# Effects of Auditory Pre-Stimulation on Cognitive Task Performance in a Noisy Environment
## 1 Introduction
In Korea, the average noise exposure level at 16,359 workplaces in 2015 was 83.6 dB (A), and more than half of the noise measurements exceeded the exposure limits in 13.7% of the workplaces tested [35]. In light of the fact that noise is prevalent in most industrial sites, as mentioned above, it is important to devise measures to mitigate the adverse noise effects on cognitive task performance in order to prevent human errors and better ensure industrial safety. Working memory (henceforth referred to as WM) is the basis of fundamental cognitive functions, such as rehearsal, reasoning, decision making, action planning, problem solving, situation awareness, and perceptual processing (bottom-up/top-down processing) [36; 37; 38]. In addition, WM has been found to be associated with the occurrence of various types of human errors [4; 38; 39]. According to [PERSON]'s model [40], the WM system consists of three subcomponents, that is, the visuospatial sketchpad, the phonological loop, and the central executive. The visuospatial sketchpad and the phonological loop are short-term memory (henceforth referred to as STM) components of WM, as they are intended to temporarily hold/process visuospatial and auditory-verbal information, respectively, and the central executive provides executive control of WM by monitoring and manipulating the STM components. Note that a fourth component to the revised model [41], the episodic buffer which provides a temporary interface between the slave system (the phonological loop and the visuospatial sketchpad) and long-term memory, was not considered in this study since it is assumed to be controlled by the central executive [41]. As noted earlier, it is known that cognitive task performance can be reduced in a noisy environment [22; 23; 24; 25; 26; 27]. However, to the best of the authors' knowledge, less attention has been paid to how a noisy environment affects the performance of basic STM/WM tasks related to different functions of WM. This lack of research and knowledge hampers the ergonomic designs of work tasks and environments to minimize the adverse effects of noise at noisy industrial sites, which can eventually result in a decrease in cognitive task performance and thereby an increase in the rate of human errors/accidents. In an effort to fill the above-mentioned research gap, this paper seeks to address the following unexplored research question:  
_Research Question 1_. How will a noisy environment affect the performance of basic STM/WM tasks related to different functions of WM? In recent years, numerous scholars have demonstrated the effectiveness of auditory pre-stimulation as one way to improve workers' cognitive task performance. Several studies revealed that listening to classical music prior to a variety of cognitive tasks significantly increased the cognitive task performance by improving the levels of arousal or positive affect in the listeners [42; 43; 44; 45]. [PERSON] et al. [46] also demonstrated that listening to white noise in advance of a task helped to improve the work efficiency of workers by making them feel emotionally stable and improving their concentration. [PERSON] and [PERSON] [47] demonstrated positive effects of listening to meditation music programs before a class on attention and learning attitudes among college students. [PERSON] and [PERSON] [48] investigated the effects of different musical genres on mental focusing; their study showed that a group that listened to binaural beats prior to an attention test showed higher mental focusing than those who listened to classical or popular music. Judging from the results of these studies, it appears that providing workers with appropriate auditory pre-stimulation can contribute to improving their cognitive task performance, thereby preventing human errors. Despite earlier work, however, our understanding of the effects of auditory pre-stimulation on cognitive task performance in noisy environments is very limited due to insufficient relevant research.