getFrequencyData() {

		this.analyser.getByteFrequencyData( this.data );

		return this.data;

	}
Returns an array with frequency data of the audio.

Each item in the array represents the decibel value for a specific frequency.
The frequencies are spread linearly from 0 to 1/2 of the sample rate.
For example, for 48000 sample rate, the last item of the array will represent
the decibel value for 24000 Hz.

@return {Uint8Array} The frequency data.