Abstract
Most of the approaches to increase the robustness of a speech recognition system in bad acoustic conditions can be classified in two categories. The methods of the first class are based on an extraction of acoustic features that should be independent of the acoustic condition. Alternatively, the parameters of the HMMs can be adapted to the acoustic condition.Both principal approaches will be presented in the talk as well as some exemplary realizations. The advantages and disadvantages will be shown. An approach will be shown in more detail to adapt the HMM parameters to the condition of a hands-free speech input in a reverberant environment. Some demonstrations will be included to enlighten the applied methods.