Technology advancement has brought faster development for modern industry. They have installed many 24-hour telephone customer services domestically and internationally to provide timely assistance to their customers in order to increase their satisfaction and promote the image of business. However, the increasing workforce of telephone customer service needs to face the musculoskeletal injuries common to office workers as well as the problem of hearing loss resulting from receiving phone calls over an extended period of time. This study aims to investigate, from the perspectives of ergonomics, the condition of hearing loss among the telephone customer service workers and the associated risk factors, in order to provide useful information to relevant government and authorities for questionnaire with personal basis variables, work related variables, personal habit variables and non-work related variables according to the characteristics of telephone customer service workers. In this study, 286 questionnaires were distributed and 282 returned, with 280 rendered valid. The results show that 61.8% of telephone customer service workers sustained head and ear discomfort in association with jobs, among which for 58.9% the discomfort was with ear discomfort. The major risk factors with the telephone customer service workers include: the type of headphone, sound volume applied, and background noise in the office. The researcher believes the founding in this thesis will not only mitigate the injuries mentioned previously but also provide references for telephone customer service workers for the institutions concerned, which will substantially contribute to the alleviation of such injuries.