Let me understand. You want to make a digital receiver with an audio problem,
A digital receiver for what? AM, FM, SSB, CW, Narrow Band FM.
What kind of audio problem do you want it to have? Distorted, scrambled, unintelligible?
Without more context and a lot more information we have no reason to offer any response to this question. Or are you asking for help repairing a receiver that has a problem? In that case we will need a description of the problem.