs both cause tinnitus and hearing loss caused by, or even result in total deafness, tinnitus caused by these drugs are hair cells or auditory neurons damaged the "primary" forms such as: anti-cancer drugs, antibiotics and antiparasitic properties, aminoglycoside antibiotics, etc. 2, the noise reasons: People have such a common experience, if you suddenly heard the sound of firecrackers, there will be a burst ear long reverberations half a day to subside, which is outside noise temporarily damage the human auditory nerve. those long-term work in highly noisy environment, such as tractors and car drivers, traffic police, armed police, military, discos staff, mahjong Entertainer, long meetings, as well as various types of equipment operators, etc., Noise is a victim of long-term noise caused most of the time to stimulate the inner ear nerve damage. noise induced tinnitus mainly for spontaneous activity of the auditory nerve fibers of the disorder. Generally exceed safe noise standards (85-90 dB) intensity noise is may cause tinnitus and deafness, but the noise of the same intensity, there are individual differences in sensitivity, only sensitive to harm or hurt only the extent of the heaviest. 3, the outer ear and middle ear disease causes: the outer ear foreign body (cerumen ) and so reach the eardrum can cause tinnitus; vascular malformations and diseases of the middle ear can also cause tinnitus by clinicians ear examination and treatment, the majority of these tinnitus can be cured. 4, age reasons: people aged over 60 the incidence of tinnitus up to 30%, primarily due to the growth of age, auditory nervous system degeneration due. 5, vascular malformation or rheology reasons: due to such reasons or blood vessels, so that the flow of the brain, the blood supply to the cochlea irregular blood flow, or from the neck, cranial vascular anomalies arising from vascular murmur spread to the ear cause tinnitus. 6, Meniere's disease causes; 7, acoustic neuroma; (mainly by surgery) 8 sclerosis : dense bone lamellar bone labyrinth focal be enriched cells and vascular substitute sponge produced new bone diseases (mainly by surgical treatment) 9, head trauma causes; 10 causes muscle clonus ; 10 a, nervousness reasons; 102, systemic disorders reasons: such as anemia, hypertension, diabetes, hypothyroidism, hypoglycemia, autoimmune diseases, etc. vasospastic disease may be accompanied by tinnitus. 103, while still cause of tinnitus is not clear, accounting for 40% of the number of tinnitus you have not personally seen this, bad judgment, it is recommended that the local hospital, the treatment to see it.
Diodes known crystal diode , referred to as the Hone Tube (diode), In addition, the early vacuum electron tube ; it is a unidirectional conduction current to an electronic device . In a semiconductor PN junction diode has an internal two lead terminals , such an electronic device in accordance with the direction of the applied voltage , with the unidirectional current conductivity. In general, crystal diode is a p-type semiconductor and n-type semiconductor sintered to form a pn junction interface . At the interface of the space charge layer is formed on both sides , constitute a self field . When the applied voltage is equal to zero , due to the pn junction on both sides of the carrier concentration difference due to the diffusion current and the electric field caused by the drift current self equal and in an electrically balanced state, which is the normal characteristics of the diode . Forward voltage is applied when the initial part of the forward characteristic , the forward voltage is very small , the electric field sufficient to overcome the PN junction blocking effect , the forward current is almost zero, which is called a dead zone. This does not make the forward voltage diode voltage called dead zone . When the forward voltage is greater than the voltage after the dead zone , PN junction electric field to be overcome , the diode is forward current versus voltage increases rapidly. In normal use the current range , the diode conduction terminal voltage is almost unchanged , this voltage is called the diode forward voltage. When the forward voltage across the diode exceeds a certain value , the electric field is weakened quickly , the current rapid growth of the diode forward . Is called the threshold voltage or the threshold voltage, the silicon tube of about 0.5V, germanium tube of about 0.1V. Silicon diode 's forward voltage drop of about 0.6 ~ 0.8V, germanium diode 's forward voltage drop of about 0.2 ~ 0.3V.