An audio/speech sender and an audio/speech receiver and methods thereof. The audio/speech sender comprising a core encoder adapted to encode a core frequency band of an input audio/speech signal having a first sampling frequency, wherein the core frequency band comprises frequencies up to a cut-off frequency. The audio/speech sender further comprises a segmentation device adapted to perform a segmentation of the input audio/speech signal into a plurality of segments, a cut-off frequency estimator adapted to estimate a cut-off frequency for each segment and adapted to transmit information about the estimated cut-off frequency to a decoder, a low-pass filter adapted to filter each segment at said estimated cut-off frequency, and a re-sampler adapted to resample the filtered segments with a second sampling frequency that is related to said cut-off frequency in order to generate an audio/speech frame to be encoded by said core encoder.