An apparatus for processing an input audio signal includes an evaluator for evaluating a loudness of the input audio signal to determine a loudness range and an actual loudness value. A calculator determines a compressor transfer function based on the determined loudness range, based on a target loudness range and based on the determined actual loudness value. The calculator further determines at least one loudness range control gain based on the determined compressor transfer function. An adjuster provides an output audio signal based on the input audio signal and based on the at least one determined loudness range control gain. The calculator is configured to determine the compressor transfer function such that a difference between a mean loudness of the output audio signal and a mean loudness of the input audio signal is minimized. A corresponding method is also provided.