A speech intelligibility enhancing system for enhancing speech, the system comprising: a speech input for receiving speech to be enhanced; an enhanced speech output to output the enhanced speech; and a processor configured to convert speech received from the speech input to enhanced speech to be output by the enhanced speech output, the processor being configured to: i) extract a frame of the speech received from the speech input; ii) calculate a measure of the frame importance; iii) estimate a contribution due to late reverberation to the frame power of the speech when reverbed; iv) calculate a prescribed frame power, the prescribed frame power being a function of the power of the extracted frame, the measure of the frame importance and the contribution due to late reverberation, the function being configured to decrease the ratio of the prescribed frame power to the power of the extracted frame as the contribution due to late reverberation increases above a critical value, {tilde over (l)}; and v) apply a modification to the frame of the speech received from the speech input producing a modified frame power, wherein the modification is calculated using the prescribed frame power.