Frequency guide

A reference to the EEG frequency bands, and to how binaural beats, monaural beats and isochronic tones are made.

Table 1: EEG frequency bands
Band	Range	Associated in EEG with
Delta	0.5–4 Hz	Deep, dreamless sleep
Theta	4–8 Hz	Drowsiness, light sleep, deep meditation
Alpha	8–13 Hz	Relaxed, calm wakefulness, eyes closed
Beta	13–30 Hz	Active thinking, alertness, concentration
Gamma	30–40+ Hz	Intense focus and information processing

These bands describe brain activity measured by EEG. Research on whether audio beats can shift brain activity into these bands is mixed.

Table 2: How each beat type works
	Binaural	Monaural	Isochronic
How it works	A different tone in each ear; the brain perceives the difference	Two tones mixed together, so the beat is real in the air	A single tone pulsing on and off
Headphones	Required	Not required	Not required
Speakers	Doesn't work	Works	Works
Typical carrier	100–500 Hz	100–500 Hz	100–500 Hz

In BeatFractal

In the studio, Ambient music… has a Tones and noise section. Choose a type, a carrier (100–1000 Hz) and a beat or pulse rate (0.5–40 Hz), and add changes: the frequencies glide from one setting to the next. A noise bed (white, pink, brown and other colours) can play with them. They can play under a generated mix, or on their own as the whole track.

The visuals never react to the beats or the noise. Beats at these rates are pulses, and visuals following them would flicker at rates that can trigger photosensitive seizures, so the visuals hear the music only.