I'm looking to make a multiplayer horror game with one of the main mechanics being the game's internal voice chat. Currently I plan on making it cut in and out so that the players (being on opposite ends of the map from each other) will lose verbal contact with each other. I planned on using unity, so do y'all know of any assets that could help out with this? If not, is there any way I could go about making one of my own systems or would I need to use a different game engine (or just free willy my own engine)?

I don´t know if is this what you mean, but maybe it can help you. It´s a free asset from the Unity Store. Here is the link: https://assetstore.unity.com/packages/tools/audio/distance-equalizer-64870