Non-auditory effects of noise.
Noise simply refers to the undesirable exposure to uncoordinated, unrefined sound of frequency higher than what the human ear is capable of adapting, to make out sensible interpretation through relay to the brain through the auditory pathway. The effects of noise can be described as chronic or acute. The chronic effects develop over time on continual exposure to noise. This is sometimes noticed in people living close to airports. Their auditory system gradually becomes insensitive and they have a hard time discerning subtle differences between sound levels. In terms of debilitating effects, noise can be biologically classified into auditory and non-auditory noise. The effects of noise have been categorised into the auditory effects and the non-auditory effects. The auditory effects are traditionally seen as the effects of exposure to loud noise. Over the years however, researchers have pointed to other effects that exposure to loud noise might result into, they constitute the non-auditory effects of noise.
Q.1. what is the distinction between auditory and non-auditory effects of noise? (15% of marks)
Auditory effects of noise include all pathologies that directly arise as a result of acute or chronic exposure to high levels of noise i.e. a high pitch of sound that is haphazard. These pathologies involve the auditory system or the pathway along which the sound waves pass from the ear to the brain. It basically involves hearing loss or abnormal ear response to low or high pitch of regular sound of normal intensity.
Non-auditory effects of noise, on the other hand, involve all other pathologies or morbidities that arise as a result of exposure to a high level of noise with no connection with the anatomical arrangement of the neither auditory systems nor pathway. Such thus has noticeable or significant effects in the other part of the body. They include cardiovascular effects, psychosis e.t.c.
Q.2. Briefly, describe six non-auditory effects of noise. (30% of marks)
Cardiovascular effects: This is an important non-auditory effect of noise that leads to reduced adaptation of the ear to increasing sound levels. Reports have shown that high blood pressure results from progressive increase from early childhood to adulthood on constant exposure to noise. Headache is another resultant sign from vasodilatations of the intracranial vessels. The intracranial vessels dilate because of the increase in the level of blood Adrenalin, released by the adrenal medulla. Adrenalin is an endogenous substance released as part of the ‘fight or flight’ mechanism of an individual. Anxiety can also precipitate the release of these.
hormones. They are part of The Sympathetic division of the Autonomic Nervous System.
Also, in patients with cardiovascular diseases, heart attacks could arise from hearing a loud noise. This could lead to an urgent medical condition in which a defibrillator has to be used to resuscitate the individual.
Annoyance: Emotional discomfort results from noise exposure. A patient from a quieter environment has an unusual attitude to sudden or bizarre environment where noise persists. The annoyance is significant because of its graduation to depression or anxiety as the strangeness persists. Sleep disorder (insomnia) is also a complication of annoyance. This can significantly reduce the productivity of an employee in his place of work.
Psychical Irritations: in the school of medicine, one of the noticeable effects of non-auditory noise pollution is meningeal irritation. Meningeal irritation could arise from the dilation of the intracranial arterioles. This dilation arises from the release of endogenous substances like Adrenalin. Adrenalin is released as a response to stressful situations.
Physical harm can arise from hearing a sudden loud noise especially when the environment has been quiet for a long time.
Behavioural disorders: Non-Specific syndrome effects of noise pollution from the immediate surroundings are evident in the patients’ reaction in social group or peer groups. This could come in form of intolerance to personalities. Intolerance can lead to a significant decrease in the productivity of employees that did not have inadequate sleep during the night. These workers get to their place of work and because of the stress they have gone through during the night; they are not able to perform to their optimal level. This could lead to loss in manpower hours which cause a significant loss in income.
Memory dysfunction: A reader in a noisy environment most time experience an initial phase of assimilation reduction within a marked range of time relative to previous experience. This effect is more pronounced in children. Children are more prone to memory dysfunctions on chronic or acute exposure to loud noise. It has been found out that Attention Deficient hyper active Disorder can be aggravated by chronic exposure high levels of noise.
