Ghasemi-2023-White Noise And Its Potential App Part 3

According to Table 2, for more than three decades, the effects of WN on cognitive functions such as working memory, long-term and short-term memory, implicit memory bias, recall, learning, attention and selective attention, cognitive and perceptual tasks, semantic priming, and visual working memory have been studied. 

As the climate changes, our environment is also constantly changing. Increases or decreases in temperature, changes in air humidity, etc. will affect the normal functions of our bodies and have an impact on our brain function. These effects will inevitably have a certain impact on our memory, but they are not negative. Some experiments have shown that moderate climate change can improve our memory.

Experiments show that appropriate temperature and humidity can enhance our memory. If the environment is too hot or too dry, it will cause us to feel tired and uncomfortable, affecting the normal working of our brains. Moderate temperatures and humidity can keep our bodies comfortable and help us focus and concentrate better. These factors all help strengthen long-term and short-term memory, making it easier for us to remember and learn new information.

In addition, climate change also affects our daily lives, stimulates our concern for the ecological environment, and enhances our sense of social responsibility. Initiatives such as protecting the environment, reducing waste, and conserving energy not only help curb the effects of climate change but also have a positive impact on our brains. The implementation of these measures requires our action and creativity, which will help us exercise our brains and enhance our self-confidence and psychological quality.

In short, appropriate climate change can improve our physical condition and brain function, helping us learn and remember better. Of course, any change will have some impact on us, but we just need to actively face and deal with these impacts to maintain a healthy body and a positive mentality. It can be seen that we need to improve memory, and Cistanche deserticola can significantly improve memory, because Cistanche deserticola can also regulate the balance of neurotransmitters, such as increasing the levels of acetylcholine and growth factors. These substances are very important for memory and learning. In addition, Meat can also improve blood flow and promote oxygen delivery, which can ensure that the brain receives sufficient nutrients and energy, thereby improving brain vitality and endurance.

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According to the findings of these studies, which investigated WN at intensities of 60 to 86 dB, WN may be able to reduce distracting factors from the environment, improve attention and concentration, improve learning and memory, and enhance performance in tasks involving sequential short-term memory (25-29). 

Taking a broad view, one can say that by adding an optimal level of WN in certain situations as an intervention, one can expect to improve cognitive functions and facilitate information processing in the nervous system.

In these experimental-interventional studies, however, the subjects were primarily students, older people, and patients, with one study involving animals. Consequently, the impact of such interventions on the cognitive functions of industrial workers has not yet been studied, so further research is required.

On the other hand, WN can effectively treat some symptoms of ADHD, one of the most common neurodevelopmental disorders in childhood and adulthood (Table 3). Several items such as improving reading and writing speed, speech recognition, controlling off-the-job behaviors, raising awareness and assisting working memory tasks, and rarely improving the accuracy of tasks have been proven effective in studies. 

Nonetheless, it has yet to be established whether WN affects the speed of reaction and response to stimuli (30-33). 

To the same extent as what has been said about cognitive functions, studies have predominantly investigated the effect of WN on ADHD in school-age children and students, so finding its role in adults and employees requires further investigation.

White noise therapy
Besides what has already been discussed above - treatment of ADHD symptoms, the literature review suggests that WN has also proven helpful in treating depression, anxiety, stress, schizophrenia, dementia, relieving pain, improving vital signs, and sucking success in newborns (Table 4).

Accordingly, WN reduced verbal agitation in patients in nursing homes with dementia, decreased behavioral and psychological symptoms in patients with schizophrenia with dementia, improved depression and anxiety symptoms, decreased heart rate in elderly patients admitted to the CCU, reduced pain during vaccination, and helped develop sucking behaviors in newborns (14, 43-45).

Discussion

WN is being used in various fields that may hold promise for its application in occupational health sciences and maintaining the well-being of workplace workers. By involving long-term memory structures, such as the hippocampus, and by enhancing learning capacity, WN simplifies and improves the learning process for new vocabulary (25, 26).

According to polysomnographic studies, adding mixed-frequency WN to the ambient noise led to a significant reduction in sleep-induced arousal and sleep disturbance since the difference between background and peak sounds was significantly reduced. Thus, WN promotes more profound and more restful sleep (18-21).

Additionally, it can improve sleep-wake cycles and reduce the delay in falling asleep (17). 

WN can reduce distractions by reducing the number of noise changes in the surroundings and bringing a sense of privacy when working (33).WN facilitates information processing in the nervous system, which can benefit specific (but not all) aspects of cognitive function such as learning, memory, attention, and concentration (26, 31, 41).

However, WN can have different effects on people with different attention levels. 

WN can lead to better cognitive tasks for certain people, such as those with ADHD (30). In this way, WN helps people with such disorders compensate for low basal dopamine levels, often resulting from dopamine transport disorders. 

However, it has the opposite or no effect on individuals with normal or high levels of attention (37). The differential benefits of WN in people with ADHD have yet to be fully understood. However, the Moderate Brain Arousal (MBA) model has been proposed, which might provide some explanation for this (33). 

The MBA model of dopamine states that people with ADHD have lower tonic levels of dopamine, which makes their phasic release more prone to hyperactivation via environmental stimuli. 

According to the MBA model, low tonic dopamine levels correlate with low levels of neural activity in people with ADHD, reducing signal-to-noise ratios (SNRs) and performance (33, 41). Thus, the model suggests that the perception of external noise can also influence internal noise in the neural system, so there should be an optimal level for cognitive performance.

Though the exact mechanism of WN's benefits has not been discovered, scientists agree that the sum of WN's positive and healing effects can be attributed to two well-known and possible phenomena: stochastic resonance and noise masking. These two phenomena could explain WN's observed benefits, but there is little data on either, and more studies are needed to draw any significant conclusions.

