Literature on speech skimming reports on techniques for playing speech backwards in a way that is still intelligible to the user. However, so far there is no empirical evidence for reasonable parameter settings of the respective algorithms and few examinations have been conducted to verify the usefulness of this feature for actual tasks. We present a user study testing different ways of backward skimming in relation to topic classification. Our evaluation shows a high classification performance and suggests implications for the design of the user interface.