Put this script into the folder named Editor and you will get list with audioClips in your inspector. Set slider to count of elements and empty slots appear.

Put this script into the folder named Editor and you will get list with audioClips in your inspector. Set slider to count of elements and empty slots appear.

using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;


[CustomEditor(typeof(AudioSource))]
public class AudioSourceEditor : Editor
{
    public List<AudioClip> audioClips;

    [Obsolete]
    public override void OnInspectorGUI()
    {
        DrawDefaultInspector();
        EditorGUILayout.LabelField("Audio Clips:");
        EditorGUILayout.BeginHorizontal();
        {
            int count = EditorGUILayout.IntSlider("Count", audioClips.Count, 0, 10);
            if (count != audioClips.Count)
            {
                audioClips.Clear();
                for (int i = 0; i < count; i++)
                {
                    audioClips.Add(null);
                }
            }
        }
        EditorGUILayout.EndHorizontal();
        foreach (AudioClip audioClip in audioClips)
        {
            EditorGUILayout.ObjectField(audioClip, typeof(AudioClip));
        }
    }
}