This study investigates using the concept of norms whether English-Thai interpreters regard direct speech as an appropriate interpreting style in simultaneous interpreting. It also explores whether gender-specific linguistic terms in Thai, which consist of first-person pronouns and formality-marking particles (FMPs), affect the interpreter to deviate from direct speech. Questionnaires and interviews were used to collect data. As a result, 12 interpreters answered the questionnaires, and four interpreters participated in the interviews. The results show that direct speech is the norm among the interpreters in this data set: 90.9% of respondents believed that English-Thai simultaneous interpreting should be done in the direct style, and 58.3% regularly used first-person pronouns and FMPs based on the speaker's gender. However, some respondents did not use first-person pronouns or FMPs along these lines. Some of their reason might be to avoid gender-specific terms. The interviews' results also showed that although the negative feelings toward using different-gender first-person pronouns and FMPs were different among individuals, all four interview participants admitted that they had misused FMPs when interpreting for the different-gender speakers. The results, therefore, suggest that gender-specific terms induce the interpreters to shift from direct to indirect speech.