What Are Neural Frequencies? A Plain-English Guide to How Sound Affects Your Brain

If you have ever read about "sound therapy," "Hz programs," or "brainwave entrainment" and found the explanations either too vague to be useful or too technical to follow, this guide is for you. We will explain exactly what neural frequencies are, how the auditory pathway converts sound into brainwave activity, what the peer-reviewed science shows, and why Tihna is built around 4-week programs rather than one-off audio tracks.

Start Here: What Is a Brainwave?

Your brain runs on electricity. Billions of neurons communicate by firing electrochemical signals, and when millions of neurons fire in coordinated patterns, those patterns create oscillations — rhythmic waves of electrical activity — measurable on the scalp using an electroencephalogram (EEG).

These oscillations are your brainwaves. They vary in frequency (how fast they cycle, measured in hertz) and amplitude (how strong they are), and they change dynamically depending on what you are doing, thinking, or experiencing.

The Five Brainwave Bands

Delta (0.5–4 Hz)
The slowest oscillations. Dominant during deep, dreamless sleep and deep anaesthesia. Critical for physical restoration and memory consolidation during sleep.

Theta (4–8 Hz)
The transition zone between sleep and waking. Active during light sleep, deep meditation, and the hypnagogic state just before sleep onset. A 2025 study in Physiological Reports confirmed that 6 Hz theta stimulation induces cortical entrainment in the precuneus — a key default mode network region involved in self-awareness and meditative states.

Alpha (8–12 Hz)
The resting but awake state. Associated with reduced anxiety, relaxed alertness, and a lowered stress response. A 2026 randomised controlled trial in PLOS ONE found that preoperative frequency program exposure significantly reduced patients' anxiety scores and lowered the anaesthetic dose required for loss of consciousness — a proxy measure for neural arousal state.

Beta (12–30 Hz)
The active, engaged brain. Dominant during conversation, problem-solving, and focused attention. At 15 Hz (sensorimotor rhythm), beta is associated with optimised cortical arousal and attentional performance.

Gamma (30–100 Hz, centred at 40 Hz)
The fastest and most cognitively demanding band. Associated with working memory, executive function, information integration, and peak cognitive performance. A comprehensive 2025 review in the Journal of Central Nervous System Diseases found that 40 Hz stimulation drove improvements in memory, cognitive flexibility, and neural network connectivity across multiple clinical populations.

How the Auditory Pathway Connects Sound to Brain State

The pathway works like this:

1. Sound enters the ear and is converted to electrical signals in the cochlea.
2. The auditory nerve carries those signals to the brainstem's auditory nuclei.
3. The signal reaches the auditory cortex in the temporal lobe, where frequency and pattern are processed.
4. Thalamocortical loops — the brain's internal relay system — distribute auditory processing broadly across cortical networks.

When the auditory system receives a rhythmic signal at a specific frequency, a phenomenon called frequency following response can occur: cortical neurons begin to synchronise their firing to match the rhythmic input. This is neural entrainment — the brain's tendency to match the frequency of an external rhythmic stimulus. EEG studies have repeatedly confirmed frequency following response across auditory, visual, and combined modalities.

What Is Frequency Entrainment?

Entrainment is a physics principle that applies to any oscillating system. Two pendulums on the same surface will gradually synchronise their swings. A metronome sets the tempo for a musician's neural firing. Your brain, as an oscillating electrical system, responds to rhythmic external input by progressively aligning its oscillatory activity to match.

Frequency entrainment through structured audio programs is the application of this principle: delivering a rhythmic auditory signal at a clinically relevant frequency (such as 6 Hz theta or 40 Hz gamma) and allowing the brain's frequency following response to guide it toward that state.

Why Carrier Frequencies Matter

Not all audio delivers frequency programs equally effectively. The carrier frequency — the base tone through which the program is delivered — significantly affects how the auditory cortex processes the signal. Research suggests that mid-range carrier frequencies (roughly 200–500 Hz) produce the strongest frequency following response and the most reliable cortical entrainment. Very low carriers (below 100 Hz) are processed differently by the cochlea and produce less consistent entrainment.

The commonly used range of 200–440 Hz for carrier frequencies is not arbitrary — it maps to the auditory frequencies at which the human brainstem and cortex show the most robust phase-locking to incoming signals. This is why not all "frequency" audio programs are equivalent. Carrier selection, waveform shape, amplitude, and session duration all contribute to how effectively a program entrains the target brain state.

Neuroplasticity: Why Repeated Sessions Build Lasting Change

A single session of frequency entrainment can shift your brainwave state during that session. Think of it like a single gym session: you get a response, but one workout does not change your physiology. What changes physiology is repeated, structured exposure over time. This is neuroplasticity — the brain's capacity to physically reorganise itself in response to experience.

When you repeatedly guide your brain to a specific frequency state:

• Synaptic connections that support that state are strengthened (Hebbian learning: neurons that fire together wire together)
• Thalamocortical network organisation shifts toward the target frequency band
• Default network patterns begin to reflect the practised state, making it more accessible without external stimulus

This is why the clinical literature uses multi-week protocols — not single sessions — to measure meaningful cognitive or psychological outcomes. The structural changes that produce durable improvement take time to build. Tihna's programs are 4 weeks long for this reason.