This paper reports on a study of passengers' perception of train interior noise, aiming at determining acoustic thresholds for different passengers' activities. In fact, one of the main advantages of railway transportation is that it allows passengers to engage in a variety of activities during a train journey: reading, working, watching movies, etc. Accordingly, train operators and manufacturers should guarantee that the background noises created by train operation do not prevent passengers to conduct these activities. Therefore, we set out to determine acoustic thresholds by conducting an experiment in which participants were seated in a mock-up of a high-speed train and performed tasks common to first-and second-class passengers (watching a TV series and reading a text). We played back different background noises while they were performing the tasks and they assessed how much the noises had impacted their activities (acceptability ratings). The results showed that, overall, reading a text requires a quieter environment than watching a movie, and quantified the difference. Interestingly, the results also showed that only the loudness of the sounds impacted the participants' judgements when their attention was drawn away from the sounds by the tasks; in contract, our previous work with similar sounds had shown that perception was also impacted by other, different sound characteristics when their attention was focused toward the sounds. Using a more ecological setting such as in this experiment seems therefore more appropriate to determine which aspects of the train noise are important to consider.