Hi bigal02,
This would be a nice feature. What you are actually requesting is a way to decrease the dynamic range of the audio (difference is level between the loudest and softest passages). Until it can be added, be aware that some discs already have streams like this, they are referred to variously as "night listening" or something similar. You can check for it from the menu of the disc, usually under the sub menu for audio preferencs or set up. The Copy module does not re-encode the audio, which would be required for this, but Ripper and Converter modules do.