Learned helplessness has been reported in children. Learned helplessness means that the individual learns that the outcomes of his/her behaviour are independent of the actions of the individual. The individual is less motivated to perform actions that are usually rewarded. This is a major disorder noticed in children and it significantly reduces their ability to learn new tasks and chores. The reward system is a major avenue of impacting knowledge in youngsters.
Q.3. what non-auditory effects are considered to have the firmest evidence for their existence? Give one example of evidence for each of the effects. (15% of mark)
Emotional/ Motivational Effects- exposure to a high level of noise can induce learned helplessness in adults. Repeated exposure of residents to noise can be associated with feelings of helplessness among adults living near noisy areas especially if there is nothing they can do to reduce the noise levels, this behavior is seen most in people living near airports. Also, it was found out that in children, the reward system is not very effective in impacting knowledge into those children suffering from exposure to high noise levels. Motivation was noticed to be lacking in them.
Cardiovascular Effects: The cardiovascular effects, among other things cause heinous medical complications that may lead to medical emergencies in people exposed to high levels of noise. This effect is pronounced in individuals with weight problems (obese individuals), most especially the middle-aged American populace. In a critical review of literature regarding the non-auditory effects of noise, Evans, G affirmed that ‘Residing or attending school near a major noise source is associated with elevated blood pressure.’ This effect was noticed in school children.
Cognitive Effects: researchers have done a great deal of work in the effects that high noise levels in people. A strong link has been established between reading and high levels of nose. Most people generally have problems concentrating on reading in noisy environment. Loud noise affects the level at which a material is assimilated. This effect is has a great implication in students especially when trying to understand new materials. Concentrating in a quieter environment usually works a great deal in familiarising with new materials.
q.4. Give 3 examples where further research on non-auditory effects is needed indicating the kind of research that is needed in each case? (15% of mark)
Firstly, more specific findings are still needed to give scientific details on psychic irritation. To scientifically approve and graduate thesis into laws, the reason why some traits of individuals vomit on hearing strange noise. The relationship of the trio pathway: non-auditory-brain irritation centre-gastrointestinal tract irritation.
In addition, the controversial thesis that some children within noisy environment retain the essential “information in tuning out distracting auditory stimuli among” discriminating noise is deficient in further expository research. Brain cells are some how impaired when performing multipurpose tasks because they require various neuronal interconnections of the cells for processing (Dr. Lorraine E. Maxwell & Dr. Gary W. Evans, n.d.)
Moreover, I suggest that further researches should be carried out to figure out if at all there is interplay between the different non-auditory effects of noise and if at all there is any. There might be some masking effect that one non-auditory effect has on the other effect. Further researches would figure this out and give more valid reasons why these effects come by.
To all these researches, prospective, longitudinal studies are suggested as a way of carrying out these researches. They are the strong experimental designs that can be applied in field studies. They minimise errors due to confounders and they tend to eliminate bias arising from self-selection.
q.5. explain the importance of control groups in epidemiological studies. (10% of mark).
Control group is a separate category among various groups involved in experimental case study. It is expected to serve as a comparative standard reflects any short fall in the series of mapped out groups earmarked for study. Control groups constantly remind researcher of the normal as compared to abnormal. In addition, it authenticates the outcome of the report. This goes a along way in instilling confidence in the thesis or principles emanating from the report. The control groups earmarked in an epidemiological study buttress the sustenance of the test of time.
Control groups significantly reduce the effect of confounders in researches. Biases may also arise if a research is carried out without the use of control groups.
A research design is basically incomplete until control groups are included. Control groups give a basis for comparison with the effect of the variables being tested for.
In clinical and pharmacological researches, especially in drug trials, control groups are regarded as placebos. Placebos are used to test whether the effect of the drug that is noticed during the trial is a true reflection of the real effect of the drugs.
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2. Peterson and co-workers (Peterson et al., 1981) of the Department of Otolaryngology, University of Miami School of Medicine.
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