In this paper, we reported the result of a questionnaire survey with the Deaf or Hard of Hearing people (hereafter: DHH) employees working for Company Z, which has been actively employing DHH since the 1980s and provided advanced support, like hiring sign language translators. For better support for DHH employees in the future, we asked them 1) what kind of means they use for communication and what kind of relationships they have with their hearing supervisors, hearing colleagues, and DHH colleagues. 2) How their human relationship correlates with their job satisfaction. In company Z, a very few DHH employee was working with another DHH employee. In such a particular situation, the result showed that the relationship with supervisors was more correlated with job satisfaction than the relationship with DHH colleagues, and the relationship with hearing colleagues was more correlated with job satisfaction than the relationship with supervisors. However, only about 30% of respondents said they could use their preferred means of communication with their supervisors and hearing colleagues. Fewer than 20% of respondents strongly felt that they could chat with their supervisors and hearing colleagues and that their supervisors and hearing colleagues contributed to their job development. The result suggests that in company Z, close relationships with hearing co-workers and supervisors are essential to creating a rewarding work environment for DHH employees.