Beta and SMR (12–30 Hz)

Above alpha, activity gets faster and lower in amplitude. This range is conventionally split, and the splits matter more than usual here.

• SMR (sensorimotor rhythm), ~12–15 Hz — recorded over sensorimotor cortex, associated with being alert and physically still.
• Beta, ~15–20 Hz — active, engaged, outward-directed thinking.
• High beta, ~20–30 Hz — intense engagement, and at the top end, associated with anxiety and hypervigilance.

The mistake most focus audio makes

There is an intuition that focus means fast, so more focus means faster. Products follow the intuition and reach for high beta.

The neurofeedback literature points the other way. SMR training — reinforcing 12–15 Hz over sensorimotor cortex — is one of the older and better-explored protocols, historically applied to attention difficulties and to seizure thresholds. The state it targets is calm alertness: attentive, not agitated, physically settled.

High beta, meanwhile, is the range most associated with anxiety at its upper end. If you already feel scattered and wired, a 22 Hz session is more likely to amplify that than resolve it.

So the practical rule is close to the opposite of the intuition: if you feel unfocused because you are anxious, go slower, not faster.

Choosing within the range

12–15 Hz (SMR). The default recommendation for sustained work. Sensorimotor Calm Focus sits at 14 Hz for 19 minutes and is a good first test of whether this range suits you.

15–20 Hz (beta). For work that needs push — drafting, arguing, active problem-solving with momentum. Hyper-Focus Drive runs 18 Hz for 31 minutes.

20 Hz and above (high beta). Genuinely useful for short bursts of dense analytical work, and genuinely counterproductive for long sessions. Deep Analytical Processing is deliberately short at 16 minutes and 22 Hz — the duration is part of the design.

A physical detail worth knowing

Above roughly 40 Hz, binaural delivery stops working — the auditory system can no longer resolve the interaural timing difference the effect depends on. Beta sits comfortably below that, so every mode is available across this range.

What does change is character. A 20 Hz amplitude modulation is fast enough that you stop hearing distinct pulses and start hearing a roughness or buzz in the tone. This is a genuine perceptual boundary, not a fault, and it is why higher-beta sessions tend to use gentler envelopes and lower modulation depth — a hard-gated square wave at 22 Hz is unpleasant in a way the same envelope at 8 Hz is not.

Practical use

• Match the session length to the work block. A 30-minute beta session and a 30-minute task is a better pairing than an open-ended stream.
• Do not stack it on caffeine. If you are already over-aroused, this range compounds it.
• Stop when the block ends. The point of a defined session is that it ends. Running focus audio for six hours is how it becomes wallpaper and stops doing anything at all.