the Story of GetSpectrumData, Animator and IEnumerator :D

I am trying to find the frequency of a 'bass' and providing the numerical information of that frequency to the localScale of an Object

My Desire : is to enlarge the object as soon as the bass plays but i want the enlarge animation to complete before it accepts new request to enlarge the object.

For this i am using Coroutines but something is wrong here and i am not able to do perform this.

The problem : Animation playes and before completing accepts new request and then snaps back to larger size again. i mean the One whole animation isn't being played properly

 using UnityEngine;
 using System.Collections;
 
 public class AudioAnim : MonoBehaviour {
 
     public int sample = 64;
     public GameObject green;
     public float[] spectrum;
     public Animator anim;
     public float sam;
 
     void Start () {
         anim = GetComponent<Animator> ();
     }
     
     void Update () {
 
         green.transform.localScale = new Vector3 (1f, 1f, 1f);
 
         
         spectrum = AudioListener.GetSpectrumData (sample, 0, FFTWindow.BlackmanHarris);
         
     
         sam = spectrum [3] + spectrum [33] + spectrum [34] + spectrum [35];
         
         sam = sam * 15;
         
         if(sam > 1f)
         {
             Debug.Log (sam);
             StartCoroutine (bass ());
         }
 
     }
     
     IEnumerator bass()
     {
         anim.Play ("enlarge");
         Debug.Log("in the bass");
         
         yield return new WaitForSeconds(1f);
         anim.Play("idle");
     }
 }