Question Efficient way for implement audio sources

I have a soundmanager script that controls AI and player's audios, its singleton.But i'm not sure about is it efficient way to implement it on my scene ?. İ have 12 audio most of them are very short files such as food step fire sound etc. and couple ambiance sound. İ've researched little bit but couldn't find answer for it.
here is my script ;

Code (CSharp):

1. public class SoundManager : MonoBehaviour
2. {
3.     public static SoundManager instance = null;
4.  
5.     public AudioSource[] audios;
6.  
7.  
8.     private void Awake()
9.     {
10.         if (instance == null)
11.             instance = this;
12.         else if (instance != null)
13.             Destroy(gameObject);
14.  
15.         envorinmentMusicTime = envorinmentMusicTimer;
16.        
17.     }
18.     private void Start()
19.     {
20.         //Music starts at 60 seconds and repeat every 50 seconds
21.         InvokeRepeating("envorinmentMusic",60f,50f);
22.     }
23.  
24.  
25.    
26.  
27.     //--------Movement Sounds--------//
28.     public void playFoodStep()
29.     {
30.         if (!audios[1].isPlaying)
31.         {
32.             //Random volume for realistic sound
33.             audios[1].volume = Random.Range(0.2f, 0.5f);
34.             //audios[1].pitch = Random.Range(0.8f, 1.2f);
35.             audios[1].Play();
36.         }      
37.     }
38.     public void walkSound()
39.     {
40.         audios[1].pitch = 1f;
41.     }
42.     public void runSound()
43.     {
44.         audios[1].pitch = 1.3f;
45.     }
46.     public void stopFoodStep()
47.     {
48.         audios[1].Stop();
49.     }
50.  
51.  
52.     //-----Weapon Sounds-----//
53.     public void fireSound()
54.     {      
55.        audios[2].Play();
56.     }
57.  
58.     public void reloadSound()
59.     {
60.         if (!audios[3].isPlaying)
61.             audios[3].Play();
62.     }
63.  
64.  
65.     //--Ambiance musics--//
66.     public void envorinmentMusic()
67.     {
68.         if(!audios[4].isPlaying && !audios[5].isPlaying)
69.         {
70.             audios[Random.Range(4, 6)].Play();                    
71.         }            
72.     }
73.  
74.  
75. }
76.