A monaural speech intelligibility predictor unit (MSIP) 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 normalization and transformation unit (N/TU) configured to provide at least one normalization operation of rows and at least one normalization operation of columns of said time-frequency segments X m; e) A segment estimation unit for estimating normalized, essentially noise-free time-frequency segments S̃ m, among said normalized time-frequency segments X̃ m; f) An intermediate speech intelligibility calculation unit (ISIU) 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 sample correlation coefficients between row elements or column elements or all elements of said estimated, normalized, essentially noise-free time segments S̃ m, and said normalized time-frequency segments X̃ m, respectively; g) A final speech intelligibility calculation unit (FSIU) 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. 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 normalization and transformation unit (N/TU) configured to provide at least one normalization operation of rows and at least one normalization operation of columns of said time-frequency segments X m; e) A segment estimation unit for estimating normalized, essentially noise-free time-frequency segments S̃ m, among said normalized time-frequency segments X̃ m; f) An intermediate speech intelligibility calculation unit (ISIU) 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 sample correlation coefficients between row elements or column elements or all elements of said estimated, normalized, essentially noise-free time segments S̃ m, and said normalized time-frequency segments X̃ m, respectively; g) A final speech intelligibility calculation unit (FSIU) 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.