الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Sound is of great value to living beings for communication. It warns of danger and appropriately arouses and activates us. Sound is a pressure wave traveling in a medium. We normally consider the medium to be air, but sound travels through liquids and solids as well. The audible range is 20-20,000 cycles per second (Hertz).
Sound those are unwanted, unpleasant or harmful become noise. Stress has become an integral part of human life in this modern era. Among the innumerable stressors to which mankind is exposed, noise happens to be a commonly encountered stressor throughout the world.
During daily life, people are exposed to potentially harmful noise levels coming from work environment, urban traffic, and household appliances. Noise exposure is known to affect auditory structures in living organisms. However, it should not be ignored that many of the effects of noise are extra-auditory. The effects of noise vary depending on the characteristics of noise, such as intensity and frequency, exposure time and form, individual age, sex and health condition.
Excessive noise has been linked to a variety of health issues, including:
• Hearing loss.
• Mental illness.
• Sleep disturbance.
• Hypertension.
• Cardiovascular diseases.
• Increased plasma corticosterone levels.
• Elevated levels of cholesterol.
• Reduction in body weight.
• Decrease in gastric secretion.
• Changes in immune response and tumor resistance.
• Decrease in reproductive function.
This work aimed to examine the non-auditory effects on mice resulting from the following different sources of noise:
1- Noise comes from blanking press machine at a factory.
2- Noise comes from different kinds of public transportation at crowded traffic sign.
3- Noise comes from baking furnace machine.
The work studied the effect of these noise sources as a collection (all the frequencies included) from one side and separation the predominant frequency for each noise source and use them as a source of exposure from the other side. The exposure system involved both acute and chronic exposure of mice.
In this work the following materials and methods were used:
• The different sources of noise were recorded using microphone attached to laptop, then saved on mp3 device which then connected to loud speaker. All noise sources intensity was adjusted to be 100 dB at the loud speaker using sound level meter device. Computer software were used to analyze each sound source and separate the predominant frequency for each source then tone generator software was used to generate the predominant frequency tone for each source which adjusted also to be 100 dB.
• Anechoic chamber was designed and performed to insulate the sound. Illumination and ventilation were taken into account upon design. All the exposures were performed inside it.
• The animals used were 130 mice divided to 13 groups classified as the following:
• G0: control exposed (unexposed group).
• GIa: factory acute collection group exposure.
• GIIa: traffic acute collection group exposure
• GIIIa: furnace acute collection group exposure
• GIaf: factory acute predominant frequency group exposure.
• GIIaf: traffic acute predominant frequency group exposure.
• GIIIaf: furnace acute predominant frequency group exposure.
• GIc: factory chronic collection group exposure.
• GIIc: traffic chronic collection group exposure.
• GIIIc: furnace chronic collection group exposure.
• GIcf: factory chronic predominant frequency group exposure.
• GIIcf: traffic chronic predominant frequency group exposure.
• GIIIcf: furnace chronic predominant frequency group exposure.
After the end of the exposure time for all the groups the following parameters were assessed:
• Short memory estimation using recognition index method.
• Blood glucose level.
• Total and differential WBCs count.
• Brain superoxide dismutase activity to indicate the oxidative stress state.
• Brain malondialdhde concentration to assess the lipid peroxidation state in brain cell membrane.
• Brain serotonin concentration to evaluate the neurotransmitter state from brain.
• Histological examination of mice brain and intestine with light microscope at magnification of 40 times for tissue effect study.
The results of the present work are:
1- Very high significant decrease in blood glucose level in all the groups exposed to noise either were acute or chronic compared to control group.
2- Very high significant decrease in total blood WBCs count in all the groups exposed to noise either were acute or chronic compared to control group.
3- Very high significant decrease in brain superoxide dismutase activity in the chronic groups only compared to control group while the changes were non-significant in all the acute groups compared to control group.
4- Very high significant increase in brain malondialdhde concentration in the chronic groups only compared to control group while the changes were non-significant in all the acute groups compared to control group.
5- Non-significant change in brain serotonin concentrations in all the groups exposed to noise either were acute or chronic compared to control group.
6- Very high significant decrease in recognition index in the chronic groups only compared to control group while the changes were non-significant in all the acute groups compared to control group.
7- Very noticeable changes in brain and small intestine histology in all the groups exposed to noise either were acute or chronic compared to control group