Effect of noise on Human ear
Effect of noise on Human ear: The sound pressure waves enter the auditory canal and cause the Eardrum (Tympanic Membrane) to move in sympathy with the pressure fluctuations. Three minute bones called the Hammer, Anvil arid the Stirrup (the Ossicles) transmit the Vibrations via the Oval window to the’ fluid in the miner ear and hence to the minute hairs in the Cochlea, These hairs are connected to ‘the nerve cells which respond to give the ‘sensation of hearing. Damage to, or deterioration of these hairs, whether to the exposure to high noise level, explosion or ageing will result in loss of hearing.
Noise induce hearing loss (occupational hearing loss) is caused by over stimulus of the receptor cells in the Cochlea resulting in auditory fatigue. In its early stage it is often shown as an increase in the threshold of hearing temporary threshold shift. It may be accompanied by a ringing in the ears (tinnitus).
Which is indicative of temporary hearing damage? If exposure to high level noise is continued, the result would be a “permanent threshold shift” or noise induced deafness. The effects of noise induced deafness are affection of speech frequencies in which the sufferer losses to hear the consonants and speech sounds like a series of vowels strung together.
The performance of the ear evaluated by taking an audio gram. Audio grams normally performed in an Audiology Room which has Avery low internal noise level and vibration isolated. The audio gram obtained by detecting the levels of which specific tones can heard and ceased to heard by the person tested.
Effect of noise on Human ear
Auditory effects of noise
Short Exposure to High Intensity Noise:
Ruptures of the ear-drums have observed to occur under these conditions.
The victim may completely unaware of the early stages of impairment and may only detected on medically examination. Clarity of-heard speech affected first. Ringing in ears happen to most and as the loss increases the Victim hears his own voice leas clearly and often speaks loud.
Temporary Threshold Shift:
This sometimes known as auditory fatigue arid refers to any loss from which the ear recovers however long may the time taken. Majority of TID occurs during the first hour of exposure.
Effect of noise on Human ear, Permanent Hearing Loss:
Hearing loss occurs first in the 3-6 K2 band and progressively increases with time if the working environment continues to be same.
Everyone does not develop the same hearing loss when exposed to same noise. Some are more susceptible than the others and undergo impairment quickly.
Noise reduces output and efficiency and affects morale. Annoyance increases with sudden fluctuations of sound of employees
Exposed to such environment:
Fatigue often caused by high pitched continuous sound.
In certain circumstances noise may cause
- Decreased electrical resistance in the skin.
- Reduce gastric activity
- Increase muscle tension
- Occasional dizziness
- Rise in breathing, heart rate and blood pressure.