1. A monaural speech intelligibility predictor unit adapted for receiving an information signal x comprising either a clean or noisy and/or processed version of a target speech signal, the speech intelligibility predictor unit being configured to provide as an output a speech intelligibility predictor value d for the information signal, the speech intelligibility predictor unit comprising a) An input unit for providing a time-frequency representation x(k,m) of said information signal x, k being a frequency bin index, k=1, 2,. .. , K, and m being a time index; b) An envelope extraction unit for providing a time-frequency sub-band representation x j (m) of the information signal x representing temporal envelopes, or functions thereof, of frequency sub-band signals x j (m) of said information signal x, j being a frequency sub-band index, j=1, 2,. .. , J, and m being the time index; c) A time-frequency segment division unit for dividing said time-frequency representation x j (m) of the information signal x into time-frequency segments X m corresponding to a number N of successive samples of said-sub-band signals; d) A segment estimation unit for estimating essentially noise-free time-frequency segments S m or normalized and/or transformed versions {tilde over (S)} m thereof, among said time-frequency segments X m , or normalized and/or transformed versions {tilde over (X)} m thereof, respectively; e) An intermediate speech intelligibility calculation unit adapted for providing intermediate speech intelligibility coefficients d m estimating an intelligibility of said time-frequency segment X m , said intermediate speech intelligibility coefficients d m being based on said estimated essentially noise-free time segments S m or normalized and/or transformed versions {tilde over (S)} m thereof, and said time-frequency segments X m , or normalized and/or transformed versions {tilde over (X)} m thereof, respectively; f) A final speech intelligibility calculation unit for calculating a final speech intelligibility predictor d estimating an intelligibility of said information signal x by combining, e.g. averaging or applying a MIN or MAX-function, said intermediate speech intelligibility coefficients d m , or a transformed version thereof, over time.