Design of Safety Drive Training System for Hearing-Impaired People

Individuals with hearing impairments in Indonesia face significant driving limitations that hinder their daily mobility. According to 2022 data from the Central Bureau of Statistics (BPS), 1,876,462 individuals of productive age experience hearing difficulties, which can disrupt communication and interaction, as well as obtaining official driving permits. To address this issue, a study is proposed to design an assistive module that converts horn sounds into vibration indicators on the steering wheel. These indicators have three urgency levels (Extremely Urgent, Urgent, and Low Urgent) based on the Sound Pressure Level (SPL) and distance of the horn sound. Testing was conducted at distances of 1 meter,3 meters, and 5 meters, with threshold values determined based on SPL readings inside the vehicle, which showed attenuation of 20–30 dB compared to outside the vehicle. The thresholds for each level are: Extremely Urgent at 83 dB (100% vibration), Urgent at 65 dB (75% vibration), and Low Urgent at 50 dB (50% vibration). Trials with 5 normal subjects demonstrated that the accuracy of receiving horn signal messages increased from 69.67% without the module to 100% with the safety drive training system module. To minimize errors in SPL readings and enhance the module's capability to be used in various weather conditions, it is recommended to use appropriate sensor selection and an additional ADC module for more precise SPL readings. Moreover, the involvement of hearing-impaired subjects is also crucial to directly observe their responses for further research development.