AudioClip.GetData
GetData(data: float[], offsetSamples: int): void;
Description

Fills an array with sample data from the clip. The samples are floats ranging from -1.0f to 1.0f. The sample count is determined by the length of the float array.

Use offsetSamples to start the read from a random position in the clip. If the read length from the offset is longer than the clip length, the read will wrap around and read the remaining samples from the start of the clip.
	// Read all the samples from the clip and half the gain
	function Start () {
			var samples = new float[audio.clip.samples * audio.clip.channels];
			audio.clip.GetData(samples, 0);
			for (var i = 0; i < samples.Length; ++i)
				samples[i] = samples[i] * 0.5f;
			audio.clip.SetData(samples, 0);
	}