AudioSourceLoader.cs

using UnityEditor;
using UnityEngine;
using UnityEngine.AddressableAssets;

namespace AssetLoader
{
    [RequireComponent(typeof(AudioSource))]
    public class AudioSourceLoader : MonoBehaviour
    {
        [SerializeField] private AssetReferenceAudioClip audioClip;

#if UNITY_EDITOR
        private void OnValidate()
        {
            if (audioClip == null)
            {
                var clip = GetComponent<AudioSource>().clip;
                if (clip == null) return;
                var guid = AssetDatabase.AssetPathToGUID(AssetDatabase.GetAssetPath(clip));
                audioClip = new AssetReferenceAudioClip(guid);
            }
            else
            {
                GetComponent<AudioSource>().clip = null;
            }
        }
#endif

        private void Start()
        {
            audioClip.LoadAssetAsync<AudioClip>().Completed += handle =>
            {
                GetComponent<AudioSource>().clip = handle.Result;
            };
        }
    }

    // Generics は Inspector に表示されないため定義している
    [System.Serializable]
    public class AssetReferenceAudioClip : AssetReferenceT<AudioClip>
    {
        public AssetReferenceAudioClip(string guid) : base(guid)
        {
        }
    }
}