audio.clip.GetData() returns no data.

I'm trying to get the samples from an audio clip:

 void Start()
 {
     Float[] samples = new float[audio.clip.samples * audio.clip.channels];
     
     audio.clip.GetData(samples, 0);
     
     for (int i = 0; i < 10; i++) 
     {
         Debug.Log(samples[i]);
     }
 }

When i print out the value of the samples in the "sample" array they're all 0... I read that this was a bug in previous versions of Unity but supposedly it was fixed? Any ideas what the problem is?