A method and apparatus for providing improved intelligibility of contemporaneously perceived audio signals. Differentiation cues are added to monaural audio signals to allow a listener to more effectively comprehend information contained in one or more of the signals. In a specific embodiment, a listener wearing stereo headphones listens to simultaneous monaural radio broadcasts from different stations. A differentiation cue is added to at least one of the audio signals from the radio reception to allow the listener to more effectively focus on and differentiate between the broadcasts.