Online Tone Generator - Free Pure Tone & Binaural Beats
Binaural Beats
Binaural beats work by playing a slightly different frequency in each ear. Your brain perceives the difference as a single pulsing tone in the centre of your head, even though no speaker is actually moving at that rate.
How the difference tone works
When the left ear receives 432 Hz and the right ear receives 440 Hz, the difference is exactly 8 Hz. This 8 Hz beat is not present in either channel as sound. It emerges inside the auditory nerve, where signals from both ears are compared, and is heard as a slow throb. Because the effect depends on that comparison, binaural beats require headphones: a speaker playing both channels in one room cancels the effect through acoustic mixing.
Bands and the states they are associated with
- Delta0.5 to 4 Hz
- Deep sleep and physical restoration
- Theta4 to 8 Hz
- Meditation, deep relaxation and creativity
- Alpha8 to 13 Hz
- Calm focus and relaxed concentration
- Beta13 to 30 Hz
- Active attention and mental processing
How to set one up on this site
- Switch on the master power so audio starts.
- Set the carrier frequency to 432 Hz using the frequency dial.
- Turn on the binaural offset and set it to 8 Hz.
- Wear headphones, then adjust the master level to a comfortable volume.
- Expect to feel the pulse after a few seconds of listening.
The mapping between these bands and mental states comes largely from correlational studies, not clinical trials. Treat the effect as a tool for relaxation and focus rather than a medical intervention.
What Is an Online Tone Generator and How Does It Work?
An online tone generator synthesizes precise pure tones in real time with the Web Audio API. This guide explains how it works and how to use it for speaker calibration, audio testing and binaural beat experiments.
An audio tone generator is an indispensable instrument for electroacoustic calibration, sound system tuning, audiometry evaluation, and cognitive binaural beats. By synthesizing pure mathematical oscillators across the full human audible spectrum (20 Hz to 22,000 Hz), users can verify loudspeaker linearity, acoustic transducer distortion, room decay, and hearing thresholds with zero latency.
Sine (pure fundamental, 0% harmonic distortion), Triangle (soft odd harmonics), Square (classic hollow chiptune odd harmonics), and Sawtooth (full-spectrum rich bright harmonics).
Generates micro-hertz stereo phase offsets between left and right channels to trigger neural frequency following responses (Alpha 8-12Hz, Theta 4-8Hz, Delta 0.5-4Hz).
Models non-linear hyperbolic tangent transfer curves of vintage 12AX7 triodes, delivering musical second-order even harmonics and gentle saturation compression.
Standardized by ISO 16 in 1955 and the 1939 London Acoustic Conference, concert pitch A4 = 440 Hz harmonized diverse pitch drift across European halls and military brass bands, providing an absolute universal reference for instrument makers.
- What frequency range does this tone generator cover?
- 20 Hz to 22,000 Hz continuous, adjustable logarithmically across the full span.
- Which waveforms are available?
- Four: sine wave, triangle wave, square wave and sawtooth wave.
- What is the total harmonic distortion of the sine wave?
- Below 0.002 percent in pure sine mode. Square and sawtooth waves intentionally contain odd harmonics and are not THD-measured.
- What is the frequency resolution?
- 1 Hz coarse adjustment plus 0.5 Hz fine adjustment.
- Can I export the audio?
- Yes. Export is an uncompressed 44.1 kHz 16-bit linear PCM WAV file rendered in the browser.
- Does the audio leave my device?
- No. All synthesis happens in your browser using the Web Audio API. Nothing is uploaded.
- Do I need to install anything or create an account?
- No. The tool runs entirely in the browser with no signup, no download and no plugin.
- How does binaural beat mode work here?
- A small frequency offset is applied between the left and right channels, for example 432 Hz left and 440 Hz right produces an 8 Hz difference perceived as a pulsing beat.
Rotary knobs support vertical drag, circular angle tracking, mouse wheel rotation, and touch gestures on mobile with electric contact clicks.
Synthesizes authentic hyperbolic tube warmth with even/odd harmonics, alongside tunable radio static hiss and random contact pops.
Render sustained tones, binaural beats, and logarithmic sweeps to uncompressed 16-bit 44.1 kHz WAV files for testing, acoustic tuning, or sharing.