Method of converting recording environment for recording speech

A method of converting recording environment for recording speech mainly uses a filter to convert a piece of digital speech recorded from certain recording environment such as microphone recording environment) into a piece of speech seemingly recorded from another recording environment (such as analog telephone or mobile phone recording environment). This method allows a speech recognition system in a training stage to provide sufficient speech material which is similar to the recording environment, even when there is no enough training speech available in the applied recording environment, for performing speech recognition model training and thus can be used as a processing method for eliminating speech channel effect in the speech recognition stage.