How does one code an audio rolloff along the x axis?

My 2D game requires a sound to have the same volume along the y axis, but a different volume depending on the distance to the camera on the x axis. I can’t figure out how to code the last part of the script though, can you help me? The volume should stay at 0 until the distance is equal/smaller than MinDist at which point the volume should grow linearly until the distance is equeal/smaller than MinDist.

    using System.Collections;
    using System.Collections.Generic;
    using UnityEngine;
    
    public class spatialFader : MonoBehaviour
    {
    	private float pos;
    	private float pos_other;
    	private float dist;
    
    	private AudioSource source;
    
    	public float MinDist;
    	public float MaxDist;
    
    	private float sqrMinDist;
    	private float sqrMaxDist;
    
    	void Start ()
    	{
    		source = GetComponent<AudioSource> ();
    		sqrMinDist = MinDist * MinDist;
    		sqrMaxDist = MaxDist * MaxDist;
    	}
    
    	void Update () {
    
    		pos_other = GameObject.Find("Main Camera").transform.position.x;
    		pos = transform.position.x;
    
    		dist = pos - pos_other;
    		print("Distance to other: " + dist);
    
    //this is the part where I don't know what to do anymore:
    		var t = 
    		source.volume = Mathf.Lerp(0,1,t);
           
    		}
    
    }

I found a solution! Not what I originally had in mind, but for what I’m doing it works fine. At a certain distance it just fades in or out over time.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Audio;

public class SoundRolloff : MonoBehaviour {

	private AudioSource source;

	public float spatialBlend;
	public float minDistance;
	public float maxDistance;
	public float fadeDistance;
	public float volume;

	private float pos;
	private float pos_other;
	private float dist;

	private float currentVolume;


	// Use this for initialization
	void Start () {
		source = GetComponent<AudioSource> ();
		source.volume = 0;
		currentVolume = source.volume;
	}
	
	// Update is called once per frame
	void Update () {
		source = GetComponent<AudioSource> ();
		source.spatialBlend = spatialBlend;
		source.minDistance = minDistance;
		source.maxDistance = maxDistance;
		source.dopplerLevel = 0;
		source.spread = 0;


		pos_other = GameObject.Find("Main Camera").transform.position.x;
		pos = transform.position.x;

		dist = pos - pos_other;

		if (dist < 0) {
			dist = -dist * 2;
		}

		if (dist > fadeDistance){
			source.volume -= volume * Time.deltaTime;
		}

		if ((dist < fadeDistance) && source.volume < volume) {
			source.volume += volume * Time.deltaTime;
		}

			
	}
}