A method for preparing a speech signal for encoding comprises determining whether
the spectral content of an input speech signal is representative of a defined spectral
characteristic (e.g., a defined characteristic slope). A frequency specific filter
component of a weighting filter is controlled based on the determination of the
spectral content of the speech signal or/and its location in the encoder. A core
weighting filter component of the weighting filter may be maintained regardless
of the spectral content of the speech signal.