This thesis identifies a relatively new phenomenon in AVT called simultaneous subtitling and dubbing. This occurs when viewers receive two different translational modalities at the same time, where the two translations frequently differ. Current academic and professional standards for the creation of both subtitles and dubbed audio are compared and applied to a case study of the television series Glacé. The case study was evaluated using an error-and-verbatim subtitle analysis equation called the NEF model, that accounts for minor, major, and critical errors found in comparing the interlingual subtitles to the interlingual dubbed audio. The NEF model provided both percentage and a point scores which showed that, while there was a high level of adhesion to professional standards, the majority of the examples failed to meet the minimum 96.4% score. Based on these findings, I propose eight new standards to be considered during the creation of simultaneous subtitling and dubbing.