AudioImporter.forceToMono

public bool forceToMono ;

Description

Force audioclips to mono?

using UnityEngine;
using UnityEditor;

public class Example : AssetPostprocessor
{
    void OnPreprocessAudio()
    {
        AudioImporter audioImporter = assetImporter as AudioImporter;
        if (assetPath.Contains("mono"))
        {
            audioImporter = assetImporter as AudioImporter;
            audioImporter.forceToMono = true;
        }
    }
}