Stochastic resonance (SR) is a well-documented phenomenon in psychophysics that has been suggested as the mechanism behind the beneficial effects of noise therapy. SR is caused when a signal with too low a power to be detected can be amplified by adding noise. 

Accordingly, random noise enhances neural communication via the phenomenon of SR. SR increases the SNR of transmission, making the signal easier to detect (in this case the detector would be the auditory system) (33, 40, 41). 

In summary, an increase in the level of unpredictable noise, such as WN, results in a higher level of signal transmission or signal detection, or to put it simply, a higher SNR. The SR effect appears to be highly sensitive to both the level of the signal and the amount of noise; this relationship follows an inverted Ucurve function, where performance peaks at moderate noise levels. 

Accordingly, moderate levels of WN are beneficial for performance. In contrast, too little WN does not add the power necessary to bring the signal over the threshold, and too much WN overpowers the signal, deteriorating the ability to pay attention and perform (28, 33).

As part of its task, the central nervous system distinguishes between the signal, the information it carries, and noise (i.e., meaningless neural inputs that interfere with the signal). 

The modulation of neural synchronization enables particular brain regions subserving specific functions to form transient networks that allow perception, cognition, or action to occur (28). As a result, random noise enhances the sense of weak sensory signals and is explained by SR. The concept of SR attempts to explain the paradox that the brain seems to utilize WN to differentiate the signal in the targeted stimuli from non-target noise.

Noise masking occurs when a noise obscures the detection of another sound. WN can be used as a mask to reduce the recognition of other background noises by blocking them. Masking by noise works on the principle that the brain actively processes only recognizable patterns, such as speech, and ignores sounds that are not identifiable as patterns, such as static sounds. 

In essence, noise-masking works by introducing low-level random background noises (usually WN) into the workplace that correlate with human speech frequencies. Meanwhile, controlling the decibel level and frequency of noise added to the environment is crucial. 

Because the noise must be loud enough to interfere with the understanding of conversations at a predetermined distance, the human brain will not be able to ignore the noise if it is too loud, eventually interfering with other processes. The WN can do this well since it can cover speech without distracting or irritating the listener (1, 33).

Nowadays, workplaces often include "open spaces," where many employees work in spaces usually separated by barriers. 

In this work environment, ideas are shared, creativity is fostered, collaboration is emphasized, and productivity at work is increased. Therefore, it is often preferred to have such work environments. 

Nevertheless, everyone cannot work efficiently and effectively in these environments because of noise pollution and the distraction it causes. To maintain the advantages of an "open spaces" layout in the workplace and to maintain employee attention and focus, systems need to mask ambient noise and improve employee concentration. WN-based systems that mask disturbing ambient noise play an essential role in such environments. 

Offices, organizations, institutions, and academic environments, as well as telecommunications, police, and emergency services centers with telephone systems, etc., can benefit from using these systems to improve productivity and comfort. Moreover, it can facilitate speech privacy, allowing employees to be more productive and concentrate. Most jobs in today's society are associated with shift work due to socio-economic conditions and market demands. 

For example, firefighters, manufacturing workers, health care professionals, security guards, and physical security guards work shifts with short rest periods. Sleep delay and difficulty falling asleep are usually the most common problems of shift workers with certain personality traits (50). 

WN devices can prove to be an effective intervention for shift workers suffering from sleep disorders. WN also improves sensory integration and sleep (21). Maintaining focus and attention while working and reducing distractions and reactions to environmental stimuli is essential when performing high-risk jobs or jobs requiring high levels of precision, such as assembly and manufacturing industries. 

WN has been found to affect various aspects of cognitive function (33) empirically. Due to this, the authors of the present study believe that WN is an effective option, especially for those with poor concentration or attention problems in the workplace.

Tinnitus is a well-known disorder in occupations with high noise levels (24). Historically, tinnitus was believed to be only caused by auditory nerve changes and cochlea changes. However, imaging or EEG examinations have shown that central mechanisms and various brain functions may be involved (51). 

In the literature, several treatments have been reported to treat tinnitus, including acupuncture, cranial stimulation, and pharmacotherapy (24). Nevertheless, none of these have reached a consensus and are only helpful in certain circumstances. 

This may be due to the differences between the different types of tinnitus and a lack of standardization (52). On the other hand, WN may prove more beneficial for different types of tinnitus because of its wide band of frequencies and the possibility to mask different sounds with different frequencies. Thus, using a Tinnitus Masker, which continually generates specific sound frequencies, often WN, and which reduces the patient's perception of sounds in the ear, maybe a successful treatment option for many types of tinnitus.

Finally, this study was conducted to address the potential for future research on white noise in occupational health. Nevertheless, the main limitation of this study was the lack or unavailability of results of studies related to occupational health and the improvement of working conditions related to white noise.

Conclusion

Studying WN to determine if it can improve and enhance the occupational health status of workers showed that, despite the viewpoint that noise is destructive and disruptive, WN can be beneficial and even health-enhancing. WN can enhance the work environment and meet occupational safety and health objectives based on the study's results. The results of this study will provide a basis for continuing research into the use of WN in the workplace as an engineering and management control method.

Journalism Ethics considerations

Ethical issues (Including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, redundancy, etc.) have been completely observed by the authors.

Acknowledgments

This study is related to project NO.1399/63717 from the Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran. We also appreciate the "Student Research Committee" and "Research & Technology Chancellor" at Shahid Beheshti University of Medical Sciences for their financial support of this study.

Conflict of interest

The authors declare that there is no conflict of interest.

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