## 1 Introduction  
Occupational noise-exposure is a known risk factor contributing to the growing prevalence of hearing loss worldwide [1]. Unfortunately, more and more workers are exposed to hazardous levels of noise in the workplace due to the expansion of industrialisation, especially in developing countries [2, 3]. In Malaysia, occupational noise-related hearing loss has consistently been the most prevalent occupational disease over the past several years [4]. Employers are required by law to protect workers from excessive noise exposure by implementing a hearing-conservation programme at the workplace. Although engineering and administrative controls are the preferred methods used to control noise hazards, they are not always practicable or adequate to eliminate all harmful noise. In such cases, personal hearing-protection devices (HPD) are still necessary to protect workers. Previous studies among Malaysian workers have generally shown poor compliance with HPD usage [5, 6, 7, 8]. [PERSON] et al. (2016) reported that manufacturing workers use HPD 39% of the time when exposed to high levels of noise at work [5]. A study among quarry workers showed that only 14% of them claimed to have used earplugs at the workplace, while another study in sawmills reported that only 9.6% of workers had always used earplugs while working [6, 9].  
Numerous interventional studies on the use of HPD among noise-exposed workers have taken a targeted or tailored approach to constructing a form of intervention [10]. A targeted intervention is an intervention developed based on the shared characteristics of members of a group [11]. In contrast, a tailored approach considers the characteristics of an individual rather than a group to devise an intervention [11]. A systematic review of these interventions has shown that tailored interventions are more effective than targeted interventions at improving the use of HPD [10]. However, a targeted intervention can also produce desirable results while providing better value due to its cost-effectiveness compared to a tailored intervention [12]. The issue of cost and complexity in implementing an intervention is particularly relevant for industries in developing countries, more specifically for small and medium enterprises.  
In a study involving factory workers, comparisons were made between three intervention groups--tailored, non-tailored, and control. It was shown that the tailored intervention contributed to a slight improvement in HPD use among the participants. As for those in the non-tailored and control group, no significant changes were detected [13]. Another study compared a computer-based tailored intervention with a control intervention. The participants' intention to use HPD in the future was assessed immediately following the intervention. The tailored group reported a greater increase in the intention to use HPD than the control group. However, at twelve months post-intervention, self-reported HPD use did not significantly differ between the groups [14]. [PERSON] et al. (2007) assigned construction workers to tailored and targeted intervention groups, with both groups receiving their respective interventions via interactive computer-based educational sessions. In addition to the single-session intervention, the trial included the usage of boosters. In terms of improving HPD usage among participants, the targeted method was demonstrated to be just as successful as the tailored approach. The effect of boosters on HPD usage was found to be non-statistically significant [12].  
Considering the trend of industrialisation in Malaysia, there is a need for a hearing-protection training module that could boost compliance with HPD usage among agro-industrial and manufacturing workers. This study aimed to develop and determine the efficacy of a hearing-protection training module that could improve the use of HPD among these workers.