Writing is an important activity in open-plan study environments in higher education. Writing is also a task during which students have indicated to be very disturbed by background speech. The aim of this study was to analyze the influence of realistic sound scenarios in an open-plan study environment on the performance and disturbance of participants working on a writing task, taking into account noise sensitivity as a personal factor. In an experimental setting, participants had to perform a writing task while being exposed to different simulated sound scenarios. These sound scenarios were composed of background speech produced by three or fourteen talkers in a very absorbing (0.6 s) or very reverberant (2.4 s) open-plan study environment. A quiet sound scenario was added as a reference. Results show that the writing performance of participants decreased significantly in the absorbing environment with only three talkers. Although the quiet reference environment was rated as the least disturbing, the performance in the quiet reference condition was not significantly better compared to the other acoustic conditions.